fix(protocol): align trace schemas with v2/v3 classify rules

RecordedTrace validation now follows classify_value — numeric version
selects v3, otherwise v2 — so mixed pages/states and v2 envelopes with
a version field fail Schema checks before Recall import. Keep standalone
trace_step as a v2|v3 union for tools that validate a single step.

apps/extension/src/lib/trace-reducer.ts

@@ -1,4 +1,4 @@
-import type { DraftTraceStep, PageRef, SelectedOption, Step } from "@/transport/types";
+import type { DraftTraceStep, PageRefV2, SelectedOptionV2, StepV2 } from "@/transport/types";
 
 const CLIPBOARD_KEYS = new Set(["a", "c", "v", "x", "A", "C", "V", "X"]);
 const MODIFIER_ONLY_KEYS = new Set(["Meta", "Control", "Alt", "Shift", "OS", "Hyper", "Super"]);
@@ -60,7 +60,7 @@ function collectUrls(steps: DraftTraceStep[], startUrl?: string): string[] {
 function buildPageRegistry(
   steps: DraftTraceStep[],
   startUrl?: string,
-): { pages: PageRef[]; urlToId: Map<string, string> } {
+): { pages: PageRefV2[]; urlToId: Map<string, string> } {
   const urls = collectUrls(steps, startUrl);
   const urlToId = new Map<string, string>();
   const pages = urls.map((url, index) => {
@@ -90,19 +90,19 @@ function pageUrlForDraft(step: DraftTraceStep, fallbackUrl?: string): string | u
 function effectForNavigation(
   navigatedTo: string | undefined,
   urlToId: Map<string, string>,
-): Step["effect"] {
+): StepV2["effect"] {
   if (!navigatedTo) return undefined;
   const pageId = urlToId.get(navigatedTo);
   if (!pageId) return undefined;
   return { navigated_to: pageId };
 }
 
-function withEffect(step: Step, effect: Step["effect"]): Step {
+function withEffect(step: StepV2, effect: StepV2["effect"]): StepV2 {
   if (!effect) return step;
   return { ...step, effect };
 }
 
-function toSelection(values: string[], labels?: string[]): SelectedOption[] {
+function toSelection(values: string[], labels?: string[]): SelectedOptionV2[] {
   return values.map((value, index) => ({
     value,
     ...(labels?.[index] ? { label: labels[index] } : {}),
@@ -114,7 +114,7 @@ function toV2Step(
   id: number,
   urlToId: Map<string, string>,
   fallbackUrl?: string,
-): Step | null {
+): StepV2 | null {
   if (!shouldIncludeDraft(step)) return null;
 
   const pageUrl = pageUrlForDraft(step, fallbackUrl);
@@ -181,8 +181,8 @@ function toV2Step(
 }
 
 export interface ReducedTrace {
-  pages: PageRef[];
-  steps: Step[];
+  pages: PageRefV2[];
+  steps: StepV2[];
 }
 
 /**
@@ -192,7 +192,7 @@ export interface ReducedTrace {
 export function reduceTraceSteps(steps: DraftTraceStep[], startUrl?: string): ReducedTrace {
   const collapsed = collapseNavigations(steps);
   const { pages, urlToId } = buildPageRegistry(collapsed, startUrl);
-  const out: Step[] = [];
+  const out: StepV2[] = [];
   let id = 1;
   let lastUrl = startUrl;
   for (const draft of collapsed) {
@@ -210,7 +210,7 @@ export function reduceTraceSteps(steps: DraftTraceStep[], startUrl?: string): Re
 export function resolveTraceStartUrl(
   drafts: DraftTraceStep[],
   startUrl?: string,
-  pages?: PageRef[],
+  pages?: PageRefV2[],
 ): string {
   if (startUrl) return startUrl;
   const navigate = drafts.find((step): step is Extract<DraftTraceStep, { op: "navigate" }> => {

apps/extension/src/tools/record.ts

@@ -29,7 +29,7 @@ import type {
   RecordStopParams,
   RecordStopResult,
   RpcError,
-  Trace,
+  TraceV2,
 } from "@/transport/types";
 import { handleNavigate } from "./navigation";
 import {
@@ -50,8 +50,8 @@ interface ActiveRecording {
   steps: DraftTraceStep[];
   startedAt: string;
   startedAtMs: number;
-  finishPromise: Promise<Trace>;
-  resolveFinish: (trace: Trace) => void;
+  finishPromise: Promise<TraceV2>;
+  resolveFinish: (trace: TraceV2) => void;
   rejectFinish: (err: Error) => void;
   settled: boolean;
   finishing: boolean;
@@ -154,7 +154,7 @@ async function sendRecordStartWithAck(
   throw lastError ?? new Error("failed to start recording in content script");
 }
 
-function buildTrace(recording: ActiveRecording): Trace {
+function buildTrace(recording: ActiveRecording): TraceV2 {
   const { pages, steps } = reduceTraceSteps(recording.steps, recording.startUrl);
   const startUrl = resolveTraceStartUrl(recording.steps, recording.startUrl, pages);
   return {
@@ -532,7 +532,7 @@ async function finishRecordingByRequest(
   }
 }
 
-async function finishRecording(sessionId: string, deps: RecordDeps): Promise<Trace | null> {
+async function finishRecording(sessionId: string, deps: RecordDeps): Promise<TraceV2 | null> {
   const recording = recordings.get(sessionId);
   if (!recording || recording.settled || recording.finishing) return null;
   recording.finishing = true;
@@ -574,9 +574,9 @@ export async function handleRecordStart(
   // on the destination page can RECORD_QUERY → rearm → show RecordOverlay
   // instead of flashing ControlOverlay ("Agent 正在控制").
   const requestId = makeRequestId(target.tabId);
-  let resolveFinish!: (trace: Trace) => void;
+  let resolveFinish!: (trace: TraceV2) => void;
   let rejectFinish!: (err: Error) => void;
-  const finishPromise = new Promise<Trace>((resolve, reject) => {
+  const finishPromise = new Promise<TraceV2>((resolve, reject) => {
     resolveFinish = resolve;
     rejectFinish = reject;
   });
@@ -785,9 +785,9 @@ export async function handleRecordAwait(
     return { code: "cancelled", message: "record_await aborted" };
   }
 
-  const outcome = await new Promise<{ trace: Trace } | { error: RpcError }>((resolve) => {
+  const outcome = await new Promise<{ trace: TraceV2 } | { error: RpcError }>((resolve) => {
     let settled = false;
-    const finish = (result: { trace: Trace } | { error: RpcError }) => {
+    const finish = (result: { trace: TraceV2 } | { error: RpcError }) => {
       if (settled) return;
       settled = true;
       if (timer) clearTimeout(timer);

apps/extension/src/transport/types.ts

@@ -657,10 +657,60 @@ export interface EmulateResult {
 }
 
 // --------------------------------------------------------------------------
-// Semantic record payloads — mirror bsk-protocol record.rs (Trace v2)
+// Semantic record payloads mirror the versioned Rust protocol models.
 // --------------------------------------------------------------------------
 
-export interface TargetDescriptor {
+export const TRACE_VERSION_V3 = 3;
+/** Logical v2 identifier. Not a wire field — v2 envelopes omit `version`. */
+export const TRACE_VERSION_V2 = 2;
+export const VOM_FORMAT_VERSION = 1;
+
+export interface TargetDescriptorV3 {
+  ref?: string;
+  role?: string;
+  name?: string;
+  ctx?: string;
+  unmatched?: boolean;
+}
+
+export interface RecorderInfo {
+  bsk: string;
+  vom: number;
+}
+
+export type StopReason = "user_finish" | "cli_stop";
+
+export interface TraceStateV3 {
+  id: string;
+  url: string;
+  title?: string;
+  body: string;
+  truncated?: boolean;
+}
+
+export interface StepResultV3 {
+  state: string;
+}
+
+export interface StepCommonV3 {
+  id: number;
+  state: string;
+  result: StepResultV3;
+}
+
+export type NavigationCause =
+  | "user_typed"
+  | "link"
+  | "form_submit"
+  | "reload"
+  | "history"
+  | "script"
+  | "browser";
+
+export type FillCommit = "enter" | "suggestion" | "blur";
+
+/** Legacy v2 target shape retained for existing record producers. */
+export interface TargetDescriptorV2 {
   role?: string;
   name?: string;
   tag: string;
@@ -673,43 +723,43 @@ export interface TraceEntry {
   start_url: string;
 }
 
-export interface PageRef {
+export interface PageRefV2 {
   id: string;
   url: string;
   title?: string;
 }
 
-export interface SelectedOption {
+export interface SelectedOptionV2 {
   value: string;
   label?: string;
 }
 
-export interface StepEffect {
+export interface StepEffectV2 {
   navigated_to: string;
 }
 
-export interface StepCommon {
+export interface StepCommonV2 {
   id: number;
   page: string;
-  effect?: StepEffect;
+  effect?: StepEffectV2;
 }
 
 /** Capture/buffer draft before v2 reduction. */
 export type DraftTraceStep =
   | {
       op: "click";
-      target: TargetDescriptor;
+      target: TargetDescriptorV2;
       navigated_to?: string;
       page_url?: string;
     }
   | {
       op: "hover";
-      target: TargetDescriptor;
+      target: TargetDescriptorV2;
       page_url?: string;
     }
   | {
       op: "fill";
-      target: TargetDescriptor;
+      target: TargetDescriptorV2;
       value: string;
       redacted?: boolean;
       page_url?: string;
@@ -717,14 +767,14 @@ export type DraftTraceStep =
   | {
       op: "press";
       key: string;
-      target?: TargetDescriptor;
+      target?: TargetDescriptorV2;
       modifiers?: KeyModifier[];
       navigated_to?: string;
       page_url?: string;
     }
   | {
       op: "select";
-      target: TargetDescriptor;
+      target: TargetDescriptorV2;
       values: string[];
       labels?: string[];
       navigated_to?: string;
@@ -737,34 +787,75 @@ export type DraftTraceStep =
     };
 
 /** Exported record-only step (trace v2). */
-export type Step =
-  | ({ op: "navigate" } & StepCommon & { to: string })
-  | ({ op: "click" } & StepCommon & { target: TargetDescriptor })
-  | ({ op: "hover" } & StepCommon & { target: TargetDescriptor })
-  | ({ op: "fill" } & StepCommon & {
-        target: TargetDescriptor;
+export type StepV2 =
+  | ({ op: "navigate" } & StepCommonV2 & { to: string })
+  | ({ op: "click" } & StepCommonV2 & { target: TargetDescriptorV2 })
+  | ({ op: "hover" } & StepCommonV2 & { target: TargetDescriptorV2 })
+  | ({ op: "fill" } & StepCommonV2 & {
+        target: TargetDescriptorV2;
         value: string;
         redacted?: boolean;
       })
-  | ({ op: "select" } & StepCommon & {
-        target: TargetDescriptor;
-        selection: SelectedOption[];
+  | ({ op: "select" } & StepCommonV2 & {
+        target: TargetDescriptorV2;
+        selection: SelectedOptionV2[];
       })
-  | ({ op: "press" } & StepCommon & {
+  | ({ op: "press" } & StepCommonV2 & {
         key: string;
         modifiers?: KeyModifier[];
-        target?: TargetDescriptor;
+        target?: TargetDescriptorV2;
       });
 
-export interface Trace {
+export interface TraceV2 {
   recorded_at: string;
   started_at?: string;
   purpose?: string;
   entry: TraceEntry;
-  pages: PageRef[];
-  steps: Step[];
+  pages: PageRefV2[];
+  steps: StepV2[];
 }
 
+export interface SelectedOptionV3 {
+  value: string;
+  label?: string;
+}
+
+export type StepV3 =
+  | ({ op: "navigate" } & StepCommonV3 & { to: string; cause: NavigationCause })
+  | ({ op: "click" } & StepCommonV3 & { target: TargetDescriptorV3 })
+  | ({ op: "hover" } & StepCommonV3 & { target: TargetDescriptorV3 })
+  | ({ op: "fill" } & StepCommonV3 & {
+        target: TargetDescriptorV3;
+        value: string;
+        commit: FillCommit;
+        redacted?: boolean;
+      })
+  | ({ op: "select" } & StepCommonV3 & {
+        target: TargetDescriptorV3;
+        selection?: SelectedOptionV3[];
+      })
+  | ({ op: "press" } & StepCommonV3 & {
+        key: string;
+        modifiers?: KeyModifier[];
+        target?: TargetDescriptorV3;
+      })
+  | ({ op: "scroll" } & StepCommonV3);
+
+export interface TraceV3 {
+  version: typeof TRACE_VERSION_V3;
+  recorded_at: string;
+  started_at?: string;
+  purpose?: string;
+  stopped_by: StopReason;
+  entry: TraceEntry;
+  recorder: RecorderInfo;
+  states: TraceStateV3[];
+  steps: StepV3[];
+}
+
+export type RecordedTrace = TraceV2 | TraceV3;
+export type RecordedStep = StepV2 | StepV3;
+
 export interface RecordStartParams {
   session_id: string;
   tab_id?: number;
@@ -782,7 +873,7 @@ export interface RecordStopParams {
 }
 
 export interface RecordStopResult {
-  trace: Trace;
+  trace: RecordedTrace;
 }
 
 export interface RecordAwaitParams {
@@ -791,5 +882,5 @@ export interface RecordAwaitParams {
 }
 
 export interface RecordAwaitResult {
-  trace: Trace;
+  trace: RecordedTrace;
 }

crates/bsk-cli/src/cli/record.rs

@@ -8,7 +8,7 @@ use anyhow::Context;
 use bsk_protocol::Method;
 use bsk_protocol::tools::{
     RecordAwaitParams, RecordAwaitResult, RecordStartParams, RecordStartResult, RecordStopParams,
-    RecordStopResult, Trace,
+    RecordStopResult, RecordedTrace,
 };
 use clap::{Args, Subcommand};
 
@@ -190,7 +190,7 @@ fn record_await_ipc_timeout(timeout_ms: u32) -> Duration {
         .unwrap_or(Duration::from_secs(u64::from(timeout_ms / 1_000) + 15))
 }
 
-fn write_trace_file(output: &PathBuf, trace: &Trace) -> Result<(), CliError> {
+fn write_trace_file(output: &PathBuf, trace: &RecordedTrace) -> Result<(), CliError> {
     let json = serde_json::to_string_pretty(trace)
         .context("serialize trace JSON")
         .map_err(CliError::Local)?;
@@ -207,7 +207,7 @@ fn write_trace_file(output: &PathBuf, trace: &Trace) -> Result<(), CliError> {
     Ok(())
 }
 
