3b91135923
Review finding (Codex round 1): abstract erases at runtime and @deepseek-ai/dsh-tasks used to be the mountable registry, so a stale composition row would register a ctx.tasks with no method implementations and fail far from the misconfiguration. The seam constructor now rejects direct mounts with a load-time pointer at dsh-tasks-local; the seam suite pins the fence, the Agent Note cost paragraph records the actual behavior, and the stale tool-pty README requirement line names the implementation package.
@deepseek-ai/dsh-tasks
The background task registry seam (ctx.tasks). The abstract TaskService and its vocabulary types give long-running producers shared ids, owner isolation, reads, cancellation, waiting, notices, and cleanup under one contract; the process-local registry lives in dsh-tasks-local. Producer plugins extend TaskKindMap with their opaque id namespace.
Service contract
start(spec): TaskIdvalidates the control surface, spec, exact live owner, and optional positiveoutputLimitBytesbefore calling the producer'srun()once. A starter throw leaves nothing registered; successful return commits without another failable step.get(id, caller?)andlist(caller?)return non-consuming snapshots. Listing includes only caller-owned and unowned tasks.read(id, caller?)consumes the single cursor for stream tasks and reads terminal output idempotently for final-output tasks.kill(id, caller?, reason?)invokes producer cancellation before changing status. A cancellation throw leaves the task running; success changes it tostoppingand marks terminal delivery reported.wait(id, timeoutMs, caller?, signal?)returns a terminal snapshot or the live snapshot at timeout. Aborting stops only the wait; settlement wins once it has committed terminal delivery to that waiter.onTaskDone(listener)observes each terminal record with the exact owner. Listener throws and rejections are contained; listener work is not awaited.attachSurface(name)declares a control surface for its effect lifetime.start()fails before producer execution when none is attached.
Owned access compares the task's SessionId with the caller's. Ids such as bash-1 are predictable, so this fence is the boundary. Unowned tasks are open to callers and last until service disposal.
outputLimitBytes is producer-owned model-presentation policy carried unchanged into snapshots. A control surface applies it after adding status or notice metadata; the registry does not rewrite producer output or invent a default for producers that omit it.
Implementations also owe the lifecycle semantics of the contract: registrations outlive producer and control-surface fibers, owner and service disposal cancel live work and await compliant producers, and settlement is first-wins — one terminal record, one round of contained listener notification, released waiters.
See the task type catalog, the runtime Agent Note, and the seam Agent Note.
Model Experience
Indirectly, through producer plugins and dsh-tool-tasks, which render task ids, output, status, cancellation, and completion notices.
KV Cache effect
No direct invalidation; the named consumer owns any request-prefix changes.
Known Limitations and Deferred Work
- Stream output has one consuming cursor — independent observers need a cursor or snapshot API.
- Foreground work cannot be promoted — producers choose foreground or background before starting.
- The contract is in-process —
TaskStart.run()passes callbacks and exactAgentobjects; a durable or cross-process backend must reshape identity, restart, ownership, and observation semantics before it can implement this seam.