Teammode

Run a named team of cooperating Codex workers under one leader, with durable state on disk. This is a Codex-only workflow. It never depends on an external terminal runner - it coordinates through Codex's own collaboration tools plus a bundled state script, on ONE of two transports chosen up front: native MultiAgentV2 agents, or Codex App threads as the fallback.

When to use a team (and when to use plain subagents instead)

Use a TEAM when EITHER holds:

• the work does NOT split into perfectly isolated pieces, but doing it in parallel is clearly more convenient - members will need to see and react to each other's findings; or
• one task still needs exploration, yet its GOAL is already clear - parallel investigation under a fixed objective.

Use plain fire-and-forget subagents ($ulw / one-off spawn_agent workers) - NOT a team - when EITHER holds:

• the work IS perfectly isolated, so there is no coordination cost worth paying; or
• the GOAL is still ambiguous, where one mind should resolve direction before any fan-out.

A team buys cross-member coordination at a real overhead cost; only spend it when coordination is the thing you actually need.

Pick the transport FIRST - then tell the user

Before creating any team state, decide which transport this session can run. Inspect your active tool list and select:

1. MultiAgentV2 (preferred) - select when the flat V2 collaboration tools are ALL active: flat spawn_agent whose schema requires task_name, plus send_message, followup_task, wait_agent, list_agents, and interrupt_agent. Members are durable native agents addressed by task name / agent path (/root/<task_name>). The namespaced multi_agent_v1.* surface never qualifies as a team transport.
2. Codex App threads (fallback) - select when flat V2 is not available but the codex_app.* thread tools are (create_thread, read_thread, send_message_to_thread, set_thread_title, set_thread_archived).
3. Neither set visible - if a tool_search tool is active, search for the missing sets (e.g. spawn_agent, codex_app) before concluding: some environments defer tools behind tool search. A hit is only a lead: revalidate that the visible result is the COMPLETE, mutually compatible transport set from case 1 or 2 before selecting it. Do not combine partial hits from different transports.
4. Neither set exists - teammode cannot run here. Do NOT run init or fake a team with partial tooling. If another visible plain-subagent mechanism can independently spawn, communicate with, and observe plain workers, announce that exact mechanism and use it for non-overlapping scopes. Otherwise continue serially and report the capability limitation; never promise or imply plain subagents that this session cannot create.

Then, BEFORE running init (or instead of it in case 4), tell the user in one line what this environment provides and which route you picked:

• Teammode transport: MultiAgentV2 (flat spawn_agent with task_name).
• Teammode transport: Codex App threads (flat V2 tools not present in this session).
• Teammode unavailable: neither MultiAgentV2 nor codex_app tools exist in this session - using <visible plain-subagent mechanism> for independent scopes.
• Teammode unavailable: neither MultiAgentV2 nor codex_app tools exist in this session, and no compatible plain-subagent mechanism is available - continuing serially.

Pass the choice to init as --transport multi_agent_v2 or --transport codex_app. The transport is recorded in team.json and is IMMUTABLE for the team's lifetime: a V2 spawn failure is a V2 blocker to report, never permission to mix Codex App threads into the same team. Never probe by trial-calling tools; read your tool list, and search it with tool_search only when a needed set is not visible.

You are the leader - orchestrate, do not implement

The main session is ALWAYS the team leader; you orchestrate directly and never spin up a separate leader worker. Your job is orchestration, NOT writing product code: split the work and assign each slice, hold live situational awareness of every member, verify and QA what they deliver, relay findings between members, instruct and unblock, and synthesize the result. DELEGATE every code edit to a member - if you catch yourself editing product files while the team runs, that work was a

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