-fn render_finish(trace: &Trace, output: &PathBuf, format: Format) -> Result<(), CliError> {
+fn render_finish(trace: &RecordedTrace, output: &PathBuf, format: Format) -> Result<(), CliError> {
     match format {
         Format::Json => {
             println!(
@@ -221,7 +221,11 @@ fn render_finish(trace: &Trace, output: &PathBuf, format: Format) -> Result<(),
             );
         }
         Format::Human => {
-            println!("saved {} steps to {}", trace.steps.len(), output.display());
+            let step_count = match trace {
+                RecordedTrace::V2(trace) => trace.steps.len(),
+                RecordedTrace::V3(trace) => trace.steps.len(),
+            };
+            println!("saved {step_count} steps to {}", output.display());
         }
     }
     Ok(())

crates/bsk-cli/src/daemon/start.rs

@@ -15,7 +15,6 @@ use std::net::{IpAddr, Ipv4Addr, SocketAddr};
 use std::path::Path;
 use std::sync::Arc;
 use std::sync::Mutex;
-use std::sync::atomic::{AtomicUsize, Ordering};
 use std::time::{Duration, Instant};
 
 use anyhow::{Context, Result};
@@ -291,8 +290,7 @@ pub fn run_foreground(cfg: DaemonConfig) -> Result<()> {
         });
 
         let started_at = Instant::now();
-        let activity: Arc<Mutex<Instant>> = Arc::new(Mutex::new(started_at));
-        let active_ipc_connections = Arc::new(AtomicUsize::new(0));
+        let activity = Arc::new(Mutex::new(IpcActivityState::new(started_at)));
         let (ipc_shutdown_tx, ipc_shutdown_rx) = tokio::sync::oneshot::channel::<()>();
         let status = ipc::DaemonStatus {
             started_at,
@@ -314,18 +312,14 @@ pub fn run_foreground(cfg: DaemonConfig) -> Result<()> {
             let handler = handler.clone();
             let ipc_open = {
                 let activity = activity.clone();
-                let active = active_ipc_connections.clone();
                 move || {
-                    active.fetch_add(1, Ordering::SeqCst);
-                    record_activity(&activity);
+                    record_ipc_open(&activity);
                 }
             };
             let ipc_close = {
                 let activity = activity.clone();
-                let active = active_ipc_connections.clone();
                 move || {
-                    active.fetch_sub(1, Ordering::SeqCst);
-                    record_activity(&activity);
+                    record_ipc_close(&activity);
                 }
             };
             tokio::spawn(ipc::serve(
@@ -344,7 +338,6 @@ pub fn run_foreground(cfg: DaemonConfig) -> Result<()> {
         let idle_task = {
             let activity = activity.clone();
             let state = Arc::clone(&state);
-            let active_ipc_connections = active_ipc_connections.clone();
             let daemon_idle = cfg.daemon_idle;
             tokio::spawn(async move {
                 let tick = (daemon_idle / 4).max(Duration::from_millis(250));
@@ -352,22 +345,19 @@ pub fn run_foreground(cfg: DaemonConfig) -> Result<()> {
                 ticker.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay);
                 loop {
                     ticker.tick().await;
-                    let last = match activity.lock() {
-                        Ok(a) => *a,
-                        Err(p) => *p.into_inner(),
-                    };
-                    if last.elapsed() < daemon_idle {
+                    let ipc_is_idle =
+                        lock_activity(&activity).should_exit_for_idle(Instant::now(), daemon_idle);
+                    if !ipc_is_idle {
                         continue;
                     }
-                    // Bridge from M2/M3 (which only knew about connection
-                    // counts) to M4/M5 (browser + session registries):
-                    // hold the daemon alive while any IPC client is
-                    // connected, any browser is paired, or any session
-                    // is live (design §3.2).
-                    if active_ipc_connections.load(Ordering::SeqCst) > 0
-                        || !state.browsers.is_empty()
-                        || !state.sessions.is_empty()
-                    {
+                    // IPC liveness (open-connection count + idle window) is already
+                    // enforced above by `should_exit_for_idle`, which reads
+                    // `IpcActivityState` under one lock and returns true only when
+                    // there are zero connections AND the idle interval has elapsed.
+                    // Here we additionally hold the daemon alive while any browser
+                    // is paired or any session is live (design §3.2, M4/M5
+                    // registries).
+                    if !state.browsers.is_empty() || !state.sessions.is_empty() {
                         continue;
                     }
                     info!(
@@ -682,10 +672,55 @@ fn restart_start_args(cfg: &DaemonConfig) -> StartArgs {
     }
 }
 
-fn record_activity(activity: &Arc<Mutex<Instant>>) {
-    if let Ok(mut a) = activity.lock() {
-        *a = Instant::now();
+#[derive(Debug)]
+struct IpcActivityState {
+    last_activity: Instant,
+    active_connections: usize,
+}
+
+impl IpcActivityState {
+    fn new(now: Instant) -> Self {
+        Self {
+            last_activity: now,
+            active_connections: 0,
+        }
     }
+
+    fn touch(&mut self, now: Instant) {
+        self.last_activity = now;
+    }
+
+    fn opened(&mut self, now: Instant) {
+        self.active_connections = self.active_connections.saturating_add(1);
+        self.last_activity = now;
+    }
+
+    fn closed(&mut self, now: Instant) {
+        self.active_connections = self.active_connections.saturating_sub(1);
+        self.last_activity = now;
+    }
+
+    fn should_exit_for_idle(&self, now: Instant, idle: Duration) -> bool {
+        self.active_connections == 0 && now.saturating_duration_since(self.last_activity) >= idle
+    }
+}
+
+fn lock_activity(
+    activity: &Arc<Mutex<IpcActivityState>>,
+) -> std::sync::MutexGuard<'_, IpcActivityState> {
+    activity.lock().unwrap_or_else(|poison| poison.into_inner())
+}
+
+fn record_activity(activity: &Arc<Mutex<IpcActivityState>>) {
+    lock_activity(activity).touch(Instant::now());
+}
+
+fn record_ipc_open(activity: &Arc<Mutex<IpcActivityState>>) {
+    lock_activity(activity).opened(Instant::now());
+}
+
+fn record_ipc_close(activity: &Arc<Mutex<IpcActivityState>>) {
+    lock_activity(activity).closed(Instant::now());
 }
 
 /// Initialise tracing for the daemon: write a daily-rotated file in
@@ -1068,4 +1103,37 @@ mod tests {
         assert_eq!(args.session_idle, Some(Duration::from_secs(11)));
         assert_eq!(args.daemon_idle, Some(Duration::from_secs(22)));
     }
+
+    #[test]
+    fn ipc_close_restarts_the_idle_window_atomically() {
+        let started = Instant::now();
+        let idle = Duration::from_secs(10);
+        let mut activity = IpcActivityState::new(started);
+
+        activity.opened(started);
+        let closed_at = started + Duration::from_secs(30);
+        assert!(
+            !activity.should_exit_for_idle(closed_at, idle),
+            "an open IPC connection must hold the daemon alive"
+        );
+
+        activity.closed(closed_at);
+        assert_eq!(activity.active_connections, 0);
+        assert_eq!(activity.last_activity, closed_at);
+        assert!(!activity.should_exit_for_idle(closed_at, idle));
+        assert!(!activity.should_exit_for_idle(closed_at + idle - Duration::from_millis(1), idle));
+        assert!(activity.should_exit_for_idle(closed_at + idle, idle));
+    }
+
+    #[test]
+    fn ipc_activity_keeps_the_daemon_alive_until_a_full_idle_interval_passes() {
+        let started = Instant::now();
+        let idle = Duration::from_secs(10);
+        let mut activity = IpcActivityState::new(started);
+        let request_at = started + Duration::from_secs(20);
+
+        activity.touch(request_at);
+        assert!(!activity.should_exit_for_idle(request_at + Duration::from_secs(9), idle));
+        assert!(activity.should_exit_for_idle(request_at + idle, idle));
+    }
 }

crates/bsk-protocol/schema/tool_record_await_result.json

@@ -7,10 +7,18 @@
   ],
   "properties": {
     "trace": {
-      "$ref": "#/definitions/Trace"
+      "$ref": "#/definitions/RecordedTrace"
     }
   },
   "definitions": {
+    "FillCommit": {
+      "type": "string",
+      "enum": [
+        "enter",
+        "suggestion",
+        "blur"
+      ]
+    },
     "KeyModifier": {
       "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
       "type": "string",
@@ -21,7 +29,19 @@
         "shift"
       ]
     },
-    "PageRef": {
+    "NavigationCause": {
+      "type": "string",
+      "enum": [
+        "user_typed",
+        "link",
+        "form_submit",
+        "reload",
+        "history",
+        "script",
+        "browser"
+      ]
+    },
+    "PageRefV2": {
       "description": "Page context dictionary entry — referenced by steps via `page` id.",
       "type": "object",
       "required": [
@@ -43,7 +63,42 @@
         }
       }
     },
-    "SelectedOption": {
+    "RecordedTrace": {
+      "if": {
+        "required": [
+          "version"
+        ],
+        "properties": {
+          "version": {
+            "type": "integer"
+          }
+        }
+      },
+      "then": {
+        "$ref": "#/definitions/TraceV3"
+      },
+      "else": {
+        "$ref": "#/definitions/TraceV2"
+      }
+    },
+    "RecorderInfo": {
+      "type": "object",
+      "required": [
+        "bsk",
+        "vom"
+      ],
+      "properties": {
+        "bsk": {
+          "type": "string"
+        },
+        "vom": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        }
+      }
+    },
+    "SelectedOptionV2": {
       "description": "One selected option (`select` op).",
       "type": "object",
       "required": [
@@ -61,11 +116,53 @@
         }
       }
     },
-    "Step": {
-      "description": "One recorded user action — discriminated union by `op`.",
+    "SelectedOptionV3": {
+      "description": "One selected option (`select` op).",
+      "type": "object",
+      "required": [
+        "value"
+      ],
+      "properties": {
+        "label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    "StepEffectV2": {
+      "description": "Observed navigation after a step (objective fact only).",
+      "type": "object",
+      "required": [
+        "navigated_to"
+      ],
+      "properties": {
+        "navigated_to": {
+          "description": "Reference into `pages[]` for the destination page.",
+          "type": "string"
+        }
+      }
+    },
+    "StepResultV3": {
+      "type": "object",
+      "required": [
+        "state"
+      ],
+      "properties": {
+        "state": {
+          "type": "string"
+        }
+      }
+    },
+    "StepV2": {
+      "description": "One recorded user action — discriminated union by `op` (v2).",
       "oneOf": [
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -77,7 +174,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -105,7 +202,7 @@
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -117,7 +214,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -140,12 +237,12 @@
               "type": "string"
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -157,7 +254,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -180,12 +277,12 @@
               "type": "string"
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -198,7 +295,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -227,7 +324,7 @@
               ]
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             },
             "value": {
               "type": "string"
@@ -235,7 +332,7 @@
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -248,7 +345,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -273,16 +370,16 @@
             "selection": {
               "type": "array",
               "items": {
-                "$ref": "#/definitions/SelectedOption"
+                "$ref": "#/definitions/SelectedOptionV2"
               }
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -294,7 +391,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -331,7 +428,7 @@
             "target": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/TargetDescriptor"
+                  "$ref": "#/definitions/TargetDescriptorV2"
                 },
                 {
                   "type": "null"
@@ -342,21 +439,294 @@
         }
       ]
     },
-    "StepEffect": {
-      "description": "Observed navigation after a step (objective fact only).",
-      "type": "object",
-      "required": [
-        "navigated_to"
-      ],
-      "properties": {
-        "navigated_to": {
-          "description": "Reference into `pages[]` for the destination page.",
-          "type": "string"
+    "StepV3": {
+      "description": "One recorded user action — discriminated union by `op`.",
+      "oneOf": [
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "cause",
+            "id",
+            "op",
+            "result",
+            "state",
+            "to"
+          ],
+          "properties": {
+            "cause": {
+              "$ref": "#/definitions/NavigationCause"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "navigate"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "to": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "click"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "hover"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "commit",
+            "id",
+            "op",
+            "result",
+            "state",
+            "target",
+            "value"
+          ],
+          "properties": {
+            "commit": {
+              "$ref": "#/definitions/FillCommit"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "fill"
+              ]
+            },
+            "redacted": {
+              "type": "boolean"
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            },
+            "value": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "select"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "selection": {
+              "type": "array",
+              "items": {
+                "$ref": "#/definitions/SelectedOptionV3"
+              }
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "key",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "key": {
+              "type": "string"
+            },
+            "modifiers": {
+              "type": [
+                "array",
+                "null"
+              ],
+              "items": {
+                "$ref": "#/definitions/KeyModifier"
+              }
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "press"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/TargetDescriptorV3"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "scroll"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            }
+          }
         }
-      }
+      ]
     },
-    "TargetDescriptor": {
-      "description": "Stable semantic handle for an interacted element.\n\n`name` and `nearby_label` are **untrusted page text**.",
+    "StopReason": {
+      "type": "string",
+      "enum": [
+        "user_finish",
+        "cli_stop"
+      ]
+    },
+    "TargetDescriptorV2": {
+      "description": "Stable semantic handle for an interacted element (v2).\n\n`name` and `nearby_label` are **untrusted page text**.",
       "type": "object",
       "required": [
         "tag"
@@ -397,8 +767,83 @@
         }
       }
     },
-    "Trace": {
-      "description": "Persisted user-action trace exported by `tool.record_stop` / `await`.",
+    "TargetDescriptorV3": {
+      "description": "Stable semantic handle for an interacted element within a page observation.",
+      "type": "object",
+      "properties": {
+        "ctx": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "ref": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "role": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "unmatched": {
+          "type": "boolean"
+        }
+      }
+    },
+    "TraceEntry": {
+      "type": "object",
+      "required": [
+        "start_url"
+      ],
+      "properties": {
+        "start_url": {
+          "type": "string"
+        }
+      }
+    },
+    "TraceStateV3": {
+      "description": "Page observation dictionary entry — referenced by steps via `state` / `result.state`.",
+      "type": "object",
+      "required": [
+        "body",
+        "id",
+        "url"
+      ],
+      "properties": {
+        "body": {
+          "description": "Full page observation (front matter + VOM body + annotations).",
+          "type": "string"
+        },
+        "id": {
+          "type": "string"
+        },
+        "title": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "truncated": {
+          "type": "boolean"
+        },
+        "url": {
+          "type": "string"
+        }
+      }
+    },
+    "TraceV2": {
+      "title": "TraceV2",
+      "description": "Persisted user-action trace exported by legacy `tool.record_stop` / `await`.\n\nUnknown extension fields are ignored so older traces remain readable. `states[]` and a numeric `version` are reserved for Trace v3 / `RecordedTrace` classification.",
       "type": "object",
       "required": [
         "entry",
@@ -413,11 +858,10 @@
         "pages": {
           "type": "array",
           "items": {
-            "$ref": "#/definitions/PageRef"
+            "$ref": "#/definitions/PageRefV2"
           }
         },
         "purpose": {
-          "description": "Optional user-provided goal from `--purpose` (metadata only).",
           "type": [
             "string",
             "null"
@@ -433,25 +877,76 @@
             "null"
           ]
         },
+        "states": false,
         "steps": {
           "type": "array",
           "items": {
-            "$ref": "#/definitions/Step"
+            "$ref": "#/definitions/StepV2"
+          }
+        },
+        "version": {
+          "description": "Numeric version selects Trace v3. Legacy v2 envelopes omit this field.",
+          "not": {
+            "type": "integer"
           }
         }
       }
     },
-    "TraceEntry": {
-      "description": "Recording entry point — first URL the flow starts from.",
+    "TraceV3": {
+      "description": "Wire trace returned by `tool.record_stop` / `await`.",
       "type": "object",
       "required": [
-        "start_url"
+        "entry",
+        "recorded_at",
+        "recorder",
+        "states",
+        "steps",
+        "stopped_by",
+        "version"
       ],
       "properties": {
-        "start_url": {
+        "entry": {
+          "$ref": "#/definitions/TraceEntry"
+        },
+        "purpose": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "recorded_at": {
           "type": "string"
+        },
+        "recorder": {
+          "$ref": "#/definitions/RecorderInfo"
+        },
+        "started_at": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "states": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/TraceStateV3"
+          }
+        },
+        "steps": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/StepV3"
+          }
+        },
+        "stopped_by": {
+          "$ref": "#/definitions/StopReason"
+        },
+        "version": {
+          "type": "integer",
+          "const": 3
         }
-      }
+      },
+      "additionalProperties": false
     }
   }
 }

