0e0f3b2f19
The Codex simplification concern plus the duplication comment on the spawn apply, resolved by deletion: the backend-lifetime holds are gone, so the runtime registers at the first structured run and disposes when the last settles — a deployment that never passes outputSchema carries no always-on global state, and there is no per-backend acquisition block left to extract. The driver spec now drives an INLINE spawn-shaped provider over startInProcessRun, which removes the spawn/fork devDependencies (the test-only workspace cycle); plugin-level structured coverage moves to the backends' own specs (capture through the shipped plugin, mid-run backend unload, seeded fork capture). tools.md, the driver README, and both backend READMEs describe the run-scoped lifetime; the module-graph regenerates without the cycle edges.
@deepseek-ai/dsh-subagent-fork
The in-process fork subagent backend: a SubagentProvider that runs each child as a child Agent seeded with a prefix of the parent's session log — so the child inherits the parent's conversation context instead of starting fresh. Shares the run driver (startInProcessRun) with dsh-subagent-spawn; the only difference is the seed.
The seed boundary (the crux)
At the moment a subagent tool's execute runs, the parent's CURRENT turn is open and unbalanced: the log holds the assistant/message carrying this spawn's tool-call and the dangling tool/call with no tool/result yet. Seeding that raw prefix would give the child an open turn that the session constructor and the dev-mode invariants replay reject.
So the fork seeds only the balanced completed-turn prefix — the parent's log up to and including its last turn/end, excluding the in-flight turn entirely (completedTurnPrefix). Because the live log keeps seq === index, the slice is contiguous-from-0 and a valid seed. A parent on its very first (not-yet-complete) turn forks an empty seed — i.e. effectively a fresh child.
The seam this rides on: CreateAgentOptions.seed (added on dsh-agent, threaded through AgentLoop.createAgent → ctx.sessions.prepare({ seed })), the same primitive resume uses.
Capabilities
{ outputSchema: true, depthLimit: true, toolFilter: false } — identical to spawn (the depth/model/structured-output behavior is the shared driver's).
Config
| Key | Meaning |
|---|---|
providerName |
Registry name on ctx.subagents (default fork). |
See dsh-subagent-spawn for the run lifecycle, model inheritance, and depth tracking — all shared.