Subagent Orchestration

Subagent Orchestration

Use when Codex multi_agent_v2 delegation can save context, run work in parallel, reduce uncertainty, or add independent verification. Target multi_agent_v2 only; if unavailable, say this skill requires it rather than falling back to older multi_agent calls.

Bias and Boundaries

Default to delegation for deep reading, uncertain call paths, implementation branches, debugging, docs/API lookup, browser reproduction, tests, review, or long-running commands. Keep local only if the next root decision needs 1-2 quick checks first.

The root thread remains user-facing integrator: plan owner, conflict resolver, final verifier, and stop/go decision maker. Do not delegate user-visible judgment or forward raw child transcripts; require compact receipts and synthesize them yourself.

Spawn Checklist

Before each spawn_agent call:

1. Split independent work into narrow agents; use leads only for bounded branches with internal subtasks.
2. Assign ownership: files/modules, read-only vs write, allowed commits, done criteria, evidence, receipt shape.
3. Prevent collisions: never give two writers the same files without isolated branches/worktrees and an integration plan.
4. Warn parallel siblings: Another agent is concurrently working on <task> in <files>. Avoid that area; stop and report overlap/dependencies.
5. Use fork_turns:"none" by default; bundled agents read needed context from the first message.
6. Pass the matching reasoning_effort explicitly; avoid model overrides unless requested or clearly required.

Parallel Safety

Maximize safe parallelism without losing attribution:

• Fan out read-only mapping/research/debug/test probes for independent questions.
• Parallelize writers only by distinct ownership or isolated branches/worktrees.
• Serialize dependent writes; finish and verify API/shape A before dispatching B.
• Pipeline while waiting: prepare briefs, verify receipts, update plans, or launch another independent agent.
• Reviewers may inspect completed patches while unrelated work continues.

Commit Discipline

For repository-changing work, commit at stable verified checkpoints unless user/repo instructions prohibit it.

• Default writer brief: commit after owned validation passes; include hash in receipt.
• Keep commits focused and attributable; never commit broken tests, conflicts, secrets, generated junk, or unrelated formatting.
• Require git status, relevant validation, changed-file summary, and commit hash/reason-no-commit.
• If several writers run in parallel, isolate them or have them stop before commit so the root integrates sequentially.

Agent Types

Use custom agent_type only when present; otherwise stop and report unavailable role. Exact names/default efforts:

Valid spawn_agent Examples

Read-only probe:

{"tool":"spawn_agent","args":{"task_name":"map_auth_flow","agent_type":"code_mapper","reasoning_effort":"low","fork_turns":"none","message":"Read-only. Trace auth flow from entry to side-effect boundaries. Return ordered call path, key files/symbols, risky branches, and confidence gaps. Do not edit files."}}

Parallel non-overlapping writer/tester:

{"tool":"spawn_agent","args":{"task_name":"auth_middleware_change","agent_type":"implementation_engineer","reasoning_effort":"low","fork_turns":"none","message":"Own only auth middleware files. Another agent is concurrently working on auth tests; avoid tests and stop if overlap appears. Implement the middleware change, run relevant validation, commit after tests pass, and return changed files, validation summary, commit hash, and risks."}}

{"tool":"spawn_agent","args":{"task_name":"auth_tests_change","agent_type":"test_automator","reasoning_effort":"medium","fork_turns":"none","message":"Own only auth test files. Another agent is concurrently working on auth middleware; avoid middleware and stop if overlap appears. Add focused regression coverage, run relevant validation, commit after tests pass, and return changed files, validation summary, commit hash, and risks."}}

Patch review:

{"tool":"spawn_agent","args":{"task_name":"review_patch","agent_type":"reviewer","reasoning_effort":"high","fork_turns":"none","message":"Review the current change for correctness, regressions, security, and missing tests. Findings first with file/line evidence. Do not edit files."}}

Runtime Discipline

• Use list_agents for complex trees, wait_agent for mailbox updates, send_message for clarifications, followup_task for new work on an existing agent, and close_agent when a branch/probe is done.
• Track agent ownership, commit permission, landed commit hashes, unresolved dependencies, and which receipts are still missing.
• Close disposable organizers after their plan; do not let any lead own the whole conversation.

Required Agent Receipt

Require lead and leaf agents to return:

• agents spawned and why, if any
• conclusion or patch summary
• changed files, if any
• exact validation commands and pass/fail status
• commit hash(es), or explicit reason no commit was made
• unresolved risks/conflicts
• exact next action needed from the parent

Guardrails

Do not delegate urgent blocking work, user-visible decisions, or unscoped ownership. Do not spawn multiple writers for the same files without isolation. Do not optimize for parallelism at the cost of causality: performance experiments and risky behavior changes usually need one attributed change at a time. Do not let agents commit unrelated work or commit before validation.