crates/bsk-protocol/schema/tool_record_stop_result.json

@@ -7,10 +7,18 @@
   ],
   "properties": {
     "trace": {
-      "$ref": "#/definitions/Trace"
+      "$ref": "#/definitions/RecordedTrace"
     }
   },
   "definitions": {
+    "FillCommit": {
+      "type": "string",
+      "enum": [
+        "enter",
+        "suggestion",
+        "blur"
+      ]
+    },
     "KeyModifier": {
       "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
       "type": "string",
@@ -21,7 +29,19 @@
         "shift"
       ]
     },
-    "PageRef": {
+    "NavigationCause": {
+      "type": "string",
+      "enum": [
+        "user_typed",
+        "link",
+        "form_submit",
+        "reload",
+        "history",
+        "script",
+        "browser"
+      ]
+    },
+    "PageRefV2": {
       "description": "Page context dictionary entry — referenced by steps via `page` id.",
       "type": "object",
       "required": [
@@ -43,7 +63,42 @@
         }
       }
     },
-    "SelectedOption": {
+    "RecordedTrace": {
+      "if": {
+        "required": [
+          "version"
+        ],
+        "properties": {
+          "version": {
+            "type": "integer"
+          }
+        }
+      },
+      "then": {
+        "$ref": "#/definitions/TraceV3"
+      },
+      "else": {
+        "$ref": "#/definitions/TraceV2"
+      }
+    },
+    "RecorderInfo": {
+      "type": "object",
+      "required": [
+        "bsk",
+        "vom"
+      ],
+      "properties": {
+        "bsk": {
+          "type": "string"
+        },
+        "vom": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        }
+      }
+    },
+    "SelectedOptionV2": {
       "description": "One selected option (`select` op).",
       "type": "object",
       "required": [
@@ -61,11 +116,53 @@
         }
       }
     },
-    "Step": {
-      "description": "One recorded user action — discriminated union by `op`.",
+    "SelectedOptionV3": {
+      "description": "One selected option (`select` op).",
+      "type": "object",
+      "required": [
+        "value"
+      ],
+      "properties": {
+        "label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    "StepEffectV2": {
+      "description": "Observed navigation after a step (objective fact only).",
+      "type": "object",
+      "required": [
+        "navigated_to"
+      ],
+      "properties": {
+        "navigated_to": {
+          "description": "Reference into `pages[]` for the destination page.",
+          "type": "string"
+        }
+      }
+    },
+    "StepResultV3": {
+      "type": "object",
+      "required": [
+        "state"
+      ],
+      "properties": {
+        "state": {
+          "type": "string"
+        }
+      }
+    },
+    "StepV2": {
+      "description": "One recorded user action — discriminated union by `op` (v2).",
       "oneOf": [
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -77,7 +174,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -105,7 +202,7 @@
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -117,7 +214,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -140,12 +237,12 @@
               "type": "string"
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -157,7 +254,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -180,12 +277,12 @@
               "type": "string"
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -198,7 +295,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -227,7 +324,7 @@
               ]
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             },
             "value": {
               "type": "string"
@@ -235,7 +332,7 @@
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -248,7 +345,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -273,16 +370,16 @@
             "selection": {
               "type": "array",
               "items": {
-                "$ref": "#/definitions/SelectedOption"
+                "$ref": "#/definitions/SelectedOptionV2"
               }
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -294,7 +391,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -331,7 +428,7 @@
             "target": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/TargetDescriptor"
+                  "$ref": "#/definitions/TargetDescriptorV2"
                 },
                 {
                   "type": "null"
@@ -342,21 +439,294 @@
         }
       ]
     },
-    "StepEffect": {
-      "description": "Observed navigation after a step (objective fact only).",
-      "type": "object",
-      "required": [
-        "navigated_to"
-      ],
-      "properties": {
-        "navigated_to": {
-          "description": "Reference into `pages[]` for the destination page.",
-          "type": "string"
+    "StepV3": {
+      "description": "One recorded user action — discriminated union by `op`.",
+      "oneOf": [
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "cause",
+            "id",
+            "op",
+            "result",
+            "state",
+            "to"
+          ],
+          "properties": {
+            "cause": {
+              "$ref": "#/definitions/NavigationCause"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "navigate"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "to": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "click"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "hover"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "commit",
+            "id",
+            "op",
+            "result",
+            "state",
+            "target",
+            "value"
+          ],
+          "properties": {
+            "commit": {
+              "$ref": "#/definitions/FillCommit"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "fill"
+              ]
+            },
+            "redacted": {
+              "type": "boolean"
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            },
+            "value": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "select"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "selection": {
+              "type": "array",
+              "items": {
+                "$ref": "#/definitions/SelectedOptionV3"
+              }
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "key",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "key": {
+              "type": "string"
+            },
+            "modifiers": {
+              "type": [
+                "array",
+                "null"
+              ],
+              "items": {
+                "$ref": "#/definitions/KeyModifier"
+              }
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "press"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/TargetDescriptorV3"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "scroll"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            }
+          }
         }
-      }
+      ]
     },
-    "TargetDescriptor": {
-      "description": "Stable semantic handle for an interacted element.\n\n`name` and `nearby_label` are **untrusted page text**.",
+    "StopReason": {
+      "type": "string",
+      "enum": [
+        "user_finish",
+        "cli_stop"
+      ]
+    },
+    "TargetDescriptorV2": {
+      "description": "Stable semantic handle for an interacted element (v2).\n\n`name` and `nearby_label` are **untrusted page text**.",
       "type": "object",
       "required": [
         "tag"
@@ -397,8 +767,83 @@
         }
       }
     },
-    "Trace": {
-      "description": "Persisted user-action trace exported by `tool.record_stop` / `await`.",
+    "TargetDescriptorV3": {
+      "description": "Stable semantic handle for an interacted element within a page observation.",
+      "type": "object",
+      "properties": {
+        "ctx": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "ref": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "role": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "unmatched": {
+          "type": "boolean"
+        }
+      }
+    },
+    "TraceEntry": {
+      "type": "object",
+      "required": [
+        "start_url"
+      ],
+      "properties": {
+        "start_url": {
+          "type": "string"
+        }
+      }
+    },
+    "TraceStateV3": {
+      "description": "Page observation dictionary entry — referenced by steps via `state` / `result.state`.",
+      "type": "object",
+      "required": [
+        "body",
+        "id",
+        "url"
+      ],
+      "properties": {
+        "body": {
+          "description": "Full page observation (front matter + VOM body + annotations).",
+          "type": "string"
+        },
+        "id": {
+          "type": "string"
+        },
+        "title": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "truncated": {
+          "type": "boolean"
+        },
+        "url": {
+          "type": "string"
+        }
+      }
+    },
+    "TraceV2": {
+      "title": "TraceV2",
+      "description": "Persisted user-action trace exported by legacy `tool.record_stop` / `await`.\n\nUnknown extension fields are ignored so older traces remain readable. `states[]` and a numeric `version` are reserved for Trace v3 / `RecordedTrace` classification.",
       "type": "object",
       "required": [
         "entry",
@@ -413,11 +858,10 @@
         "pages": {
           "type": "array",
           "items": {
-            "$ref": "#/definitions/PageRef"
+            "$ref": "#/definitions/PageRefV2"
           }
         },
         "purpose": {
-          "description": "Optional user-provided goal from `--purpose` (metadata only).",
           "type": [
             "string",
             "null"
@@ -433,25 +877,76 @@
             "null"
           ]
         },
+        "states": false,
         "steps": {
           "type": "array",
           "items": {
-            "$ref": "#/definitions/Step"
+            "$ref": "#/definitions/StepV2"
+          }
+        },
+        "version": {
+          "description": "Numeric version selects Trace v3. Legacy v2 envelopes omit this field.",
+          "not": {
+            "type": "integer"
           }
         }
       }
     },
-    "TraceEntry": {
-      "description": "Recording entry point — first URL the flow starts from.",
+    "TraceV3": {
+      "description": "Wire trace returned by `tool.record_stop` / `await`.",
       "type": "object",
       "required": [
-        "start_url"
+        "entry",
+        "recorded_at",
+        "recorder",
+        "states",
+        "steps",
+        "stopped_by",
+        "version"
       ],
       "properties": {
-        "start_url": {
+        "entry": {
+          "$ref": "#/definitions/TraceEntry"
+        },
+        "purpose": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "recorded_at": {
           "type": "string"
+        },
+        "recorder": {
+          "$ref": "#/definitions/RecorderInfo"
+        },
+        "started_at": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "states": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/TraceStateV3"
+          }
+        },
+        "steps": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/StepV3"
+          }
+        },
+        "stopped_by": {
+          "$ref": "#/definitions/StopReason"
+        },
+        "version": {
+          "type": "integer",
+          "const": 3
         }
-      }
+      },
+      "additionalProperties": false
     }
   }
 }

crates/bsk-protocol/schema/trace.json

@@ -1,49 +1,31 @@
 {
   "$schema": "http://json-schema.org/draft-07/schema#",
-  "title": "Trace",
-  "description": "Persisted user-action trace exported by `tool.record_stop` / `await`.",
-  "type": "object",
-  "required": [
-    "entry",
-    "pages",
-    "recorded_at",
-    "steps"
-  ],
-  "properties": {
-    "entry": {
-      "$ref": "#/definitions/TraceEntry"
-    },
-    "pages": {
-      "type": "array",
-      "items": {
-        "$ref": "#/definitions/PageRef"
-      }
-    },
-    "purpose": {
-      "description": "Optional user-provided goal from `--purpose` (metadata only).",
-      "type": [
-        "string",
-        "null"
-      ]
-    },
-    "recorded_at": {
-      "description": "RFC 3339 timestamp when recording stopped.",
-      "type": "string"
-    },
-    "started_at": {
-      "type": [
-        "string",
-        "null"
-      ]
-    },
-    "steps": {
-      "type": "array",
-      "items": {
-        "$ref": "#/definitions/Step"
+  "title": "RecordedTrace",
+  "if": {
+    "required": [
+      "version"
+    ],
+    "properties": {
+      "version": {
+        "type": "integer"
       }
     }
   },
+  "then": {
+    "$ref": "#/definitions/TraceV3"
+  },
+  "else": {
+    "$ref": "#/definitions/TraceV2"
+  },
   "definitions": {
+    "FillCommit": {
+      "type": "string",
+      "enum": [
+        "enter",
+        "suggestion",
+        "blur"
+      ]
+    },
     "KeyModifier": {
       "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
       "type": "string",
@@ -54,7 +36,19 @@
         "shift"
       ]
     },
-    "PageRef": {
+    "NavigationCause": {
+      "type": "string",
+      "enum": [
+        "user_typed",
+        "link",
+        "form_submit",
+        "reload",
+        "history",
+        "script",
+        "browser"
+      ]
+    },
+    "PageRefV2": {
       "description": "Page context dictionary entry — referenced by steps via `page` id.",
       "type": "object",
       "required": [
@@ -76,7 +70,24 @@
         }
       }
     },
-    "SelectedOption": {
+    "RecorderInfo": {
+      "type": "object",
+      "required": [
+        "bsk",
+        "vom"
+      ],
+      "properties": {
+        "bsk": {
+          "type": "string"
+        },
+        "vom": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        }
+      }
+    },
+    "SelectedOptionV2": {
       "description": "One selected option (`select` op).",
       "type": "object",
       "required": [
@@ -94,11 +105,53 @@
         }
       }
     },
-    "Step": {
-      "description": "One recorded user action — discriminated union by `op`.",
+    "SelectedOptionV3": {
+      "description": "One selected option (`select` op).",
+      "type": "object",
+      "required": [
+        "value"
+      ],
+      "properties": {
+        "label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    "StepEffectV2": {
+      "description": "Observed navigation after a step (objective fact only).",
+      "type": "object",
+      "required": [
+        "navigated_to"
+      ],
+      "properties": {
+        "navigated_to": {
+          "description": "Reference into `pages[]` for the destination page.",
+          "type": "string"
+        }
+      }
+    },
+    "StepResultV3": {
+      "type": "object",
+      "required": [
+        "state"
+      ],
+      "properties": {
+        "state": {
+          "type": "string"
+        }
+      }
+    },
+    "StepV2": {
+      "description": "One recorded user action — discriminated union by `op` (v2).",
       "oneOf": [
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -110,7 +163,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -138,7 +191,7 @@
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -150,7 +203,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -173,12 +226,12 @@
               "type": "string"
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -190,7 +243,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -213,12 +266,12 @@
               "type": "string"
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -231,7 +284,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -260,7 +313,7 @@
               ]
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             },
             "value": {
               "type": "string"
@@ -268,7 +321,7 @@
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -281,7 +334,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -306,16 +359,16 @@
             "selection": {
               "type": "array",
               "items": {
-                "$ref": "#/definitions/SelectedOption"
+                "$ref": "#/definitions/SelectedOptionV2"
               }
             },
             "target": {
-              "$ref": "#/definitions/TargetDescriptor"
+              "$ref": "#/definitions/TargetDescriptorV2"
             }
           }
         },
         {
-          "description": "Fields shared by every step variant (flattened in JSON).",
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
           "type": "object",
           "required": [
             "id",
@@ -327,7 +380,7 @@
             "effect": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/StepEffect"
+                  "$ref": "#/definitions/StepEffectV2"
                 },
                 {
                   "type": "null"
@@ -364,7 +417,7 @@
             "target": {
               "anyOf": [
                 {
-                  "$ref": "#/definitions/TargetDescriptor"
+                  "$ref": "#/definitions/TargetDescriptorV2"
                 },
                 {
                   "type": "null"
@@ -375,21 +428,294 @@
         }
       ]
     },
-    "StepEffect": {
-      "description": "Observed navigation after a step (objective fact only).",
-      "type": "object",
-      "required": [
-        "navigated_to"
-      ],
-      "properties": {
-        "navigated_to": {
-          "description": "Reference into `pages[]` for the destination page.",
-          "type": "string"
+    "StepV3": {
+      "description": "One recorded user action — discriminated union by `op`.",
+      "oneOf": [
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "cause",
+            "id",
+            "op",
+            "result",
+            "state",
+            "to"
+          ],
+          "properties": {
+            "cause": {
+              "$ref": "#/definitions/NavigationCause"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "navigate"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "to": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "click"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "hover"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "commit",
+            "id",
+            "op",
+            "result",
+            "state",
+            "target",
+            "value"
+          ],
+          "properties": {
+            "commit": {
+              "$ref": "#/definitions/FillCommit"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "fill"
+              ]
+            },
+            "redacted": {
+              "type": "boolean"
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            },
+            "value": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "select"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "selection": {
+              "type": "array",
+              "items": {
+                "$ref": "#/definitions/SelectedOptionV3"
+              }
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "key",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "key": {
+              "type": "string"
+            },
+            "modifiers": {
+              "type": [
+                "array",
+                "null"
+              ],
+              "items": {
+                "$ref": "#/definitions/KeyModifier"
+              }
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "press"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/TargetDescriptorV3"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "scroll"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            }
+          }
         }
-      }
+      ]
     },
-    "TargetDescriptor": {
-      "description": "Stable semantic handle for an interacted element.\n\n`name` and `nearby_label` are **untrusted page text**.",
+    "StopReason": {
+      "type": "string",
+      "enum": [
+        "user_finish",
+        "cli_stop"
+      ]
+    },
+    "TargetDescriptorV2": {
+      "description": "Stable semantic handle for an interacted element (v2).\n\n`name` and `nearby_label` are **untrusted page text**.",
       "type": "object",
       "required": [
         "tag"
@@ -430,8 +756,40 @@
         }
       }
     },
+    "TargetDescriptorV3": {
+      "description": "Stable semantic handle for an interacted element within a page observation.",
+      "type": "object",
+      "properties": {
+        "ctx": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "ref": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "role": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "unmatched": {
+          "type": "boolean"
+        }
+      }
+    },
     "TraceEntry": {
-      "description": "Recording entry point — first URL the flow starts from.",
       "type": "object",
       "required": [
         "start_url"
@@ -441,6 +799,143 @@
           "type": "string"
         }
       }
+    },
+    "TraceStateV3": {
+      "description": "Page observation dictionary entry — referenced by steps via `state` / `result.state`.",
+      "type": "object",
+      "required": [
+        "body",
+        "id",
+        "url"
+      ],
+      "properties": {
+        "body": {
+          "description": "Full page observation (front matter + VOM body + annotations).",
+          "type": "string"
+        },
+        "id": {
+          "type": "string"
+        },
+        "title": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "truncated": {
+          "type": "boolean"
+        },
+        "url": {
+          "type": "string"
+        }
+      }
+    },
+    "TraceV2": {
+      "title": "TraceV2",
+      "description": "Persisted user-action trace exported by legacy `tool.record_stop` / `await`.\n\nUnknown extension fields are ignored so older traces remain readable. `states[]` and a numeric `version` are reserved for Trace v3 / `RecordedTrace` classification.",
+      "type": "object",
+      "required": [
+        "entry",
+        "pages",
+        "recorded_at",
+        "steps"
+      ],
+      "properties": {
+        "entry": {
+          "$ref": "#/definitions/TraceEntry"
+        },
+        "pages": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/PageRefV2"
+          }
+        },
+        "purpose": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "recorded_at": {
+          "description": "RFC 3339 timestamp when recording stopped.",
+          "type": "string"
+        },
+        "started_at": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "states": false,
+        "steps": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/StepV2"
+          }
+        },
+        "version": {
+          "description": "Numeric version selects Trace v3. Legacy v2 envelopes omit this field.",
+          "not": {
+            "type": "integer"
+          }
+        }
+      }
+    },
+    "TraceV3": {
+      "description": "Wire trace returned by `tool.record_stop` / `await`.",
+      "type": "object",
+      "required": [
+        "entry",
+        "recorded_at",
+        "recorder",
+        "states",
+        "steps",
+        "stopped_by",
+        "version"
+      ],
+      "properties": {
+        "entry": {
+          "$ref": "#/definitions/TraceEntry"
+        },
+        "purpose": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "recorded_at": {
+          "type": "string"
+        },
+        "recorder": {
+          "$ref": "#/definitions/RecorderInfo"
+        },
+        "started_at": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "states": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/TraceStateV3"
+          }
+        },
+        "steps": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/StepV3"
+          }
+        },
+        "stopped_by": {
+          "$ref": "#/definitions/StopReason"
+        },
+        "version": {
+          "type": "integer",
+          "const": 3
+        }
+      },
+      "additionalProperties": false
     }
   }
 }

