74502fa8c2
Carved out of #170 per review feedback — the foundation the workflow tool builds on, now standing alone on master: - dsh-tools: the structured-output JSON Schema subset (StructuredOutputSchema, assertSupportedOutputSchema, validateStructuredValue) — rejects loud outside the enforced subset, listing every violation - dsh-subagent: SubagentStartRequest.outputSchema / SubagentResult.structured become a real capability; the service rejects a schema'd request whose provider lacks it - dsh-subagent-inprocess: the shared structured runtime — one global structured_output capture tool, a prepend final-assembly listener that strips the placeholder for plain agents and swaps in the run's own schema (plus the calling instruction as a trailing section) for structured children, an agent/turn-continuation veto once captured, and the capture/nudge loop in the run driver (structuredNudgeRetries, cancellation honored mid-nudge); lifetime refcounted by backends and live runs - subagent-spawn / subagent-fork flip outputSchema: true One deliberate divergence from the #170 revision: the backends do NOT add 'tools' to their plugin inject. Doing so deferred their apply past the todo plugin, and the delegation tool mirrors provider lifecycle — so the model-visible tool order of every existing prompt changed, invalidating every recorded snapshot fixture. The runtime now gates its capture-tool registration on tools availability itself (sync when live, a scoped inject fiber when the Loader starts the backend first), keeping this PR byte-invisible to existing transcripts: all 35 snapshot scenarios pass against master's fixtures unchanged.
core/ — product API spine
The packages every harness build is assembled from: the session log, the system-prompt assembly, the tool registry, the agent vocabulary, and the one concrete loop that drives them. These are product packages — the stable surface plugins and consumers build against.
| Package | Role | ctx key |
|---|---|---|
session/ |
Event-sourced session log + in-memory store | ctx.sessions |
system-prompt/ |
Prompt-section + tool-schema assembly registry | ctx.systemPrompt |
tools/ |
Tool registry + tools/pre-execute/tools/post-execute pipeline |
ctx.tools |
agent/ |
Agent interface, registry, agent/* event vocabulary |
ctx.agents |
agent-loop/ |
The concrete loop plugin: ReactLoopAgent + the loop driver |
ctx.agentLoop |
agent-core/ |
Bundle plugin: the providerless/executor-less/UI-less spine as code | (loads the spine) |
agent-loop is the one concrete implementation of the agent seam and lives here because it is the harness's default product loop; everything else in core/ is interface/vocabulary. Plugins depend on the agent vocabulary, never on agent-loop directly, so the loop stays swappable.
agent-core is the composition counterpart: one bundle plugin that loads the whole providerless spine (timer + llm + sessions + system-prompt + tools + agents + invariants + tool-bash + agent-loop) and forwards agent-loop's agents list as its own config. App packages (ui/stdio-agent, ui/acp-agent) consume it and add only a front door; a leaf adds the swappable backends plus any optional product tools it wants to expose. It lives in core/ because it composes exclusively core/ + interface packages and ships no provider, executor, or UI of its own.