The seam vocabulary (SubagentStartRequest.outputSchema, SubagentResult
.structured) existed but no in-process backend honored it — spawn/fork
advertised outputSchema: false. This lands the missing half:
- dsh-tools gains a structured-output JSON Schema subset (json-schema.ts):
StructuredOutputSchema, assertSupportedOutputSchema (rejects loud outside
the enforced subset, every violation listed), validateStructuredValue
(path-qualified issues, total). outputSchema's seam type becomes this raw
JSON-Schema subset instead of the author-facing SchemaSpec DSL — the schema
travels verbatim to the model as a forced tool's parameters.
- dsh-subagent-inprocess gains the shared structured runtime: one global
structured_output capture tool (placeholder parameters) + a prepend:true
agent/request listener doing FINAL-REQUEST enforcement (strip for plain
agents, per-run schema for structured children — survives downstream
request-replacing listeners) + an agent/turn-continuation veto that stops
a child's turn once captured (no wasted extra model step). Lifetime is
refcounted by backends (plugin lifetime) AND live runs (start→settle).
- startInProcessRun drives the capture: subset asserted before the child
exists, instruction appended to the child's system prompt, clean-finish
nudge loop (structuredNudgeRetries, backend Config, default 1), captured
value on result.structured; a clean finish without a capture settles
'error' (never a silent success with a missing field).
- spawn + fork flip outputSchema: true and inject 'tools'.
Tianyi Cui
dafb81be7b