imccyu
4a15c8a479
emitWorkflowEvent's catch rendered the thrown value with a bare String(error), which itself throws when the value's toString / Symbol.toPrimitive throws — breaking the documented containment guarantee: such a listener could fail the run mid-emit, starve later listeners, and turn the detached workflow/end settle hook into an unhandled rejection. Render through a local total fallback instead (String in a try, a fixed label when even coercion throws); local because the seam sits below every engine and cannot import an engine's renderer. Regression: a listener throwing a coercion-trap value — the emit does not propagate and later listeners still run.
@deepseek-ai/dsh-workflow
The workflow seam (ctx.workflows): an abstract service defining WHAT a workflow engine does — execute a model-written orchestration script that fans out subagents — without saying HOW. The bash-shaped third of the workflow family: implementations subclass WorkflowService and register as the workflows service (one per context); dsh-workflow-vm is the first, and dsh-tool-workflow is the model-facing consumer.
Service: WorkflowService (abstract)
start(request: WorkflowStartRequest): WorkflowRun — parse and execute a script. Throws synchronously (SCRIPT_PARSE/META_INVALID) for a script that cannot begin; once a run is returned, its result NEVER rejects — every failure resolves with stopReason: 'error' (or 'cancelled') — and once the run is cancelled, result settles within the implementation's bounded grace even if the script itself never settles (a consumer awaiting result must never be wedged past a cancellation). dispose() must reach quiescence within a bounded grace (cancel → wait for the script to settle and its children to finish disposing → abandon), never hanging its caller.
The protected emitWorkflowEvent helper dispatches the workflow/* events with PER-LISTENER containment and PER-LISTENER payload snapshots (a throwing subscriber is logged, never propagated, and cannot starve later listeners; each subscriber gets its own clone of the payload, so mutating it corrupts neither the engine nor other listeners) — the same containment guarantee as the subagent seam's lifecycle emits.
Vocabulary
WorkflowStartRequest—{ script, args?, parent: Agent, signal? }.parentis REQUIRED: every child the script spawns is attributed to it.argsmust be plain host-realm JSON data.WorkflowMeta/WorkflowPhase— the script's validatedexport const metablock (Claude Code format: requiredname/description, optionalwhenToUse/phases).WorkflowRun—{ id, meta, result, cancel(reason?), dispose() }; the consumer awaitsresultand MUSTdisposeon every path.WorkflowResult—{ value, stopReason: 'completed'|'cancelled'|'error', error?, agentsStarted };valueis the script's materialized return (plain JSON data;nullfor no return).WorkflowError—HarnessErrorwith aWorkflowErrorCodeand afatalflag driving the combinator discipline: a fatal error (bad hook arguments, unsupported options/schemas, tripped caps, seam start failures, cancellation) always propagates throughparallel()/pipeline()instead of dissolving into a per-itemnull.isFatalWorkflowError(error)is the catch-site predicate.
Events
All observe-only emits carrying DATA SNAPSHOTS (WorkflowRunInfo = id + meta) — never the live WorkflowRun, so a listener cannot gain cancel/dispose; control stays with the start() caller:
workflow/start(info) /workflow/end(info, resultInfo) — run lifecycle;resultInfodeliberately omits the value.workflow/phase(info, title) /workflow/log(info, message) — script narration.workflow/agent-start(info, agent) /workflow/agent-end(info, agent + outcome) — one pair peragent()call, correlated byseq.
Non-goals (this cut)
Background collection, journaling/resume, saved workflows, nested workflow(), token budgets — see the RFC's deferred section.