crates/bsk-protocol/schema/trace_step.json

@@ -1,286 +1,32 @@
 {
   "$schema": "http://json-schema.org/draft-07/schema#",
-  "title": "Step",
-  "description": "One recorded user action — discriminated union by `op`.",
-  "oneOf": [
-    {
-      "description": "Fields shared by every step variant (flattened in JSON).",
-      "type": "object",
-      "required": [
-        "id",
-        "op",
-        "page",
-        "to"
-      ],
-      "properties": {
-        "effect": {
-          "anyOf": [
-            {
-              "$ref": "#/definitions/StepEffect"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "id": {
-          "type": "integer",
-          "format": "uint32",
-          "minimum": 0.0
-        },
-        "op": {
-          "type": "string",
-          "enum": [
-            "navigate"
-          ]
-        },
-        "page": {
-          "description": "Reference into `pages[]`.",
-          "type": "string"
-        },
-        "to": {
-          "type": "string"
-        }
-      }
-    },
-    {
-      "description": "Fields shared by every step variant (flattened in JSON).",
-      "type": "object",
-      "required": [
-        "id",
-        "op",
-        "page",
-        "target"
-      ],
-      "properties": {
-        "effect": {
-          "anyOf": [
-            {
-              "$ref": "#/definitions/StepEffect"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "id": {
-          "type": "integer",
-          "format": "uint32",
-          "minimum": 0.0
-        },
-        "op": {
-          "type": "string",
-          "enum": [
-            "click"
-          ]
-        },
-        "page": {
-          "description": "Reference into `pages[]`.",
-          "type": "string"
-        },
-        "target": {
-          "$ref": "#/definitions/TargetDescriptor"
-        }
-      }
-    },
-    {
-      "description": "Fields shared by every step variant (flattened in JSON).",
-      "type": "object",
-      "required": [
-        "id",
-        "op",
-        "page",
-        "target"
-      ],
-      "properties": {
-        "effect": {
-          "anyOf": [
-            {
-              "$ref": "#/definitions/StepEffect"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "id": {
-          "type": "integer",
-          "format": "uint32",
-          "minimum": 0.0
-        },
-        "op": {
-          "type": "string",
-          "enum": [
-            "hover"
-          ]
-        },
-        "page": {
-          "description": "Reference into `pages[]`.",
-          "type": "string"
-        },
-        "target": {
-          "$ref": "#/definitions/TargetDescriptor"
-        }
-      }
-    },
-    {
-      "description": "Fields shared by every step variant (flattened in JSON).",
-      "type": "object",
-      "required": [
-        "id",
-        "op",
-        "page",
-        "target",
-        "value"
-      ],
-      "properties": {
-        "effect": {
-          "anyOf": [
-            {
-              "$ref": "#/definitions/StepEffect"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "id": {
-          "type": "integer",
-          "format": "uint32",
-          "minimum": 0.0
-        },
-        "op": {
-          "type": "string",
-          "enum": [
-            "fill"
-          ]
-        },
-        "page": {
-          "description": "Reference into `pages[]`.",
-          "type": "string"
-        },
-        "redacted": {
-          "type": [
-            "boolean",
-            "null"
-          ]
-        },
-        "target": {
-          "$ref": "#/definitions/TargetDescriptor"
-        },
-        "value": {
-          "type": "string"
-        }
-      }
-    },
-    {
-      "description": "Fields shared by every step variant (flattened in JSON).",
-      "type": "object",
-      "required": [
-        "id",
-        "op",
-        "page",
-        "selection",
-        "target"
-      ],
-      "properties": {
-        "effect": {
-          "anyOf": [
-            {
-              "$ref": "#/definitions/StepEffect"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "id": {
-          "type": "integer",
-          "format": "uint32",
-          "minimum": 0.0
-        },
-        "op": {
-          "type": "string",
-          "enum": [
-            "select"
-          ]
-        },
-        "page": {
-          "description": "Reference into `pages[]`.",
-          "type": "string"
-        },
-        "selection": {
-          "type": "array",
-          "items": {
-            "$ref": "#/definitions/SelectedOption"
-          }
-        },
-        "target": {
-          "$ref": "#/definitions/TargetDescriptor"
-        }
-      }
-    },
-    {
-      "description": "Fields shared by every step variant (flattened in JSON).",
-      "type": "object",
-      "required": [
-        "id",
-        "key",
-        "op",
-        "page"
-      ],
-      "properties": {
-        "effect": {
-          "anyOf": [
-            {
-              "$ref": "#/definitions/StepEffect"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "id": {
-          "type": "integer",
-          "format": "uint32",
-          "minimum": 0.0
-        },
-        "key": {
-          "type": "string"
-        },
-        "modifiers": {
-          "type": [
-            "array",
-            "null"
-          ],
-          "items": {
-            "$ref": "#/definitions/KeyModifier"
-          }
-        },
-        "op": {
-          "type": "string",
-          "enum": [
-            "press"
-          ]
-        },
-        "page": {
-          "description": "Reference into `pages[]`.",
-          "type": "string"
-        },
-        "target": {
-          "anyOf": [
-            {
-              "$ref": "#/definitions/TargetDescriptor"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        }
-      }
-    }
-  ],
+  "title": "RecordedStep",
+  "not": {
+    "required": [
+      "page",
+      "state"
+    ]
+  },
+  "if": {
+    "required": [
+      "state"
+    ]
+  },
+  "then": {
+    "$ref": "#/definitions/StepV3"
+  },
+  "else": {
+    "$ref": "#/definitions/StepV2"
+  },
   "definitions": {
+    "FillCommit": {
+      "type": "string",
+      "enum": [
+        "enter",
+        "suggestion",
+        "blur"
+      ]
+    },
     "KeyModifier": {
       "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
       "type": "string",
@@ -291,7 +37,19 @@
         "shift"
       ]
     },
-    "SelectedOption": {
+    "NavigationCause": {
+      "type": "string",
+      "enum": [
+        "user_typed",
+        "link",
+        "form_submit",
+        "reload",
+        "history",
+        "script",
+        "browser"
+      ]
+    },
+    "SelectedOptionV2": {
       "description": "One selected option (`select` op).",
       "type": "object",
       "required": [
@@ -309,7 +67,25 @@
         }
       }
     },
-    "StepEffect": {
+    "SelectedOptionV3": {
+      "description": "One selected option (`select` op).",
+      "type": "object",
+      "required": [
+        "value"
+      ],
+      "properties": {
+        "label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    "StepEffectV2": {
       "description": "Observed navigation after a step (objective fact only).",
       "type": "object",
       "required": [
@@ -322,8 +98,579 @@
         }
       }
     },
-    "TargetDescriptor": {
-      "description": "Stable semantic handle for an interacted element.\n\n`name` and `nearby_label` are **untrusted page text**.",
+    "StepResultV3": {
+      "type": "object",
+      "required": [
+        "state"
+      ],
+      "properties": {
+        "state": {
+          "type": "string"
+        }
+      }
+    },
+    "StepV2": {
+      "description": "One recorded user action — discriminated union by `op` (v2).",
+      "oneOf": [
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "to"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "navigate"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "to": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "target"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "click"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "target"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "hover"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "target",
+            "value"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "fill"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "redacted": {
+              "type": [
+                "boolean",
+                "null"
+              ]
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            },
+            "value": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "selection",
+            "target"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "select"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "selection": {
+              "type": "array",
+              "items": {
+                "$ref": "#/definitions/SelectedOptionV2"
+              }
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "key",
+            "op",
+            "page"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "key": {
+              "type": "string"
+            },
+            "modifiers": {
+              "type": [
+                "array",
+                "null"
+              ],
+              "items": {
+                "$ref": "#/definitions/KeyModifier"
+              }
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "press"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "target": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/TargetDescriptorV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            }
+          }
+        }
+      ]
+    },
+    "StepV3": {
+      "description": "One recorded user action — discriminated union by `op`.",
+      "oneOf": [
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "cause",
+            "id",
+            "op",
+            "result",
+            "state",
+            "to"
+          ],
+          "properties": {
+            "cause": {
+              "$ref": "#/definitions/NavigationCause"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "navigate"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "to": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "click"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "hover"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "commit",
+            "id",
+            "op",
+            "result",
+            "state",
+            "target",
+            "value"
+          ],
+          "properties": {
+            "commit": {
+              "$ref": "#/definitions/FillCommit"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "fill"
+              ]
+            },
+            "redacted": {
+              "type": "boolean"
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            },
+            "value": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "select"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "selection": {
+              "type": "array",
+              "items": {
+                "$ref": "#/definitions/SelectedOptionV3"
+              }
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "key",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "key": {
+              "type": "string"
+            },
+            "modifiers": {
+              "type": [
+                "array",
+                "null"
+              ],
+              "items": {
+                "$ref": "#/definitions/KeyModifier"
+              }
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "press"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/TargetDescriptorV3"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "scroll"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            }
+          }
+        }
+      ]
+    },
+    "TargetDescriptorV2": {
+      "description": "Stable semantic handle for an interacted element (v2).\n\n`name` and `nearby_label` are **untrusted page text**.",
       "type": "object",
       "required": [
         "tag"
@@ -363,6 +710,39 @@
           "type": "string"
         }
       }
+    },
+    "TargetDescriptorV3": {
+      "description": "Stable semantic handle for an interacted element within a page observation.",
+      "type": "object",
+      "properties": {
+        "ctx": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "ref": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "role": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "unmatched": {
+          "type": "boolean"
+        }
+      }
     }
   }
 }

crates/bsk-protocol/schema/trace_step_v2.json

@@ -0,0 +1,368 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "StepV2",
+  "description": "One recorded user action — discriminated union by `op` (v2).",
+  "oneOf": [
+    {
+      "description": "Fields shared by every v2 step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "page",
+        "to"
+      ],
+      "properties": {
+        "effect": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/StepEffectV2"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "navigate"
+          ]
+        },
+        "page": {
+          "description": "Reference into `pages[]`.",
+          "type": "string"
+        },
+        "to": {
+          "type": "string"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every v2 step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "page",
+        "target"
+      ],
+      "properties": {
+        "effect": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/StepEffectV2"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "click"
+          ]
+        },
+        "page": {
+          "description": "Reference into `pages[]`.",
+          "type": "string"
+        },
+        "target": {
+          "$ref": "#/definitions/TargetDescriptorV2"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every v2 step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "page",
+        "target"
+      ],
+      "properties": {
+        "effect": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/StepEffectV2"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "hover"
+          ]
+        },
+        "page": {
+          "description": "Reference into `pages[]`.",
+          "type": "string"
+        },
+        "target": {
+          "$ref": "#/definitions/TargetDescriptorV2"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every v2 step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "page",
+        "target",
+        "value"
+      ],
+      "properties": {
+        "effect": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/StepEffectV2"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "fill"
+          ]
+        },
+        "page": {
+          "description": "Reference into `pages[]`.",
+          "type": "string"
+        },
+        "redacted": {
+          "type": [
+            "boolean",
+            "null"
+          ]
+        },
+        "target": {
+          "$ref": "#/definitions/TargetDescriptorV2"
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every v2 step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "page",
+        "selection",
+        "target"
+      ],
+      "properties": {
+        "effect": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/StepEffectV2"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "select"
+          ]
+        },
+        "page": {
+          "description": "Reference into `pages[]`.",
+          "type": "string"
+        },
+        "selection": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/SelectedOptionV2"
+          }
+        },
+        "target": {
+          "$ref": "#/definitions/TargetDescriptorV2"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every v2 step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "key",
+        "op",
+        "page"
+      ],
+      "properties": {
+        "effect": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/StepEffectV2"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "key": {
+          "type": "string"
+        },
+        "modifiers": {
+          "type": [
+            "array",
+            "null"
+          ],
+          "items": {
+            "$ref": "#/definitions/KeyModifier"
+          }
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "press"
+          ]
+        },
+        "page": {
+          "description": "Reference into `pages[]`.",
+          "type": "string"
+        },
+        "target": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        }
+      }
+    }
+  ],
+  "definitions": {
+    "KeyModifier": {
+      "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
+      "type": "string",
+      "enum": [
+        "alt",
+        "ctrl",
+        "meta",
+        "shift"
+      ]
+    },
+    "SelectedOptionV2": {
+      "description": "One selected option (`select` op).",
+      "type": "object",
+      "required": [
+        "value"
+      ],
+      "properties": {
+        "label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    "StepEffectV2": {
+      "description": "Observed navigation after a step (objective fact only).",
+      "type": "object",
+      "required": [
+        "navigated_to"
+      ],
+      "properties": {
+        "navigated_to": {
+          "description": "Reference into `pages[]` for the destination page.",
+          "type": "string"
+        }
+      }
+    },
+    "TargetDescriptorV2": {
+      "description": "Stable semantic handle for an interacted element (v2).\n\n`name` and `nearby_label` are **untrusted page text**.",
+      "type": "object",
+      "required": [
+        "tag"
+      ],
+      "properties": {
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name_attr": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "nearby_label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "placeholder": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "role": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "tag": {
+          "type": "string"
+        }
+      }
+    }
+  }
+}

