github.com/tutti-os/tutti/packages/agent/activity-replication is the official versioned JSON contract for uploading canonical agent activity snapshots to a cloud projection.

The root package defines the wire batch, mutation, typed entity key, scopes, five projection snapshots, validation, and acknowledgement/rejection semantics. Canonical activity vocabulary comes from store-sqlite/canonical; this module does not define a second set of turn or interaction lifecycle values.

The conformance subpackage exposes backend-neutral fixtures through two interfaces that match the direction of data flow:

ProjectionBuilder seeds canonical state and builds the official mutations; the Tutti SQLite adapter and tsh local builder run ProjectionFixtures.
Sink applies official mutations and reads the final projection; tsh-server MySQL runs SinkFixtures.

The sink fixtures verify that:

an already committed mutation retried after its HTTP response was lost is accepted as a duplicate and returns its original cursor;
a stale snapshot is an acknowledged no-op and does not block later ordered mutations;
reusing a mutation ID for a different identity is a permanent rejection;
schema rejection reports the failing mutation and transaction IDs.

The contract owns no database queries, room authorization, transport, WebSocket behavior, or GUI-derived state. runtimeOperation, runtimeOperationEvent, and submitClaim are retained only as entity names for decoding tombstone deletes; new upserts are invalid.

Turn.identityAnchorTurnId is an optional, provider-neutral identity relation. When present, the Turn inherits the ultimate external identity of another Turn in the same canonical Session; absence means the Turn owns its identity. The anchor is immutable, non-self-referential, and flattened to one hop by the canonical store. It does not change lifecycle, cancellation, interaction, provider-Turn binding, or message ownership. Cloud sinks must treat an omitted field as “not asserted” and must not clear an anchor already stored by a newer owner. This keeps old owners readable while limiting the new behavior to owners that actually emit the relation.

The production module depends only on the nested, dependency-free store-sqlite/canonical module. The SQLite conformance adapter lives in the store module's tests, so importing this contract does not add the SQLite driver or daemon to a consumer's module graph.

Consumers should validate an ordered batch with ValidateBatch, preserve the original durable cursor for duplicate acknowledgements, count duplicate and stale mutations in acceptedCount, and use SummarizeAcknowledgements to produce the batch result. ProjectionEpoch is an explicit rebaseline fence: when a cloud projection is destructively reset, its paired consumer release must increment the epoch. Clients then treat acknowledgement rows from an older epoch as untrusted and replay the canonical projection in dependency order before relying on cloud-derived features. The cloud sink must be deployed before clients that emit the new field; it rejects a different epoch rather than applying a partially compatible projection. This is an intentional fail-closed release fence, not a compatibility mode.