The daemon accepts only one unfinished command per session; the
thumbnail loop racing a model tool call produced 'session already has
an unfinished command' failures on both sides (found by the Phase 1-C
e2e: navigate/snapshot/click all errored while captures kept running).
Add a KeyedExecutor: every command for a session — tool calls and
observation captures alike — runs FIFO; queued tasks reject early on
abort, running tasks keep the runner's signal-driven kill.
Per-session live observation for owned sessions only, feeding the
upcoming client overlay:
- State model: SessionObservation (sessionId/url/action/since/
thumbnailAttachmentId/lastError), one entry per owned session;
added on start, removed on stop, cleared on dispose.
- Instrumentation: the shared runBsk wrapper begins/ends an action
(tool name mapped to a verb) around every model-facing call and tags
the child with its session id; action end triggers an immediate
thumbnail refresh.
- Thumbnail loop: 1.5s cadence while active, 8s idle downclock, x3
failure backoff, silent frame retention on errors; captures run
OUTSIDE the instrumentation (no action events, no current-pointer
movement) and land in the attachment store by reference.
- Interrupt: runner.killFor(tag) kills exactly the tagged in-flight bsk
children — chat-Stop-equivalent semantics for the current or a named
owned session; foreign ids and the no-in-flight case return false.
- Remote seam: dsh 0.1's Typert Remote pipeline and forwarded-event
allowlist are closed to out-of-tree packages, so state/events/
interrupt are served over the documented webServer route seam:
GET /bsk-observation/state, GET /bsk-observation/events (SSE),
POST /bsk-observation/interrupt; routes mount only when a webServer
service exists (headless compositions skip them).
- Config: observationEnabled (true), thumbnailIntervalMs (1500),
idleIntervalMs (8000).
Tests (+13, 72 total): state machine + event stream, cadence fast/idle/
backoff, headless no-store silence, observation-traffic isolation,
interrupt routing (default/specified/none/foreign), HTTP route
handlers, disabled-webServer no-op.
Tighten the shared-daemon boundary from 'cleanup only touches owned
sessions' to 'the plugin only ever sees and operates on sessions it
created':
- browser_session_list no longer queries the daemon at all; it returns
the plugin's own session table (with the current marker), so foreign
sessions cannot even be enumerated through the plugin.
- Every tool's optional session argument must name a plugin-created
session; foreign/unknown ids are rejected with a clear error before
any command reaches the daemon (the reference-adoption channel is
gone).
- Unchanged: dispose stops exactly the owned set, stop requires
ownership, the start reservation protocol, and handle-precise child
kills.
Tests updated (59): explicit-foreign rejection without daemon contact,
registry-only listing, reservation race, stale-handle-tolerant dispose.
e2e: a manually started foreign session was rejected on reference,
absent from session_list, refused on stop, and survived dispose while
both plugin sessions were cleaned up.
Review hardening for daemon-sharing deployments (other agents,
terminals, or dsh instances on the same bsk daemon):
- Ownership split: only sessions created by browser_session_start are
'owned'. Explicitly referenced foreign sessions are still tracked for
the current-session pointer, but browser_session_stop refuses them
and unload cleanup stops exactly the owned set — no path can stop a
session this plugin did not create.
- Start race: the capacity check is now a synchronous
reserveStart/completeStart/abandonStart protocol, so two concurrent
starts can never both pass the cap (check-and-reserve is atomic on
the event loop); a rejected or failed start never leaks a session.
- Stale handles: dispose already swallowed per-stop errors; the owned
set is computed at dispose time so an externally stopped session is a
no-op, not a failure.
Tests (+7): reservation race (two concurrent starts, cap 1 -> exactly
one spawn), foreign-stop refusal (no stop command reaches the daemon),
reference adoption never becoming owned, resolveForStop pointer
stability, and an apply-level dispose test proving only owned sessions
are stopped while stale stops are tolerated. e2e: a manually started
foreign session survived the plugin's full lifecycle while both plugin
sessions were cleaned up.
browser_screenshot on an image-capable route returns text + image
blocks; the shared result presenter required exactly one text block and
bailed to the generic card (tool name + raw args). Project the first
text block instead so the terminal card shows in both modes.
The concurrency cap was checked in registry.add() AFTER
`bsk session start` had already created the session, so a rejected
start leaked a live session outside the plugin's tracking (found by the
real-browser e2e: the rejected third session stayed in
`bsk session list` after dispose). Check capacity before spawning;
registry.add() keeps the same check as a backstop.
Add a new monorepo package that registers BrowserSkill (bsk) browser
automation as model-visible tools in DeepSeek Harness (dsh):
- 11 tools mapping to bsk CLI --json commands: session start/stop/list,
navigate, snapshot, observe, click, fill, press, screenshot, emulate
- multi-session support: optional session arg with a current-session
pointer, session id echoed in every result, configurable concurrency
cap (default 5), and dispose-time cleanup of plugin-started sessions
- cancellation: exec.signal aborts kill the underlying bsk child process
- terminal-style UI cards (command line as the call card, output as the
result card); screenshots inline the PNG through the host attachment
store when the model route accepts image input, else return the path
- config: bskPath / defaultTimeoutMs / maxSessions via Schemastery schema
- install guidance when the bsk binary is missing; bsk JSON error
envelopes (code/message/hint) surfaced to the model
- unit tests mock the bsk runner (no real browser required); the root
lint script now also runs the package's typecheck + tests so the
existing CI frontend job covers the new package (a dedicated CI job
diff is provided in the PR; the pushing token lacks workflow scope)
BB-fat