crates/bsk-protocol/schema/trace_step_v3.json

@@ -0,0 +1,375 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "StepV3",
+  "description": "One recorded user action — discriminated union by `op`.",
+  "oneOf": [
+    {
+      "description": "Fields shared by every step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "cause",
+        "id",
+        "op",
+        "result",
+        "state",
+        "to"
+      ],
+      "properties": {
+        "cause": {
+          "$ref": "#/definitions/NavigationCause"
+        },
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "navigate"
+          ]
+        },
+        "result": {
+          "$ref": "#/definitions/StepResultV3"
+        },
+        "state": {
+          "description": "Observation id immediately before this action.",
+          "type": "string"
+        },
+        "to": {
+          "type": "string"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "result",
+        "state",
+        "target"
+      ],
+      "properties": {
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "click"
+          ]
+        },
+        "result": {
+          "$ref": "#/definitions/StepResultV3"
+        },
+        "state": {
+          "description": "Observation id immediately before this action.",
+          "type": "string"
+        },
+        "target": {
+          "$ref": "#/definitions/TargetDescriptorV3"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "result",
+        "state",
+        "target"
+      ],
+      "properties": {
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "hover"
+          ]
+        },
+        "result": {
+          "$ref": "#/definitions/StepResultV3"
+        },
+        "state": {
+          "description": "Observation id immediately before this action.",
+          "type": "string"
+        },
+        "target": {
+          "$ref": "#/definitions/TargetDescriptorV3"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "commit",
+        "id",
+        "op",
+        "result",
+        "state",
+        "target",
+        "value"
+      ],
+      "properties": {
+        "commit": {
+          "$ref": "#/definitions/FillCommit"
+        },
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "fill"
+          ]
+        },
+        "redacted": {
+          "type": "boolean"
+        },
+        "result": {
+          "$ref": "#/definitions/StepResultV3"
+        },
+        "state": {
+          "description": "Observation id immediately before this action.",
+          "type": "string"
+        },
+        "target": {
+          "$ref": "#/definitions/TargetDescriptorV3"
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "result",
+        "state",
+        "target"
+      ],
+      "properties": {
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "select"
+          ]
+        },
+        "result": {
+          "$ref": "#/definitions/StepResultV3"
+        },
+        "selection": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/SelectedOptionV3"
+          }
+        },
+        "state": {
+          "description": "Observation id immediately before this action.",
+          "type": "string"
+        },
+        "target": {
+          "$ref": "#/definitions/TargetDescriptorV3"
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "key",
+        "op",
+        "result",
+        "state"
+      ],
+      "properties": {
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "key": {
+          "type": "string"
+        },
+        "modifiers": {
+          "type": [
+            "array",
+            "null"
+          ],
+          "items": {
+            "$ref": "#/definitions/KeyModifier"
+          }
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "press"
+          ]
+        },
+        "result": {
+          "$ref": "#/definitions/StepResultV3"
+        },
+        "state": {
+          "description": "Observation id immediately before this action.",
+          "type": "string"
+        },
+        "target": {
+          "anyOf": [
+            {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        }
+      }
+    },
+    {
+      "description": "Fields shared by every step variant (flattened in JSON).",
+      "type": "object",
+      "required": [
+        "id",
+        "op",
+        "result",
+        "state"
+      ],
+      "properties": {
+        "id": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        },
+        "op": {
+          "type": "string",
+          "enum": [
+            "scroll"
+          ]
+        },
+        "result": {
+          "$ref": "#/definitions/StepResultV3"
+        },
+        "state": {
+          "description": "Observation id immediately before this action.",
+          "type": "string"
+        }
+      }
+    }
+  ],
+  "definitions": {
+    "FillCommit": {
+      "type": "string",
+      "enum": [
+        "enter",
+        "suggestion",
+        "blur"
+      ]
+    },
+    "KeyModifier": {
+      "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
+      "type": "string",
+      "enum": [
+        "alt",
+        "ctrl",
+        "meta",
+        "shift"
+      ]
+    },
+    "NavigationCause": {
+      "type": "string",
+      "enum": [
+        "user_typed",
+        "link",
+        "form_submit",
+        "reload",
+        "history",
+        "script",
+        "browser"
+      ]
+    },
+    "SelectedOptionV3": {
+      "description": "One selected option (`select` op).",
+      "type": "object",
+      "required": [
+        "value"
+      ],
+      "properties": {
+        "label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    "StepResultV3": {
+      "type": "object",
+      "required": [
+        "state"
+      ],
+      "properties": {
+        "state": {
+          "type": "string"
+        }
+      }
+    },
+    "TargetDescriptorV3": {
+      "description": "Stable semantic handle for an interacted element within a page observation.",
+      "type": "object",
+      "properties": {
+        "ctx": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "ref": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "role": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "unmatched": {
+          "type": "boolean"
+        }
+      }
+    }
+  }
+}

crates/bsk-protocol/schema/trace_v2.json

@@ -0,0 +1,451 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "TraceV2",
+  "description": "Persisted user-action trace exported by legacy `tool.record_stop` / `await`.\n\nUnknown extension fields are ignored so older traces remain readable. `states[]` and a numeric `version` are reserved for Trace v3 / `RecordedTrace` classification.",
+  "type": "object",
+  "required": [
+    "entry",
+    "pages",
+    "recorded_at",
+    "steps"
+  ],
+  "properties": {
+    "entry": {
+      "$ref": "#/definitions/TraceEntry"
+    },
+    "pages": {
+      "type": "array",
+      "items": {
+        "$ref": "#/definitions/PageRefV2"
+      }
+    },
+    "purpose": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "recorded_at": {
+      "description": "RFC 3339 timestamp when recording stopped.",
+      "type": "string"
+    },
+    "started_at": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "states": false,
+    "steps": {
+      "type": "array",
+      "items": {
+        "$ref": "#/definitions/StepV2"
+      }
+    },
+    "version": {
+      "description": "Numeric version selects Trace v3. Legacy v2 envelopes omit this field.",
+      "not": {
+        "type": "integer"
+      }
+    }
+  },
+  "definitions": {
+    "KeyModifier": {
+      "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
+      "type": "string",
+      "enum": [
+        "alt",
+        "ctrl",
+        "meta",
+        "shift"
+      ]
+    },
+    "PageRefV2": {
+      "description": "Page context dictionary entry — referenced by steps via `page` id.",
+      "type": "object",
+      "required": [
+        "id",
+        "url"
+      ],
+      "properties": {
+        "id": {
+          "type": "string"
+        },
+        "title": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "url": {
+          "type": "string"
+        }
+      }
+    },
+    "SelectedOptionV2": {
+      "description": "One selected option (`select` op).",
+      "type": "object",
+      "required": [
+        "value"
+      ],
+      "properties": {
+        "label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    "StepEffectV2": {
+      "description": "Observed navigation after a step (objective fact only).",
+      "type": "object",
+      "required": [
+        "navigated_to"
+      ],
+      "properties": {
+        "navigated_to": {
+          "description": "Reference into `pages[]` for the destination page.",
+          "type": "string"
+        }
+      }
+    },
+    "StepV2": {
+      "description": "One recorded user action — discriminated union by `op` (v2).",
+      "oneOf": [
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "to"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "navigate"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "to": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "target"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "click"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "target"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "hover"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "target",
+            "value"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "fill"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "redacted": {
+              "type": [
+                "boolean",
+                "null"
+              ]
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            },
+            "value": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "page",
+            "selection",
+            "target"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "select"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "selection": {
+              "type": "array",
+              "items": {
+                "$ref": "#/definitions/SelectedOptionV2"
+              }
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV2"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every v2 step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "key",
+            "op",
+            "page"
+          ],
+          "properties": {
+            "effect": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/StepEffectV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "key": {
+              "type": "string"
+            },
+            "modifiers": {
+              "type": [
+                "array",
+                "null"
+              ],
+              "items": {
+                "$ref": "#/definitions/KeyModifier"
+              }
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "press"
+              ]
+            },
+            "page": {
+              "description": "Reference into `pages[]`.",
+              "type": "string"
+            },
+            "target": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/TargetDescriptorV2"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            }
+          }
+        }
+      ]
+    },
+    "TargetDescriptorV2": {
+      "description": "Stable semantic handle for an interacted element (v2).\n\n`name` and `nearby_label` are **untrusted page text**.",
+      "type": "object",
+      "required": [
+        "tag"
+      ],
+      "properties": {
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name_attr": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "nearby_label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "placeholder": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "role": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "tag": {
+          "type": "string"
+        }
+      }
+    },
+    "TraceEntry": {
+      "type": "object",
+      "required": [
+        "start_url"
+      ],
+      "properties": {
+        "start_url": {
+          "type": "string"
+        }
+      }
+    }
+  }
+}

crates/bsk-protocol/schema/trace_v3.json

@@ -0,0 +1,496 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "TraceV3",
+  "description": "Wire trace returned by `tool.record_stop` / `await`.",
+  "type": "object",
+  "required": [
+    "entry",
+    "recorded_at",
+    "recorder",
+    "states",
+    "steps",
+    "stopped_by",
+    "version"
+  ],
+  "properties": {
+    "entry": {
+      "$ref": "#/definitions/TraceEntry"
+    },
+    "purpose": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "recorded_at": {
+      "type": "string"
+    },
+    "recorder": {
+      "$ref": "#/definitions/RecorderInfo"
+    },
+    "started_at": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "states": {
+      "type": "array",
+      "items": {
+        "$ref": "#/definitions/TraceStateV3"
+      }
+    },
+    "steps": {
+      "type": "array",
+      "items": {
+        "$ref": "#/definitions/StepV3"
+      }
+    },
+    "stopped_by": {
+      "$ref": "#/definitions/StopReason"
+    },
+    "version": {
+      "type": "integer",
+      "const": 3
+    }
+  },
+  "additionalProperties": false,
+  "definitions": {
+    "FillCommit": {
+      "type": "string",
+      "enum": [
+        "enter",
+        "suggestion",
+        "blur"
+      ]
+    },
+    "KeyModifier": {
+      "description": "Keyboard modifier flags. Multiple flags may be combined; the extension folds them into CDP's bitfield (`alt=1, ctrl=2, meta=4, shift=8`).",
+      "type": "string",
+      "enum": [
+        "alt",
+        "ctrl",
+        "meta",
+        "shift"
+      ]
+    },
+    "NavigationCause": {
+      "type": "string",
+      "enum": [
+        "user_typed",
+        "link",
+        "form_submit",
+        "reload",
+        "history",
+        "script",
+        "browser"
+      ]
+    },
+    "RecorderInfo": {
+      "type": "object",
+      "required": [
+        "bsk",
+        "vom"
+      ],
+      "properties": {
+        "bsk": {
+          "type": "string"
+        },
+        "vom": {
+          "type": "integer",
+          "format": "uint32",
+          "minimum": 0.0
+        }
+      }
+    },
+    "SelectedOptionV3": {
+      "description": "One selected option (`select` op).",
+      "type": "object",
+      "required": [
+        "value"
+      ],
+      "properties": {
+        "label": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "value": {
+          "type": "string"
+        }
+      }
+    },
+    "StepResultV3": {
+      "type": "object",
+      "required": [
+        "state"
+      ],
+      "properties": {
+        "state": {
+          "type": "string"
+        }
+      }
+    },
+    "StepV3": {
+      "description": "One recorded user action — discriminated union by `op`.",
+      "oneOf": [
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "cause",
+            "id",
+            "op",
+            "result",
+            "state",
+            "to"
+          ],
+          "properties": {
+            "cause": {
+              "$ref": "#/definitions/NavigationCause"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "navigate"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "to": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "click"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "hover"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "commit",
+            "id",
+            "op",
+            "result",
+            "state",
+            "target",
+            "value"
+          ],
+          "properties": {
+            "commit": {
+              "$ref": "#/definitions/FillCommit"
+            },
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "fill"
+              ]
+            },
+            "redacted": {
+              "type": "boolean"
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            },
+            "value": {
+              "type": "string"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state",
+            "target"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "select"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "selection": {
+              "type": "array",
+              "items": {
+                "$ref": "#/definitions/SelectedOptionV3"
+              }
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "$ref": "#/definitions/TargetDescriptorV3"
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "key",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "key": {
+              "type": "string"
+            },
+            "modifiers": {
+              "type": [
+                "array",
+                "null"
+              ],
+              "items": {
+                "$ref": "#/definitions/KeyModifier"
+              }
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "press"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            },
+            "target": {
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/TargetDescriptorV3"
+                },
+                {
+                  "type": "null"
+                }
+              ]
+            }
+          }
+        },
+        {
+          "description": "Fields shared by every step variant (flattened in JSON).",
+          "type": "object",
+          "required": [
+            "id",
+            "op",
+            "result",
+            "state"
+          ],
+          "properties": {
+            "id": {
+              "type": "integer",
+              "format": "uint32",
+              "minimum": 0.0
+            },
+            "op": {
+              "type": "string",
+              "enum": [
+                "scroll"
+              ]
+            },
+            "result": {
+              "$ref": "#/definitions/StepResultV3"
+            },
+            "state": {
+              "description": "Observation id immediately before this action.",
+              "type": "string"
+            }
+          }
+        }
+      ]
+    },
+    "StopReason": {
+      "type": "string",
+      "enum": [
+        "user_finish",
+        "cli_stop"
+      ]
+    },
+    "TargetDescriptorV3": {
+      "description": "Stable semantic handle for an interacted element within a page observation.",
+      "type": "object",
+      "properties": {
+        "ctx": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "ref": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "role": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "unmatched": {
+          "type": "boolean"
+        }
+      }
+    },
+    "TraceEntry": {
+      "type": "object",
+      "required": [
+        "start_url"
+      ],
+      "properties": {
+        "start_url": {
+          "type": "string"
+        }
+      }
+    },
+    "TraceStateV3": {
+      "description": "Page observation dictionary entry — referenced by steps via `state` / `result.state`.",
+      "type": "object",
+      "required": [
+        "body",
+        "id",
+        "url"
+      ],
+      "properties": {
+        "body": {
+          "description": "Full page observation (front matter + VOM body + annotations).",
+          "type": "string"
+        },
+        "id": {
+          "type": "string"
+        },
+        "title": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "truncated": {
+          "type": "boolean"
+        },
+        "url": {
+          "type": "string"
+        }
+      }
+    }
+  }
+}

crates/bsk-protocol/src/bin/dump-schema.rs

@@ -113,8 +113,12 @@ fn main() {
     dump!(RequestHelpParams, "tool_request_help_params");
     dump!(RequestHelpResult, "tool_request_help_result");
 
-    dump!(Trace, "trace");
-    dump!(Step, "trace_step");
+    dump!(TraceV2, "trace_v2");
+    dump!(TraceV3, "trace_v3");
+    dump!(RecordedTrace, "trace");
+    dump!(StepV2, "trace_step_v2");
+    dump!(StepV3, "trace_step_v3");
+    dump!(RecordedStep, "trace_step");
     dump!(RecordStartParams, "tool_record_start_params");
     dump!(RecordStartResult, "tool_record_start_result");
     dump!(RecordStopParams, "tool_record_stop_params");

crates/bsk-protocol/src/tools/mod.rs

@@ -9,6 +9,9 @@ pub mod navigation;
 pub mod network;
 pub mod observation;
 pub mod record;
+mod record_common;
+mod record_v2;
+mod record_v3;
 pub mod script;
 pub mod session;
 pub mod tabs;

crates/bsk-protocol/src/tools/record.rs

@@ -1,147 +1,23 @@
 //! Semantic user-action recording (`tool.record_start` / `stop` / `await`).
 //!
-//! Trace v2 is a **record-only** log of user actions: what was clicked, filled,
-//! selected, and where navigation occurred. No LLM runs during recording, so
-//! variable-vs-constant classification is **not** stored — executing agents
-//! infer that at run time from raw values and control names.
+//! Wire traces are either Trace v2 (`pages[]`) or Trace v3 (`version: 3`,
+//! `states[]`). Version-specific models live in `record_v2` / `record_v3`.
 
