Add the durable session-persistence capability seam (ADR 0016): an
abstract SessionPersistence service (dsh-session-persistence,
ctx.sessionPersistence) defining create/append/load/list/has/delete/
update over the existing SessionEvent — no parallel persisted type — and
a first implementation (dsh-session-persistence-jsonl): an append-only
JSONL log per session with crash-safe atomic writes, truncation-repair
of a never-committed crash tail, and a read/replay path. SessionMeta
(format version, cwd, lineage) travels out-of-log via session.header.
A shared runPersistenceContract suite holds every backend to the same
append-only / contiguous-seq / lazy-materialization / serializability
semantics.
Config-driven create() now uses a per-run ${id}-session-<uuid> session
id so a fixed name no longer collides with an on-disk log once a durable
backend is loaded; each run is a new session (a demo simplification). The
examples drop their hand-rolled session-jsonl.ts and load the JSONL
backend via cordis.yml; CI smoke-loads it too.
The agent-facing create/resume factory that consumes load() is a
separate seam, deferred to a follow-up; this change stops at the load
primitive and does not reach into the loop.
- 009: the crash-tail "overwrite" contradicted the append-only contract.
Name it explicitly as a one-time truncation-repair (ftruncate+fsync to
the last complete turn/end byte offset) that removes only the
never-committed crash tail; committed events are never rewritten.
Qualify the append/impl/ADR wording to match.
- 010: remove the remaining concrete-loop references — the session/new
and session/load table rows now point at the dsh-agent create/resume
factory, and the Risks disposal line uses the interface-level settle
signal (agent/status) instead of LoopAgent-only agent.done.
Resolve the inline review feedback on PR #18 (all verified against the
codebase, the published @agentclientprotocol/sdk@0.25.1 tarball, and
Cordis fiber semantics):
- 009: dsh-session owns SessionMeta (persistence re-exports) to avoid a
package cycle; split mutable summary into a sidecar so the event log
stays append-only and list/load can return it; pick one load-repair
rule (resume from the last complete turn/end, overwrite the orphan).
- 010: SDK has a zod peer dep + runtime zod/v4 import (drop "zero runtime
deps"); session/new needs a create seam taking {sessionId, meta};
propose an abstract create/resume factory on dsh-agent so the bridge
depends on the interface not the loop, and observe agent/status for
quiescence since agent.done is LoopAgent-only; add the explicit
TurnEndReason -> ACP StopReason wire mapping + test; reject non-empty
additionalDirectories for the MVP; remove the EOF blank line.
- 011: ctx.extend() does not create a disposable fiber — use a real
per-session disposer scope.
Three proposal documents, numbered in dependency order:
- RFC 009: an abstract, append-only, event-based SessionPersistence
service over the existing SessionEvent log (no parallel persisted
type), a JSONL impl, a SessionMeta header seam, and an async
AgentLoop.resume path. Design informed by Codex/Claude Code/
opencode/pi. Core design point; unblocks resume + ACP session/load.
- RFC 010: ACP (Agent Client Protocol) support as a dsh-acp
client-driver plugin on @agentclientprotocol/sdk, mapping ACP onto
the agent/* events and the tools/execute permission seam. Builds on
009 for session/load; single active session.
- RFC 011: multiplex concurrent ACP sessions over one connection
(bridge-layer change; downstream of 010).
Tianyi Cui