Type-only change (brands are zero-cost casts; no runtime/wire impact). Closes the two gaps in the "brand ids that cross package boundaries" policy and fixes the dependency direction so a capability package never pulls in an unrelated one. - Extract the `Branded<B>` primitive into a new standalone type-only package `@deepseek-ai/dsh-brand` (packages/util/brand) with no harness-package deps. dsh-llm keeps its owned CallId but imports Branded from dsh-brand; dsh-session, dsh-agent, and dsh-bash all import Branded from there. dsh-bash depends on dsh-brand ALONE — never on dsh-llm or dsh-session (the architectural fix: a generic execution backend must not couple to the LLM or session vocabulary). - Mint BashTaskId + OwnerToken in dsh-bash and thread them through BashTask.id, the get/ownerOf/list/readOutput/kill seam, the bash-local generation site, and the dsh-tool-bash validate/access surface. OwnerToken is a DISTINCT brand from SessionId so the seam stays decoupled; dsh-tool-bash is the single boundary that casts SessionId -> OwnerToken. - Brand at the SOURCE, not via mid-pipeline casts: agent-loop's Config types agents[].id as AgentId and resumeSessionId as SessionId, so the brand enters at the config boundary and the inner create()/resume casts disappear (only the genuinely-new per-run session-id string is cast). - Stop brand erosion: propagate CallId/SessionId/AgentId to the registry/store Map keys and public params/exports (SessionStore, AgentRegistry + factory options, the ACP session-id surface + ToolPresenter CallId map, the persistence coordinator, invariants pendingCalls, the pi-ai tool-call maps). - Docs: document BashTaskId/OwnerToken in bash.md (type-equiv re-pasted), point the Branded type-equiv at dsh-brand, fix stale param types in the session/ agent/bash READMEs, regenerate the cordis catalog + module graph. Implements docs/rfc/proposed/architecture/2026-06-20-branded-ids.md
@deepseek-ai/dsh-session-persistence-jsonl
The JSONL durable session-persistence backend — a concrete SessionPersistence (the dsh-session-persistence seam). One append-only .jsonl event log per session.
On-disk layout
<root>/
cwd-<sha256(cwd)[:12]>/ # per-project bucket (or _no-cwd/ when no cwd)
<encoded-id>.jsonl # header line + one SessionEvent per line (verbatim)
- The first
.jsonlline is the immutableSessionHeadertagged{ type: 'session', version, id, cwd?, createdAt, parentSession? }; every subsequent line is oneSessionEventJSON, verbatim includingassistant/chunksoseqstays contiguous (events[i].seq === i). - Session ids are unvalidated branded strings, so they are percent-encoded to a single safe path segment before use (no traversal, no collision).
Config
| Key | Type | Notes |
|---|---|---|
root |
string (required) |
Root directory for all session files. No default — a process.cwd() default would scatter files as the process's cwd changes (bash calls, subprocesses). |
Durability and crash semantics
- Lazy materialization.
create(meta)writes nothing; the.jsonl(header + first batch) is written atomically (temp-write +fsync+ rename) on the firstappend. A created-but-never-appended session leaves nothing on disk and is absent fromlist. - Append-only. Committed events (at or below a flushed
turn/end) are never rewritten. Subsequent appends are line appends at EOF +fsync. - Crash recovery — close, don't truncate. A crash can leave a log whose final turn never closed (real events after the last
turn/end).loadPRESERVES those events (a turn can be huge — they are real work) and closes the orphaned turn by durably appending synthetic boundary events: an errortool/resultfor everytool-callthe crash left unanswered (the loop logs the assistant message before running the tools, so a mid-tool crash leaves dangling calls — andderiveMessages()would replay an assistant tool-call with no result, which providers reject), then astep/endif a step was open, thenturn/end {kind:'interrupted'}, returning a balanced log. Only a never-fully-written torn tail fragment (a final line with no newline / unparseable) isftruncated away before the closers are written. See session persistence. - Contiguous-seq.
loadrejects a mid-log parse error orseqgap (unloadable);appendrejects a batch whose firstseqdoes not continue the stored log, and rejects non-JSON-serializableevent.datanaming the offending event type. - Format version. Only v1 is supported;
loadrejects an unknown version. While the harness is unreleased a format change bumps the version and rejects non-current logs — there is no migration (no persisted user data to preserve).
Write path
The plugin generalizes the example session-jsonl.ts: it subscribes to session/created (capture the header; persist a fork's seed once), session/event (snapshot each event when buffering — the live session.events object is mutable), and session/flush/dispose (drain the write-behind buffer through append). A per-session write cursor means a resumed session never re-appends already-stored events. Existing live sessions are seeded on plugin apply (HMR does not replay session/created). All backend operations for one session are serialized, and disposal awaits quiescence (every init + final drain) before returning, so no write lands after teardown.