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
-use super::interaction::KeyModifier;
+pub use super::record_common::TraceEntry;
+pub use super::record_v2::{
+    PageRefV2, SelectedOptionV2, StepCommonV2, StepEffectV2, StepV2, TargetDescriptorV2, TraceV2,
+};
+pub use super::record_v3::{
+    FillCommit, NavigationCause, RecorderInfo, SelectedOptionV3, StepCommonV3, StepResultV3,
+    StepV3, StopReason, TRACE_VERSION_V3, TargetDescriptorV3, TraceStateV3, TraceV3,
+    VOM_FORMAT_VERSION,
+};
 
-// ---------------------------------------------------------------------------
-// Target
-// ---------------------------------------------------------------------------
-
-/// Stable semantic handle for an interacted element.
-///
-/// `name` and `nearby_label` are **untrusted page text**.
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
-pub struct TargetDescriptor {
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub role: Option<String>,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub name: Option<String>,
-    pub tag: String,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub name_attr: Option<String>,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub placeholder: Option<String>,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub nearby_label: Option<String>,
-}
-
-// ---------------------------------------------------------------------------
-// Trace envelope
-// ---------------------------------------------------------------------------
-
-/// Recording entry point — first URL the flow starts from.
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
-pub struct TraceEntry {
-    pub start_url: String,
-}
-
-/// Page context dictionary entry — referenced by steps via `page` id.
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
-pub struct PageRef {
-    pub id: String,
-    pub url: String,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub title: Option<String>,
-}
-
-/// One selected option (`select` op).
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
-pub struct SelectedOption {
-    pub value: String,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub label: Option<String>,
-}
-
-/// Observed navigation after a step (objective fact only).
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
-pub struct StepEffect {
-    /// Reference into `pages[]` for the destination page.
-    pub navigated_to: String,
-}
-
-/// Fields shared by every step variant (flattened in JSON).
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
-pub struct StepCommon {
-    pub id: u32,
-    /// Reference into `pages[]`.
-    pub page: String,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub effect: Option<StepEffect>,
-}
-
-// ---------------------------------------------------------------------------
-// Step op-specific payloads
-// ---------------------------------------------------------------------------
-
-/// One recorded user action — discriminated union by `op`.
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
-#[serde(tag = "op", rename_all = "snake_case")]
-pub enum Step {
-    Navigate {
-        #[serde(flatten)]
-        common: StepCommon,
-        to: String,
-    },
-    Click {
-        #[serde(flatten)]
-        common: StepCommon,
-        target: TargetDescriptor,
-    },
-    Hover {
-        #[serde(flatten)]
-        common: StepCommon,
-        target: TargetDescriptor,
-    },
-    Fill {
-        #[serde(flatten)]
-        common: StepCommon,
-        target: TargetDescriptor,
-        value: String,
-        #[serde(default, skip_serializing_if = "Option::is_none")]
-        redacted: Option<bool>,
-    },
-    Select {
-        #[serde(flatten)]
-        common: StepCommon,
-        target: TargetDescriptor,
-        selection: Vec<SelectedOption>,
-    },
-    Press {
-        #[serde(flatten)]
-        common: StepCommon,
-        key: String,
-        #[serde(default, skip_serializing_if = "Option::is_none")]
-        modifiers: Option<Vec<KeyModifier>>,
-        #[serde(default, skip_serializing_if = "Option::is_none")]
-        target: Option<TargetDescriptor>,
-    },
-}
-
-// ---------------------------------------------------------------------------
-// Trace root
-// ---------------------------------------------------------------------------
-
-/// Persisted user-action trace exported by `tool.record_stop` / `await`.
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
-pub struct Trace {
-    /// RFC 3339 timestamp when recording stopped.
-    pub recorded_at: String,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub started_at: Option<String>,
-    /// Optional user-provided goal from `--purpose` (metadata only).
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub purpose: Option<String>,
-    pub entry: TraceEntry,
-    pub pages: Vec<PageRef>,
-    pub steps: Vec<Step>,
-}
+/// Logical v2 identifier. Not a wire field — v2 envelopes omit `version`.
+pub const TRACE_VERSION_V2: u32 = 2;
 
 // ---------------------------------------------------------------------------
 // RPC params / results
@@ -169,9 +45,209 @@ pub struct RecordStopParams {
     pub session_id: String,
 }
 
+/// Wire trace payload — v2 (legacy `pages[]`) or v3 (`version: 3`, `states[]`).
+///
+/// Classification matches [`RecordedTrace::classify_value`]: a numeric `version`
+/// selects v3 (and forbids `pages[]`); otherwise the envelope is v2 and must
+/// not include `states[]`.
+#[derive(Debug, Clone, PartialEq)]
+pub enum RecordedTrace {
+    V2(TraceV2),
+    V3(TraceV3),
+}
+
+impl RecordedTrace {
+    pub fn classify_value(v: &serde_json::Value) -> Result<Self, String> {
+        if let Some(ver) = v.get("version").and_then(|x| x.as_u64()) {
+            if ver != u64::from(TRACE_VERSION_V3) {
+                return Err(format!("unsupported trace version {ver}"));
+            }
+            if v.get("pages").is_some() {
+                return Err("trace v3 must not include legacy pages[]".into());
+            }
+            return serde_json::from_value(v.clone())
+                .map(RecordedTrace::V3)
+                .map_err(|e| e.to_string());
+        }
+        if v.get("states").is_some() {
+            return Err("trace v2 must not include states[]; set version: 3 for Trace v3".into());
+        }
+        if v.get("pages").is_some() {
+            return serde_json::from_value(v.clone())
+                .map(RecordedTrace::V2)
+                .map_err(|e| e.to_string());
+        }
+        Err("ambiguous or unparseable trace".into())
+    }
+}
+
+impl Serialize for RecordedTrace {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        match self {
+            RecordedTrace::V2(t) => t.serialize(serializer),
+            RecordedTrace::V3(t) => t.serialize(serializer),
+        }
+    }
+}
+
+impl<'de> Deserialize<'de> for RecordedTrace {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let value = serde_json::Value::deserialize(deserializer)?;
+        Self::classify_value(&value).map_err(serde::de::Error::custom)
+    }
+}
+
+impl JsonSchema for RecordedTrace {
+    fn schema_name() -> String {
+        "RecordedTrace".into()
+    }
+
+    fn json_schema(generator: &mut schemars::SchemaGenerator) -> schemars::schema::Schema {
+        // Mirror classify_value: a numeric `version` selects v3; otherwise v2.
+        // TraceV2 stays open for unknown extension fields but forbids `states[]`
+        // and a numeric `version`. TraceV3 already denies `pages[]`.
+        let mut version_props = schemars::Map::new();
+        version_props.insert(
+            "version".into(),
+            schemars::schema::SchemaObject {
+                instance_type: Some(schemars::schema::InstanceType::Integer.into()),
+                ..Default::default()
+            }
+            .into(),
+        );
+        let mut required = schemars::Set::new();
+        required.insert("version".into());
+
+        schemars::schema::SchemaObject {
+            subschemas: Some(Box::new(schemars::schema::SubschemaValidation {
+                if_schema: Some(Box::new(
+                    schemars::schema::SchemaObject {
+                        object: Some(Box::new(schemars::schema::ObjectValidation {
+                            properties: version_props,
+                            required,
+                            ..Default::default()
+                        })),
+                        ..Default::default()
+                    }
+                    .into(),
+                )),
+                then_schema: Some(Box::new(generator.subschema_for::<TraceV3>())),
+                else_schema: Some(Box::new(generator.subschema_for::<TraceV2>())),
+                ..Default::default()
+            })),
+            ..Default::default()
+        }
+        .into()
+    }
+}
+
+/// One recorded step — v2 (`page`) or v3 (`state` / `result.state`).
+///
+/// Classification matches [`RecordedStep::classify_value`]: `state` selects v3
+/// (and forbids `page`); otherwise the step is v2 and must include `page`.
+#[derive(Debug, Clone, PartialEq)]
+pub enum RecordedStep {
+    V2(StepV2),
+    V3(StepV3),
+}
+
+impl RecordedStep {
+    pub fn classify_value(v: &serde_json::Value) -> Result<Self, String> {
+        if v.get("state").is_some() {
+            if v.get("page").is_some() {
+                return Err("step v3 must not include legacy page".into());
+            }
+            return serde_json::from_value(v.clone())
+                .map(RecordedStep::V3)
+                .map_err(|e| e.to_string());
+        }
+        if v.get("page").is_some() {
+            return serde_json::from_value(v.clone())
+                .map(RecordedStep::V2)
+                .map_err(|e| e.to_string());
+        }
+        Err("ambiguous or unparseable step".into())
+    }
+}
+
+impl Serialize for RecordedStep {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        match self {
+            RecordedStep::V2(s) => s.serialize(serializer),
+            RecordedStep::V3(s) => s.serialize(serializer),
+        }
+    }
+}
+
+impl<'de> Deserialize<'de> for RecordedStep {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let value = serde_json::Value::deserialize(deserializer)?;
+        Self::classify_value(&value).map_err(serde::de::Error::custom)
+    }
+}
+
+impl JsonSchema for RecordedStep {
+    fn schema_name() -> String {
+        "RecordedStep".into()
+    }
+
+    fn json_schema(generator: &mut schemars::SchemaGenerator) -> schemars::schema::Schema {
+        // Mirror classify_value: `state` selects v3; otherwise v2.
+        // Mixed page + state is rejected at this layer because StepV2/StepV3
+        // still allow unknown extension fields.
+        let mut required = schemars::Set::new();
+        required.insert("state".into());
+        let mut mixed_keys = schemars::Set::new();
+        mixed_keys.insert("page".into());
+        mixed_keys.insert("state".into());
+
+        schemars::schema::SchemaObject {
+            subschemas: Some(Box::new(schemars::schema::SubschemaValidation {
+                if_schema: Some(Box::new(
+                    schemars::schema::SchemaObject {
+                        object: Some(Box::new(schemars::schema::ObjectValidation {
+                            required,
+                            ..Default::default()
+                        })),
+                        ..Default::default()
+                    }
+                    .into(),
+                )),
+                then_schema: Some(Box::new(generator.subschema_for::<StepV3>())),
+                else_schema: Some(Box::new(generator.subschema_for::<StepV2>())),
+                not: Some(Box::new(
+                    schemars::schema::SchemaObject {
+                        object: Some(Box::new(schemars::schema::ObjectValidation {
+                            required: mixed_keys,
+                            ..Default::default()
+                        })),
+                        ..Default::default()
+                    }
+                    .into(),
+                )),
+                ..Default::default()
+            })),
+            ..Default::default()
+        }
+        .into()
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
 pub struct RecordStopResult {
-    pub trace: Trace,
+    pub trace: RecordedTrace,
 }
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
@@ -183,281 +259,197 @@ pub struct RecordAwaitParams {
 
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
 pub struct RecordAwaitResult {
-    pub trace: Trace,
+    pub trace: RecordedTrace,
 }
 
-// ---------------------------------------------------------------------------
-// Tests
-// ---------------------------------------------------------------------------
-
 #[cfg(test)]
 mod tests {
     use super::*;
     use serde_json::json;
 
-    fn sample_common(id: u32) -> StepCommon {
-        StepCommon {
-            id,
-            page: "p1".into(),
-            effect: None,
+    #[test]
+    fn recorded_trace_classifies_v2_and_v3() {
+        let v2 = json!({
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "entry": { "start_url": "https://example.com/" },
+            "pages": [{ "id": "p1", "url": "https://example.com/" }],
+            "steps": []
+        });
+        match RecordedTrace::classify_value(&v2).unwrap() {
+            RecordedTrace::V2(_) => {}
+            other => panic!("expected v2, got {other:?}"),
         }
-    }
 
-    fn sample_target() -> TargetDescriptor {
-        TargetDescriptor {
-            role: Some("button".into()),
-            name: Some("发布".into()),
-            tag: "button".into(),
-            name_attr: None,
-            placeholder: None,
-            nearby_label: None,
-        }
-    }
-
-    fn sample_trace() -> Trace {
-        Trace {
-            recorded_at: "2026-07-17T09:01:10Z".into(),
-            started_at: Some("2026-07-17T09:00:00Z".into()),
-            purpose: Some("发布一篇文章".into()),
-            entry: TraceEntry {
-                start_url: "https://x.com/editor".into(),
-            },
-            pages: vec![
-                PageRef {
-                    id: "p1".into(),
-                    url: "https://x.com/editor".into(),
-                    title: Some("写文章".into()),
-                },
-                PageRef {
-                    id: "p2".into(),
-                    url: "https://x.com/p/99".into(),
-                    title: None,
-                },
-            ],
-            steps: vec![
-                Step::Fill {
-                    common: sample_common(1),
-                    target: TargetDescriptor {
-                        role: Some("textbox".into()),
-                        name: Some("标题".into()),
-                        tag: "input".into(),
-                        name_attr: None,
-                        placeholder: None,
-                        nearby_label: None,
-                    },
-                    value: "我的第一篇文章".into(),
-                    redacted: None,
-                },
-                Step::Select {
-                    common: sample_common(3),
-                    target: TargetDescriptor {
-                        role: Some("combobox".into()),
-                        name: Some("分类".into()),
-                        tag: "select".into(),
-                        name_attr: None,
-                        placeholder: None,
-                        nearby_label: None,
-                    },
-                    selection: vec![SelectedOption {
-                        value: "tech".into(),
-                        label: Some("技术分享".into()),
-                    }],
-                },
-                Step::Click {
-                    common: StepCommon {
-                        effect: Some(StepEffect {
-                            navigated_to: "p2".into(),
-                        }),
-                        ..sample_common(4)
-                    },
-                    target: sample_target(),
-                },
-            ],
+        let v3 = json!({
+            "version": 3,
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "stopped_by": "user_finish",
+            "entry": { "start_url": "https://example.com/" },
+            "recorder": { "bsk": "0.1.10", "vom": 1 },
+            "states": [],
+            "steps": []
+        });
+        match RecordedTrace::classify_value(&v3).unwrap() {
+            RecordedTrace::V3(t) => assert_eq!(t.version, 3),
+            other => panic!("expected v3, got {other:?}"),
         }
     }
 
     #[test]
-    fn step_click_round_trips() {
-        let step = Step::Click {
-            common: sample_common(1),
-            target: sample_target(),
-        };
-        let v = serde_json::to_value(&step).unwrap();
-        assert_eq!(v.get("op").and_then(|v| v.as_str()), Some("click"));
-        assert_eq!(v.get("page").and_then(|v| v.as_str()), Some("p1"));
-        assert!(v.get("key").is_none());
-        let round: Step = serde_json::from_value(v).unwrap();
-        assert_eq!(round, step);
+    fn recorded_trace_rejects_mixed_and_unsupported_versions() {
+        let v2_with_states = json!({
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "entry": { "start_url": "https://example.com/" },
+            "pages": [{ "id": "p1", "url": "https://example.com/" }],
+            "states": [],
+            "steps": []
+        });
+        assert!(RecordedTrace::classify_value(&v2_with_states).is_err());
+
+        let v3_with_pages = json!({
+            "version": 3,
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "stopped_by": "user_finish",
+            "entry": { "start_url": "https://example.com/" },
+            "recorder": { "bsk": "0.1.10", "vom": 1 },
+            "pages": [{ "id": "p1", "url": "https://example.com/" }],
+            "states": [],
+            "steps": []
+        });
+        assert!(RecordedTrace::classify_value(&v3_with_pages).is_err());
+
+        let unsupported = json!({
+            "version": 2,
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "stopped_by": "user_finish",
+            "entry": { "start_url": "https://example.com/" },
+            "recorder": { "bsk": "0.1.10", "vom": 1 },
+            "states": [],
+            "steps": []
+        });
+        assert!(RecordedTrace::classify_value(&unsupported).is_err());
+        assert!(serde_json::from_value::<TraceV3>(unsupported).is_err());
     }
 
