Tianyi Cui
1d43ea3cd5
A new capability family at packages/workflow/ in the bash seam shape,
modeled on Claude Code's dynamic workflows: the model writes a JavaScript
orchestration script (export const meta = {...} + plain-JS body), a runtime
executes it, and the script — not the conversation — holds the loop, the
branching, and the intermediate results.
- dsh-workflow (ctx.workflows): abstract WorkflowService + run vocabulary
(WorkflowRun whose result NEVER rejects) + observe-only workflow/* events
carrying data snapshots (id + meta, never the live run), per-listener
contained like subagent/*.
- dsh-workflow-vm: in-process node:vm engine. Meta extraction via a
string/comment-aware scanner (template interpolation rejected; literal
evaluated alone in an empty timed context; statement blanked line-
preservingly so stacks keep script line numbers). Hooks: agent(prompt,
{label, phase, schema, model}) over ctx.subagents, parallel(), pipeline()
(no cross-stage barrier), phase(), log(), args. Fatal-vs-null discipline:
hook misuse (unknown/deferred options, bad arguments, unsupported
schemas, tripped caps, seam start failures, cancellation) throws fatal
WorkflowErrors the combinators RE-THROW — never dissolved into the
per-item null reserved for child failures. Realm boundary: inbound values
materialized by descriptor walks that never invoke accessors (defineProperty
copies, __proto__-safe); outbound values rebuilt in-realm via the
context's own JSON.parse. Determinism bans (Date.now/Math.random/argless
new Date) kept so future resume support cannot break scripts. Caps and
timeouts are validated Config. Every hook promise carries a no-op
rejection consumer (app-boot exits on unhandled rejections).
- dsh-tool-workflow: the model-facing workflow tool, synchronous like
dsh-tool-subagent (start → await → try/finally dispose; abort bridged;
non-completed → isError). Generic render card titled by a textual
meta.name sniff. The tool description carries the authoring contract.
Wired into examples/{coding-agent,acp-agent} with explicit-ask-only
guidance. Coverage at every tier: unit (meta scanner, materializer incl.
counting-getter and __proto__ regressions, combinator semantics,
concurrency ceiling, caps, cancellation, no-unhandled-rejection abandon),
integration over the real spawn stack, with-key e2e (real two-phase run +
the tool through the registry pipeline), and a recorded ACP snapshot
scenario (workflow-run, 1 child session). RFC:
docs/rfc/implemented/feature/2026-07-05-dynamic-workflows.md (deferred
work explicitly listed). AGENTS.md budget 1575 → 1590 for the new group's
layout line.
@deepseek-ai/dsh-tool-workflow
The model-facing workflow tool: run a JavaScript orchestration script that fans out subagents, and return the script's final value. Pure schema + lifecycle shaping over ctx.workflows — script parsing, execution, caps, and cancellation live behind the seam, so a hardened engine swaps in without touching what the model sees.
What the model sees
Two parameters: script (required — the full export const meta = {...} + body text; the tool DESCRIPTION carries the complete authoring contract: hooks, semantics, determinism bans, the supported schema subset) and args (optional JSON object exposed to the script as the args global; a bare list is wrapped as a field, a deliberate deviation from Claude Code's any-JSON args so the wire schema stays honest).
Lifecycle
Collection is SYNCHRONOUS this cut (like dsh-tool-subagent): execute starts a run and awaits run.result inside a try/finally that always disposes the run, so the script and its children reach quiescence on every path. exec.signal is bridged to run.cancel() (including the already-aborted-before-start case). A non-completed stop reason maps to an isError result reporting the reason — never partial output as success; a parse/meta failure thrown synchronously by start() becomes an isError the model can correct from. The completed result renders the meta name, the agent count, and the return value as JSON, truncated at maxResultChars with an explicit notice.
Render intent
Decided up front (per the render-intent RFC): a generic card titled workflow: <meta.name>, the name sniffed TEXTUALLY from args.script (presentation must be a pure function of args, so it cannot ask the engine to parse); the script text rides as rawInput. The result keeps the generic card.
Config
| Key | Default | Meaning |
|---|---|---|
toolName |
workflow |
The model-facing tool name to register. |
maxResultChars |
50000 |
Rendered-result ceiling; longer JSON is truncated with a notice. |