workflow: meta rides the seam as data — the engine never evaluates it

P1 review finding: extractMeta timed only the literal's vm evaluation;
materializing the RESULT then read properties ordinarily on the HOST
stack, so a meta literal smuggling a getter (get name() { while(true){} })
could wedge the host outside any timeout — defeating the exact spin
isolation the worker thread exists for.

Rather than harden the evaluator (descriptor walks, AST validation),
delete the mechanism: the workflow's identity now reaches the seam as a
plain JSON field (WorkflowStartRequest.meta), carried by the tool as a
schema-validated `meta` object parameter the model fills directly. The
engine only shape-validates data (validateMeta, every violation named)
and pre-parses the body; the scanner, the vm evaluation, and the
host-side materialization are gone, and with them the hole. A body
still opening with a Claude Code-style `export const meta` statement
gets a pointed SCRIPT_PARSE message (the likeliest authoring slip; a
CC script's body stays drop-in, only its meta header moves into the
parameter). syncTimeoutMs now governs exactly one thing: the initial
synchronous slice inside the worker.

The RFC's decision section is rewritten in place (implemented-RFC
rule); the embedded-meta format moves to alternatives-considered with
the hole as the reason. Tool description, presentation (title now reads
meta.name directly — the textual sniff is gone), seam vocabulary docs,
and catalogs follow.
This commit is contained in:
imccyu
2026-07-09 20:09:10 +08:00
parent af9616f47d
commit 0d0f0204f2
18 changed files with 304 additions and 462 deletions

View File

@@ -8,20 +8,21 @@ Source: [`packages/workflow/workflow/src/types.ts`](../../packages/workflow/work
## The start request
What a caller asks for when starting a run. The tool layer builds this from the model's `{ script, args }` plus the calling agent; the engine validates the script's meta block BEFORE the body runs. `parent` is REQUIRED — every child the script spawns is attributed to it (cwd, lineage, and depth flow through the [subagent seam](subagent.md)). `args` must be plain host-realm JSON data; the engine exposes it to the script as the `args` global.
What a caller asks for when starting a run. The tool layer builds this from the model's `{ script, meta, args }` call plus the calling agent; `meta` and `args` are plain JSON DATA (the engine shape-validates `meta` and rejects loud BEFORE anything runs — no script text is ever evaluated to obtain it). `parent` is REQUIRED — every child the script spawns is attributed to it (cwd, lineage, and depth flow through the [subagent seam](subagent.md)).
```ts type-equiv
interface WorkflowStartRequest {
script: string
meta: WorkflowMeta
args?: unknown
parent: Agent
signal?: AbortSignal
}
```
## The script's identity: `WorkflowMeta`
## The workflow's identity: `WorkflowMeta`
The validated `export const meta` block (Claude Code dynamic-workflows format — a PURE object literal heading the script). `phases` is progress vocabulary only: `phase()` calls match titles for observers; no execution structure is implied.
The identity block carried as data on the start request (the tool's `meta` parameter; the field vocabulary matches the Claude Code dynamic-workflows meta block). `phases` is progress vocabulary only: `phase()` calls match titles for observers; no execution structure is implied.
```ts type-equiv
interface WorkflowMeta {