-    #[test]
-    fn step_fill_with_raw_value_round_trips() {
-        let step = Step::Fill {
-            common: sample_common(2),
-            target: TargetDescriptor {
-                role: Some("textbox".into()),
-                name: Some("服务名称".into()),
-                tag: "input".into(),
-                name_attr: Some("serviceName".into()),
-                placeholder: None,
-                nearby_label: None,
-            },
-            value: "my-svc".into(),
-            redacted: None,
-        };
-        let v = serde_json::to_value(&step).unwrap();
-        assert_eq!(v["op"], "fill");
-        assert_eq!(v["value"], "my-svc");
-        let round: Step = serde_json::from_value(v).unwrap();
-        assert_eq!(round, step);
-    }
-
-    #[test]
-    fn step_fill_password_is_redacted() {
-        let step = Step::Fill {
-            common: sample_common(1),
-            target: TargetDescriptor {
-                role: Some("textbox".into()),
-                name: Some("密码".into()),
-                tag: "input".into(),
-                name_attr: None,
-                placeholder: None,
-                nearby_label: None,
-            },
-            value: "***".into(),
-            redacted: Some(true),
-        };
-        let v = serde_json::to_value(&step).unwrap();
-        assert_eq!(v["value"], "***");
-        assert_eq!(v["redacted"], true);
-    }
-
-    #[test]
-    fn step_select_uses_object_array() {
-        let step = Step::Select {
-            common: sample_common(3),
-            target: TargetDescriptor {
-                role: Some("combobox".into()),
-                name: Some("分类".into()),
-                tag: "select".into(),
-                name_attr: None,
-                placeholder: None,
-                nearby_label: None,
-            },
-            selection: vec![SelectedOption {
-                value: "tech".into(),
-                label: Some("技术分享".into()),
-            }],
-        };
-        let v = serde_json::to_value(&step).unwrap();
-        assert_eq!(v["selection"][0]["value"], "tech");
-        assert_eq!(v["selection"][0]["label"], "技术分享");
-        let round: Step = serde_json::from_value(v).unwrap();
-        assert_eq!(round, step);
-    }
-
-    #[test]
-    fn step_navigate_round_trips() {
-        let step = Step::Navigate {
-            common: sample_common(1),
-            to: "https://example.com".into(),
-        };
-        let v = serde_json::to_value(&step).unwrap();
-        assert_eq!(v["op"], "navigate");
-        assert_eq!(v["to"], "https://example.com");
-        let round: Step = serde_json::from_value(v).unwrap();
-        assert_eq!(round, step);
-    }
-
-    #[test]
-    fn step_press_with_modifiers_round_trips() {
-        let step = Step::Press {
-            common: StepCommon {
-                effect: Some(StepEffect {
-                    navigated_to: "p2".into(),
-                }),
-                ..sample_common(2)
-            },
-            key: "Enter".into(),
-            modifiers: Some(vec![KeyModifier::Ctrl, KeyModifier::Shift]),
-            target: Some(sample_target()),
-        };
-        let v = serde_json::to_value(&step).unwrap();
-        assert_eq!(v["key"], "Enter");
-        assert_eq!(v["modifiers"], json!(["ctrl", "shift"]));
-        assert_eq!(v["effect"]["navigated_to"], "p2");
-        let round: Step = serde_json::from_value(v).unwrap();
-        assert_eq!(round, step);
-    }
-
-    #[test]
-    fn trace_record_only_round_trips() {
-        let trace = sample_trace();
-        let v = serde_json::to_value(&trace).unwrap();
-        assert!(v.get("version").is_none());
+    fn assert_classifies_by_integer_version(schema: &serde_json::Value) {
         assert_eq!(
-            v.get("purpose").and_then(|v| v.as_str()),
-            Some("发布一篇文章")
+            schema["if"]["required"],
+            json!(["version"]),
+            "numeric version is the RecordedTrace classification key"
         );
-        assert!(v.get("parameters").is_none());
-        assert!(v.get("site").is_none());
-        assert!(v.get("goal").is_none());
-        assert_eq!(
-            v.get("entry")
-                .and_then(|e| e.get("start_url"))
-                .and_then(|u| u.as_str()),
-            Some("https://x.com/editor")
-        );
-        let round: Trace = serde_json::from_value(v).unwrap();
-        assert_eq!(round, trace);
+        assert_eq!(schema["if"]["properties"]["version"]["type"], "integer");
+        assert_eq!(schema["then"]["$ref"], "#/definitions/TraceV3");
+        assert_eq!(schema["else"]["$ref"], "#/definitions/TraceV2");
     }
 
     #[test]
-    fn discriminated_union_click_ignores_extra_key_field() {
-        let bad = json!({
+    fn recorded_trace_schema_includes_v2_and_v3() {
+        let schema = serde_json::to_value(schemars::schema_for!(RecordStopResult)).unwrap();
+        assert_classifies_by_integer_version(&schema["definitions"]["RecordedTrace"]);
+        assert_eq!(
+            schema["definitions"]["TraceV3"]["properties"]["version"]["const"],
+            3
+        );
+    }
+
+    #[test]
+    fn recorded_trace_schema_follows_classify_value() {
+        let standalone = serde_json::to_value(schemars::schema_for!(RecordedTrace)).unwrap();
+        assert_classifies_by_integer_version(&standalone);
+        assert!(standalone["definitions"].get("TraceV2").is_some());
+        assert!(standalone["definitions"].get("TraceV3").is_some());
+
+        let stop_result = serde_json::to_value(schemars::schema_for!(RecordStopResult)).unwrap();
+        assert_classifies_by_integer_version(&stop_result["definitions"]["RecordedTrace"]);
+    }
+
+    #[test]
+    fn standalone_trace_schema_is_recorded_trace_union() {
+        let schema = serde_json::to_value(schemars::schema_for!(RecordedTrace)).unwrap();
+        assert_eq!(schema["title"], "RecordedTrace");
+        assert_classifies_by_integer_version(&schema);
+        assert!(schema["definitions"].get("TraceV2").is_some());
+        assert!(schema["definitions"].get("TraceV3").is_some());
+    }
+
+    #[test]
+    fn recorded_trace_accepts_v2_with_unknown_extension_fields() {
+        let v2 = json!({
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "entry": { "start_url": "https://example.com/" },
+            "pages": [{ "id": "p1", "url": "https://example.com/" }],
+            "steps": [],
+            "meta": { "tool": "legacy-exporter" }
+        });
+        match RecordedTrace::classify_value(&v2).unwrap() {
+            RecordedTrace::V2(trace) => assert_eq!(trace.pages.len(), 1),
+            other => panic!("expected v2, got {other:?}"),
+        }
+    }
+
+    fn v2_click() -> serde_json::Value {
+        json!({
             "op": "click",
             "id": 1,
             "page": "p1",
-            "target": { "tag": "button", "name": "OK" },
-            "key": "Enter"
-        });
-        let step: Step = serde_json::from_value(bad).unwrap();
-        assert!(matches!(step, Step::Click { .. }));
-        let v = serde_json::to_value(&step).unwrap();
-        assert!(v.get("key").is_none());
+            "target": { "tag": "button", "role": "button", "name": "发布" }
+        })
+    }
+
+    fn v3_click() -> serde_json::Value {
+        json!({
+            "op": "click",
+            "id": 1,
+            "state": "s1",
+            "result": { "state": "s2" },
+            "target": { "ref": "e1", "role": "button", "name": "发布" }
+        })
+    }
+
+    fn assert_step_classifies_by_state(schema: &serde_json::Value) {
+        assert_eq!(
+            schema["if"]["required"],
+            json!(["state"]),
+            "state is the RecordedStep classification key"
+        );
+        assert_eq!(schema["then"]["$ref"], "#/definitions/StepV3");
+        assert_eq!(schema["else"]["$ref"], "#/definitions/StepV2");
+        let mut forbidden = schema["not"]["required"]
+            .as_array()
+            .expect("RecordedStep schema must reject mixed page + state steps")
+            .iter()
+            .filter_map(|v| v.as_str())
+            .collect::<Vec<_>>();
+        forbidden.sort_unstable();
+        assert_eq!(forbidden, ["page", "state"]);
     }
 
     #[test]
-    fn extension_trace_deserializes() {
-        let v = json!({
-            "recorded_at": "2026-07-21T08:00:00Z",
-            "started_at": "2026-07-21T07:59:00Z",
-            "purpose": "demo",
-            "entry": { "start_url": "https://example.com/editor" },
-            "pages": [
-                { "id": "p1", "url": "https://example.com/editor" },
-                { "id": "p2", "url": "https://example.com/p/99" }
-            ],
-            "steps": [
-                {
-                    "op": "fill",
-                    "id": 1,
-                    "page": "p1",
-                    "target": { "tag": "input", "role": "textbox", "name": "标题" },
-                    "value": "hello"
-                },
-                {
-                    "op": "click",
-                    "id": 2,
-                    "page": "p1",
-                    "target": { "tag": "button", "role": "button", "name": "发布" },
-                    "effect": { "navigated_to": "p2" }
-                }
-            ]
-        });
-        let trace: Trace = serde_json::from_value(v).unwrap();
-        assert_eq!(trace.entry.start_url, "https://example.com/editor");
-        assert_eq!(trace.pages.len(), 2);
-        assert_eq!(trace.steps.len(), 2);
+    fn recorded_step_classifies_v2_and_v3() {
+        match RecordedStep::classify_value(&v2_click()).unwrap() {
+            RecordedStep::V2(StepV2::Click { .. }) => {}
+            other => panic!("expected v2 click, got {other:?}"),
+        }
+        match RecordedStep::classify_value(&v3_click()).unwrap() {
+            RecordedStep::V3(StepV3::Click { .. }) => {}
+            other => panic!("expected v3 click, got {other:?}"),
+        }
+    }
+
+    #[test]
+    fn recorded_step_rejects_mixed_page_and_state() {
+        let mut mixed = v2_click();
+        mixed["state"] = json!("s1");
+        mixed["result"] = json!({ "state": "s2" });
+        assert!(RecordedStep::classify_value(&mixed).is_err());
+    }
+
+    #[test]
+    fn recorded_step_schema_follows_classify_value() {
+        let schema = serde_json::to_value(schemars::schema_for!(RecordedStep)).unwrap();
+        assert_eq!(schema["title"], "RecordedStep");
+        assert_step_classifies_by_state(&schema);
+        assert!(schema["definitions"].get("StepV2").is_some());
+        assert!(schema["definitions"].get("StepV3").is_some());
     }
 }

crates/bsk-protocol/src/tools/record_common.rs

@@ -0,0 +1,7 @@
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct TraceEntry {
+    pub start_url: String,
+}

crates/bsk-protocol/src/tools/record_v2.rs

@@ -0,0 +1,330 @@
+//! Trace v2 — record-only user-action log with `pages[]` and step `page` refs.
+//!
+//! Legacy wire format with no top-level `version` field.
+
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
+use super::interaction::KeyModifier;
+use super::record_common::TraceEntry;
+
+/// Stable semantic handle for an interacted element (v2).
+///
+/// `name` and `nearby_label` are **untrusted page text**.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct TargetDescriptorV2 {
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub role: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub name: Option<String>,
+    pub tag: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub name_attr: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub placeholder: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub nearby_label: Option<String>,
+}
+
+/// Page context dictionary entry — referenced by steps via `page` id.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct PageRefV2 {
+    pub id: String,
+    pub url: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub title: Option<String>,
+}
+
+/// One selected option (`select` op).
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct SelectedOptionV2 {
+    pub value: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub label: Option<String>,
+}
+
+/// Observed navigation after a step (objective fact only).
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct StepEffectV2 {
+    /// Reference into `pages[]` for the destination page.
+    pub navigated_to: String,
+}
+
+/// Fields shared by every v2 step variant (flattened in JSON).
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct StepCommonV2 {
+    pub id: u32,
+    /// Reference into `pages[]`.
+    pub page: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub effect: Option<StepEffectV2>,
+}
+
+/// One recorded user action — discriminated union by `op` (v2).
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[serde(tag = "op", rename_all = "snake_case")]
+pub enum StepV2 {
+    Navigate {
+        #[serde(flatten)]
+        common: StepCommonV2,
+        to: String,
+    },
+    Click {
+        #[serde(flatten)]
+        common: StepCommonV2,
+        target: TargetDescriptorV2,
+    },
+    Hover {
+        #[serde(flatten)]
+        common: StepCommonV2,
+        target: TargetDescriptorV2,
+    },
+    Fill {
+        #[serde(flatten)]
+        common: StepCommonV2,
+        target: TargetDescriptorV2,
+        value: String,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        redacted: Option<bool>,
+    },
+    Select {
+        #[serde(flatten)]
+        common: StepCommonV2,
+        target: TargetDescriptorV2,
+        selection: Vec<SelectedOptionV2>,
+    },
+    Press {
+        #[serde(flatten)]
+        common: StepCommonV2,
+        key: String,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        modifiers: Option<Vec<KeyModifier>>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        target: Option<TargetDescriptorV2>,
+    },
+}
+
+/// Persisted user-action trace exported by legacy `tool.record_stop` / `await`.
+///
+/// Unknown extension fields are ignored so older traces remain readable.
+/// `states[]` and a numeric `version` are reserved for Trace v3 / `RecordedTrace`
+/// classification — serde still ignores them, but the JSON Schema rejects them.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct TraceV2 {
+    /// RFC 3339 timestamp when recording stopped.
+    pub recorded_at: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub started_at: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub purpose: Option<String>,
+    pub entry: TraceEntry,
+    pub pages: Vec<PageRefV2>,
+    pub steps: Vec<StepV2>,
+}
+
+fn constrain_trace_v2_schema(mut schema: schemars::schema::Schema) -> schemars::schema::Schema {
+    let schemars::schema::Schema::Object(obj) = &mut schema else {
+        return schema;
+    };
+    obj.metadata().title = Some("TraceV2".into());
+    obj.metadata().description = Some(
+        "Persisted user-action trace exported by legacy `tool.record_stop` / `await`.\n\n\
+         Unknown extension fields are ignored so older traces remain readable. \
+         `states[]` and a numeric `version` are reserved for Trace v3 / `RecordedTrace` classification."
+            .into(),
+    );
+
+    let object = obj.object.get_or_insert_with(Default::default);
+    object
+        .properties
+        .insert("states".into(), schemars::schema::Schema::Bool(false));
+    object.properties.insert(
+        "version".into(),
+        schemars::schema::SchemaObject {
+            metadata: Some(Box::new(schemars::schema::Metadata {
+                description: Some(
+                    "Numeric version selects Trace v3. Legacy v2 envelopes omit this field.".into(),
+                ),
+                ..Default::default()
+            })),
+            subschemas: Some(Box::new(schemars::schema::SubschemaValidation {
+                not: Some(Box::new(
+                    schemars::schema::SchemaObject {
+                        instance_type: Some(schemars::schema::InstanceType::Integer.into()),
+                        ..Default::default()
+                    }
+                    .into(),
+                )),
+                ..Default::default()
+            })),
+            ..Default::default()
+        }
+        .into(),
+    );
+    schema
+}
+
+impl JsonSchema for TraceV2 {
+    fn schema_name() -> String {
+        "TraceV2".into()
+    }
+
+    fn json_schema(generator: &mut schemars::SchemaGenerator) -> schemars::schema::Schema {
+        #[derive(JsonSchema)]
+        #[allow(dead_code)]
+        struct TraceV2Shape {
+            /// RFC 3339 timestamp when recording stopped.
+            recorded_at: String,
+            started_at: Option<String>,
+            purpose: Option<String>,
+            entry: TraceEntry,
+            pages: Vec<PageRefV2>,
+            steps: Vec<StepV2>,
+        }
+
+        constrain_trace_v2_schema(TraceV2Shape::json_schema(generator))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    fn sample_common(id: u32) -> StepCommonV2 {
+        StepCommonV2 {
+            id,
+            page: "p1".into(),
+            effect: None,
+        }
+    }
+
+    fn sample_target() -> TargetDescriptorV2 {
+        TargetDescriptorV2 {
+            role: Some("button".into()),
+            name: Some("发布".into()),
+            tag: "button".into(),
+            name_attr: None,
+            placeholder: None,
+            nearby_label: None,
+        }
+    }
+
+    #[test]
+    fn trace_v2_has_no_version_field() {
+        let trace = TraceV2 {
+            recorded_at: "2026-07-17T09:01:10Z".into(),
+            started_at: None,
+            purpose: None,
+            entry: TraceEntry {
+                start_url: "https://example.com/".into(),
+            },
+            pages: vec![PageRefV2 {
+                id: "p1".into(),
+                url: "https://example.com/".into(),
+                title: None,
+            }],
+            steps: vec![StepV2::Click {
+                common: sample_common(1),
+                target: sample_target(),
+            }],
+        };
+        let v = serde_json::to_value(&trace).unwrap();
+        assert!(v.get("version").is_none());
+        assert!(v.get("pages").is_some());
+        assert!(v.get("states").is_none());
+    }
+
+    #[test]
+    fn extension_v2_trace_deserializes() {
+        let v = json!({
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "started_at": "2026-07-21T07:59:00Z",
+            "purpose": "demo",
+            "entry": { "start_url": "https://example.com/editor" },
+            "pages": [
+                { "id": "p1", "url": "https://example.com/editor" },
+                { "id": "p2", "url": "https://example.com/p/99" }
+            ],
+            "steps": [
+                {
+                    "op": "fill",
+                    "id": 1,
+                    "page": "p1",
+                    "target": { "tag": "input", "role": "textbox", "name": "标题" },
+                    "value": "hello"
+                },
+                {
+                    "op": "click",
+                    "id": 2,
+                    "page": "p1",
+                    "target": { "tag": "button", "role": "button", "name": "发布" },
+                    "effect": { "navigated_to": "p2" }
+                }
+            ]
+        });
+        let trace: TraceV2 = serde_json::from_value(v).unwrap();
+        assert_eq!(trace.pages.len(), 2);
+        assert_eq!(trace.steps.len(), 2);
+    }
+
+    #[test]
+    fn v2_hover_steps_round_trip() {
+        let value = json!({
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "entry": { "start_url": "https://example.com/" },
+            "pages": [{ "id": "p1", "url": "https://example.com/" }],
+            "steps": [{
+                "op": "hover",
+                "id": 1,
+                "page": "p1",
+                "target": { "tag": "span", "role": "button", "name": "Account" }
+            }]
+        });
+
+        let trace: TraceV2 = serde_json::from_value(value).unwrap();
+        assert!(matches!(trace.steps.as_slice(), [StepV2::Hover { .. }]));
+        assert_eq!(
+            serde_json::to_value(&trace).unwrap()["steps"][0]["op"],
+            "hover"
+        );
+    }
+
+    #[test]
+    fn trace_v2_ignores_unknown_extension_fields() {
+        let value = json!({
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "entry": { "start_url": "https://example.com/" },
+            "pages": [{ "id": "p1", "url": "https://example.com/" }],
+            "steps": [],
+            "meta": { "tool": "legacy-exporter" }
+        });
+        let trace: TraceV2 = serde_json::from_value(value).unwrap();
+        assert_eq!(trace.pages.len(), 1);
+        assert!(trace.steps.is_empty());
+    }
+
+    #[test]
+    fn trace_v2_schema_allows_additional_properties() {
+        let schema = serde_json::to_value(schemars::schema_for!(TraceV2)).unwrap();
+        assert_ne!(
+            schema.get("additionalProperties"),
+            Some(&serde_json::Value::Bool(false)),
+            "Trace v2 must keep accepting traces with unknown extension fields"
+        );
+    }
+
+    #[test]
+    fn trace_v2_schema_forbids_classification_keys() {
+        let schema = serde_json::to_value(schemars::schema_for!(TraceV2)).unwrap();
+        assert_eq!(
+            schema["properties"]["states"],
+            json!(false),
+            "Trace v2 schema must reject states[] (reserved for v3)"
+        );
+        assert_eq!(
+            schema["properties"]["version"]["not"]["type"], "integer",
+            "Trace v2 schema must reject a numeric version (that selects the v3 path)"
+        );
+    }
+}

