Third application of the reference mechanism: session turns whose
system prompt + tools are byte-identical to the context predecessor's
materialized snapshot persist { agentId, model, inheritedFrom } instead
of ~70KB per turn (measured: turn 2 of a session is now ~1.1KB total).
Inheritance is decided at createTurn by equality against the
materialized predecessor; the model stays concrete, and on
materialization the inherited record's own agentId/model win — a rule
the new test matrix caught as a real bug (the chain base's model was
overriding a mid-session model switch). Reducer invariants: inherited
snapshots must reference the context predecessor; tool identity arrives
via invocation events.
Test matrix per review: prompt-diff -> full snapshot, tools-diff ->
full snapshot, model-switch -> inherits with concrete model, multi-hop
chains materialize, standalone turns never inherit, unreadable
predecessor falls back to full, cyclic inheritance is corruption,
sessions denormalize the model from inherited snapshots.
The inspector now handles sessions too (auto-detected): overview with
per-turn status/size/input preview, --turns to cascade full turn
inspection. Documented in a new repo-root AGENTS.md (storage layout,
reference model, inspector usage, invariants) with a CLAUDE.md pointer.
Breaking for dev turn files: wipe ~/.rowboat/storage.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Durable contracts for the new turn/session runtime, shared by core and
renderer:
- turns.ts: zod schemas for all 16 durable turn events, TurnContext
(previousTurnId ref | inline messages), ModelRequest with contextRef
and current-turn-only messages, ephemeral delta types, reduceTurn
enforcing every spec invariant, and pure derivations
(deriveTurnStatus, turnTranscript, outstanding work).
- sessions.ts: session_created/turn_appended/title_changed schemas,
reduceSession, and the SessionIndexEntry projection.
- vitest wiring for packages/shared (config, build-excluded tests);
92 tests covering happy paths, recovery-shaped histories, and one
named test per corruption invariant.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
