Turtle
c58097a826
Write handles now hold a durable lease (session.lock.json beside the log): a random owner token, diagnostic pid, and an expiry. Acquisition wins by exclusive create; a second process's create or write open rejects while the record is unrenewed for less than leaseTtlMs (default 5 min), and takes over after that — a crashed holder is waited out, never reclaimed by pid. The holder renews every leaseRenewIntervalMs (default 4 min); a renewal that finds a foreign, vanished, or expired record — or fails outright — marks the lease lost permanently, so every later append/flush rejects with SessionOwnershipLostError while reads continue. Close releases the record; read handles never touch it. Takeover of an expired record is eventually exclusive: a replaced holder stops within one renewal interval. Refs #3245
description, kind
| description | kind |
|---|---|
| Package map for the durable session data plane: the persistence seam and its backends, checkpoint policy, projections, log-backed titles, and outbound session telemetry. | package-group |
session/ — durable session data plane
English | 中文
Summary
The session group makes an agent's conversation durable and reusable outside the live loop: the static format chain restores released generations, the persistence seam stores the event log and restores it on resume, the checkpoint policy keeps requests, tool side effects, and completed steps durable before the next action, projections serve whole log-derived values to client carriers, titles name each session from its content, and telemetry reports session activity outbound. Mount the shipped JSONL persistence provider first, then add the checkpoint policy and any projection, title, or telemetry packages the deployment needs. This page maps the group; every package README owns its contract, and session-query/ is a sibling group whose read/tool surface consumes persistence independently.
Table of Contents
Packages
The group splits into four families: durable storage (persistence seam, backends, checkpoint policy), projections, titles, and telemetry. Each package README owns its contract and configuration.
Persistence
| Package | Role | ctx key |
|---|---|---|
session-format/ |
Pure adjacent-format chain and artifact validation library | library — no ctx key |
session-format-v0-to-v1/ |
Frozen released-v0 decoder and identity migration into released v1 | library — no ctx key |
session-format-v1-to-v2/ |
Frozen released-v1 decoder and cardinality-changing Assistant-stream migration into released v2 | library — no ctx key |
session-format-catalog/ |
Generated static catalog of shipped adjacent migrations | library — no ctx key |
session-persistence/ |
Defines the durable session-storage service and the shared write coordination every backend composes | ctx.sessionPersistence |
session-persistence-jsonl/ |
Shipped backend: immutable canonical generation filenames per Session with exclusive successor publication, optionally Zstandard-compressed | registers on ctx.sessionPersistence |
session-checkpoint-policy/ |
Makes model requests, top-level tool side effects, and completed steps durable before the next action | wraps ctx.llm and ctx.tools |
session-log-deepseek/ |
Uploads the incremental canonical log as optional official DeepSeek request metadata | contributes dsh_session_log |
Projection
| Package | Role | ctx key |
|---|---|---|
session-projection/ |
Defines and drives projection units that fold committed events into whole current values | ctx.sessionProjections |
session-projection-cache/ |
Persists projection checkpoints so cold reads skip full log loads | ctx.sessionProjectionCache |
session-stats/ |
Serves whole-log conversation counts and wall times through the sessionStats unit |
registers on ctx.sessionProjections |
session-turn-outline/ |
Serves the whole-log turn outline (turn, turn/start seq, prompt preview) through the turnOutline unit |
registers on ctx.sessionProjections |
Titles
| Package | Role | ctx key |
|---|---|---|
session-title/ |
Log-backed session titles with a deterministic fallback and one optional provider | ctx.sessionTitle |
session-title-llm/ |
Shared model-backed title-generation policy for the provider packages | library — no ctx key |
session-title-first-prompt-llm/ |
Titles a session from its first eligible human message | registers on ctx.sessionTitle |
session-title-all-prompts-llm/ |
Titles a session from all eligible human messages | registers on ctx.sessionTitle |
Telemetry
| Package | Role | ctx key |
|---|---|---|
session-telemetry/ |
Captures session activity and hands records to a configured reporting backend | ctx.sessionTelemetry |
session-telemetry-otel/ |
Delivers telemetry through OpenTelemetry logs in FULL, FEEDBACK_ONLY, or DISABLED mode |
registers on ctx.sessionTelemetry |
Only one title provider may register at a time; without one, the title service keeps its deterministic fallback. The subsystem pages below are the backend-neutral references for each family.
Related documentation
- Session persistence subsystem — backend-neutral service semantics, the flush checkpoint, and crash recovery.
- Session projections subsystem — the projection unit contract and drive semantics.
- Session titles subsystem — title eligibility, fallback, and provider flow.
- Session telemetry subsystem — capture, redaction, and delivery modes.
- Session subsystem — the live event log every package in this group persists or derives from.
Dev Note
None.