crates/bsk-protocol/src/tools/record_v3.rs

@@ -0,0 +1,428 @@
+//! Trace v3 — state-action-state log with `states[]` and step `state` refs.
+//!
+//! Wire format with top-level `version: 3`.
+
+use schemars::JsonSchema;
+use serde::{Deserialize, Deserializer, Serialize};
+
+use super::interaction::KeyModifier;
+use super::record_common::TraceEntry;
+
+pub const TRACE_VERSION_V3: u32 = 3;
+pub const VOM_FORMAT_VERSION: u32 = 1;
+
+fn deserialize_trace_v3_version<'de, D>(deserializer: D) -> Result<u32, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let version = u32::deserialize(deserializer)?;
+    if version != TRACE_VERSION_V3 {
+        return Err(serde::de::Error::custom(format!(
+            "unsupported trace version {version} (expected {TRACE_VERSION_V3})"
+        )));
+    }
+    Ok(version)
+}
+
+fn trace_v3_version_schema(_: &mut schemars::r#gen::SchemaGenerator) -> schemars::schema::Schema {
+    schemars::schema::SchemaObject {
+        instance_type: Some(schemars::schema::InstanceType::Integer.into()),
+        const_value: Some(serde_json::json!(TRACE_VERSION_V3)),
+        ..Default::default()
+    }
+    .into()
+}
+
+/// Stable semantic handle for an interacted element within a page observation.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct TargetDescriptorV3 {
+    #[serde(default, skip_serializing_if = "Option::is_none", rename = "ref")]
+    pub element_ref: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub role: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub name: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub ctx: Option<String>,
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub unmatched: bool,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct RecorderInfo {
+    pub bsk: String,
+    pub vom: u32,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub enum StopReason {
+    UserFinish,
+    CliStop,
+}
+
+/// Page observation dictionary entry — referenced by steps via `state` / `result.state`.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct TraceStateV3 {
+    pub id: String,
+    pub url: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub title: Option<String>,
+    /// Full page observation (front matter + VOM body + annotations).
+    pub body: String,
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub truncated: bool,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct StepResultV3 {
+    pub state: String,
+}
+
+/// Fields shared by every step variant (flattened in JSON).
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct StepCommonV3 {
+    pub id: u32,
+    /// Observation id immediately before this action.
+    pub state: String,
+    pub result: StepResultV3,
+}
+
+/// One selected option (`select` op).
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+pub struct SelectedOptionV3 {
+    pub value: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub label: Option<String>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub enum NavigationCause {
+    UserTyped,
+    Link,
+    FormSubmit,
+    Reload,
+    History,
+    Script,
+    Browser,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub enum FillCommit {
+    Enter,
+    Suggestion,
+    Blur,
+}
+
+/// One recorded user action — discriminated union by `op`.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[serde(tag = "op", rename_all = "snake_case")]
+pub enum StepV3 {
+    Navigate {
+        #[serde(flatten)]
+        common: StepCommonV3,
+        to: String,
+        cause: NavigationCause,
+    },
+    Click {
+        #[serde(flatten)]
+        common: StepCommonV3,
+        target: TargetDescriptorV3,
+    },
+    Hover {
+        #[serde(flatten)]
+        common: StepCommonV3,
+        target: TargetDescriptorV3,
+    },
+    Fill {
+        #[serde(flatten)]
+        common: StepCommonV3,
+        target: TargetDescriptorV3,
+        value: String,
+        commit: FillCommit,
+        #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+        redacted: bool,
+    },
+    Select {
+        #[serde(flatten)]
+        common: StepCommonV3,
+        target: TargetDescriptorV3,
+        #[serde(default, skip_serializing_if = "Vec::is_empty")]
+        selection: Vec<SelectedOptionV3>,
+    },
+    Press {
+        #[serde(flatten)]
+        common: StepCommonV3,
+        key: String,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        modifiers: Option<Vec<KeyModifier>>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        target: Option<TargetDescriptorV3>,
+    },
+    Scroll {
+        #[serde(flatten)]
+        common: StepCommonV3,
+    },
+}
+
+/// Wire trace returned by `tool.record_stop` / `await`.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
+#[serde(deny_unknown_fields)]
+pub struct TraceV3 {
+    #[serde(deserialize_with = "deserialize_trace_v3_version")]
+    #[schemars(schema_with = "trace_v3_version_schema")]
+    pub version: u32,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub purpose: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub started_at: Option<String>,
+    pub recorded_at: String,
+    pub stopped_by: StopReason,
+    pub entry: TraceEntry,
+    pub recorder: RecorderInfo,
+    pub states: Vec<TraceStateV3>,
+    pub steps: Vec<StepV3>,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    fn sample_common(id: u32, state: &str, result_state: &str) -> StepCommonV3 {
+        StepCommonV3 {
+            id,
+            state: state.into(),
+            result: StepResultV3 {
+                state: result_state.into(),
+            },
+        }
+    }
+
+    fn sample_target() -> TargetDescriptorV3 {
+        TargetDescriptorV3 {
+            element_ref: Some("e21".into()),
+            role: Some("button".into()),
+            name: Some("发布".into()),
+            ctx: Some("金桔柠檬 6 号".into()),
+            unmatched: false,
+        }
+    }
+
+    fn sample_trace() -> TraceV3 {
+        TraceV3 {
+            version: TRACE_VERSION_V3,
+            purpose: Some("把草稿商品发布上架".into()),
+            started_at: Some("2026-08-10T02:10:41.080Z".into()),
+            recorded_at: "2026-08-10T02:12:55.360Z".into(),
+            stopped_by: StopReason::UserFinish,
+            entry: TraceEntry {
+                start_url: "https://example.com/".into(),
+            },
+            recorder: RecorderInfo {
+                bsk: "0.1.10".into(),
+                vom: VOM_FORMAT_VERSION,
+            },
+            states: vec![
+                TraceStateV3 {
+                    id: "s1".into(),
+                    url: "https://example.com/".into(),
+                    title: Some("Example Domain".into()),
+                    body: "@vom 1\nRootWebArea \"Example Domain\"".into(),
+                    truncated: false,
+                },
+                TraceStateV3 {
+                    id: "s2".into(),
+                    url: "https://shop.example.com/products?status=draft".into(),
+                    title: Some("商品管理".into()),
+                    body: "@vom 1\nRootWebArea \"商品管理\"".into(),
+                    truncated: false,
+                },
+            ],
+            steps: vec![
+                StepV3::Navigate {
+                    common: sample_common(1, "s1", "s2"),
+                    to: "https://shop.example.com/products?status=draft".into(),
+                    cause: NavigationCause::UserTyped,
+                },
+                StepV3::Fill {
+                    common: sample_common(2, "s2", "s2"),
+                    target: TargetDescriptorV3 {
+                        element_ref: Some("e12".into()),
+                        role: Some("textbox".into()),
+                        name: Some("搜索商品".into()),
+                        ctx: None,
+                        unmatched: false,
+                    },
+                    value: "金桔柠檬".into(),
+                    commit: FillCommit::Enter,
+                    redacted: false,
+                },
+                StepV3::Click {
+                    common: sample_common(3, "s2", "s2"),
+                    target: sample_target(),
+                },
+            ],
+        }
+    }
+
+    #[test]
+    fn step_click_round_trips() {
+        let step = StepV3::Click {
+            common: sample_common(1, "s1", "s2"),
+            target: sample_target(),
+        };
+        let v = serde_json::to_value(&step).unwrap();
+        assert_eq!(v.get("op").and_then(|v| v.as_str()), Some("click"));
+        assert_eq!(v.get("state").and_then(|v| v.as_str()), Some("s1"));
+        assert_eq!(v["result"]["state"], "s2");
+        assert_eq!(v["target"]["ref"], "e21");
+        let round: StepV3 = serde_json::from_value(v).unwrap();
+        assert_eq!(round, step);
+    }
+
+    #[test]
+    fn step_fill_with_commit_round_trips() {
+        let step = StepV3::Fill {
+            common: sample_common(2, "s2", "s3"),
+            target: TargetDescriptorV3 {
+                element_ref: Some("e12".into()),
+                role: Some("textbox".into()),
+                name: Some("搜索商品".into()),
+                ctx: None,
+                unmatched: false,
+            },
+            value: "browser skill".into(),
+            commit: FillCommit::Enter,
+            redacted: false,
+        };
+        let v = serde_json::to_value(&step).unwrap();
+        assert_eq!(v["op"], "fill");
+        assert_eq!(v["commit"], "enter");
+        assert!(v.get("redacted").is_none());
+        let round: StepV3 = serde_json::from_value(v).unwrap();
+        assert_eq!(round, step);
+    }
+
+    #[test]
+    fn step_fill_password_is_redacted() {
+        let step = StepV3::Fill {
+            common: sample_common(1, "s1", "s1"),
+            target: TargetDescriptorV3 {
+                element_ref: Some("e3".into()),
+                role: Some("textbox".into()),
+                name: Some("密码".into()),
+                ctx: None,
+                unmatched: false,
+            },
+            value: "***".into(),
+            commit: FillCommit::Blur,
+            redacted: true,
+        };
+        let v = serde_json::to_value(&step).unwrap();
+        assert_eq!(v["value"], "***");
+        assert_eq!(v["redacted"], true);
+    }
+
+    #[test]
+    fn step_navigate_with_cause_round_trips() {
+        let step = StepV3::Navigate {
+            common: sample_common(1, "s1", "s2"),
+            to: "https://example.com".into(),
+            cause: NavigationCause::UserTyped,
+        };
+        let v = serde_json::to_value(&step).unwrap();
+        assert_eq!(v["op"], "navigate");
+        assert_eq!(v["cause"], "user_typed");
+        let round: StepV3 = serde_json::from_value(v).unwrap();
+        assert_eq!(round, step);
+    }
+
+    #[test]
+    fn trace_v3_round_trips() {
+        let trace = sample_trace();
+        let v = serde_json::to_value(&trace).unwrap();
+        assert_eq!(v.get("version").and_then(|v| v.as_u64()), Some(3));
+        assert!(v.get("pages").is_none());
+        assert_eq!(v["recorder"]["vom"], 1);
+        assert_eq!(v["states"].as_array().unwrap().len(), 2);
+        let round: TraceV3 = serde_json::from_value(v).unwrap();
+        assert_eq!(round, trace);
+    }
+
+    #[test]
+    fn default_fields_are_omitted() {
+        let step = StepV3::Click {
+            common: sample_common(1, "s1", "s1"),
+            target: TargetDescriptorV3 {
+                element_ref: Some("e1".into()),
+                role: Some("button".into()),
+                name: Some("OK".into()),
+                ctx: None,
+                unmatched: false,
+            },
+        };
+        let v = serde_json::to_value(&step).unwrap();
+        assert!(v.get("unmatched").is_none());
+        assert!(v["target"].get("ctx").is_none());
+        assert!(v["target"].get("unmatched").is_none());
+    }
+
+    #[test]
+    fn unmatched_target_serializes_flag() {
+        let step = StepV3::Click {
+            common: sample_common(1, "s1", "s2"),
+            target: TargetDescriptorV3 {
+                element_ref: None,
+                role: Some("button".into()),
+                name: Some("发布".into()),
+                ctx: None,
+                unmatched: true,
+            },
+        };
+        let v = serde_json::to_value(&step).unwrap();
+        assert_eq!(v["target"]["unmatched"], true);
+        assert!(v["target"].get("ref").is_none());
+    }
+
+    #[test]
+    fn extension_trace_deserializes() {
+        let v = json!({
+            "version": 3,
+            "recorded_at": "2026-07-21T08:00:00Z",
+            "started_at": "2026-07-21T07:59:00Z",
+            "purpose": "demo",
+            "stopped_by": "user_finish",
+            "entry": { "start_url": "https://example.com/editor" },
+            "recorder": { "bsk": "0.1.10", "vom": 1 },
+            "states": [
+                { "id": "s1", "url": "https://example.com/editor", "body": "@vom 1" },
+                { "id": "s2", "url": "https://example.com/p/99", "body": "@vom 1" }
+            ],
+            "steps": [
+                {
+                    "op": "fill",
+                    "id": 1,
+                    "state": "s1",
+                    "result": { "state": "s1" },
+                    "target": { "ref": "e1", "role": "textbox", "name": "标题" },
+                    "value": "hello",
+                    "commit": "blur"
+                },
+                {
+                    "op": "click",
+                    "id": 2,
+                    "state": "s1",
+                    "result": { "state": "s2" },
+                    "target": { "ref": "e2", "role": "button", "name": "发布" }
+                }
+            ]
+        });
+        let trace: TraceV3 = serde_json::from_value(v).unwrap();
+        assert_eq!(trace.version, 3);
+        assert_eq!(trace.states.len(), 2);
+        assert_eq!(trace.steps.len(), 2);
+    }
+}