Committed feed streams

GET /events/stream replays the existing event log. GET /changes/stream replays complete transaction pages from the fact change feed, including named graph writes. Both are read-only SSE endpoints. Changes use transaction IDs; events use event offsets. Never submit a transaction ID to /events/commit.

Pass a nonnegative since, or Last-Event-ID. If both are supplied they must agree. Each quipu.events or quipu.changes frame contains the corresponding ordinary feed response as JSON; its SSE ID is the delivered page cursor. Delivery does not acknowledge a consumer. Persist the applied data and cursor atomically, and reconnect from that durable cursor after any failure.

SQLite commit hooks supply wake hints only. The stream crosses the writer barrier and reads the committed feed before delivery; a rolled-back savepoint or failed commit does not authorize an event. A watch channel coalesces hints; read-after-subscribe prevents a missed commit during subscription. An hourly backstop also checks for external writers. Fifteen-second heartbeat comments perform no database reads.

There are at most 64 active streams and one transaction/event per read page. Frames larger than 1 MiB terminate with an error event without acknowledging a cursor. This is an output budget, not a bound on the memory needed to read one large transaction. Consumers must refuse incomplete frames and retain the last applied cursor on errors, with bounded reconnect backoff. Event filters use types and group; transaction filters use graph. Combining unrelated filter kinds is refused.

Streaming is a source capability. Enabling a consumer, replaying production history, changing subscriptions or claiming scheduled acceptance requires its separate operational decision and measurements.