Codex Orchestration

Bring models like Claude Fable 5 into Codex, give each model a role, and let Codex coordinate the work.

What is it?

Codex Orchestration adds three simple roles to a Codex task:

• Planner creates the plan and improves it after feedback. It is optional; when omitted, your current Codex model plans.
• Advisor reviews the plan, finds important gaps, and approves it when it is ready. It is optional.
• Executor implements the approved plan. It is required for setup.

The model selected for the Codex task remains in charge. It passes work between the roles, checks every result, and gives you the final answer.

How it works

                         YOUR TASK
                             |
                             v
                  CODEX COORDINATES THE WORK
                             |
                             v
               PLANNER CREATES THE FIRST PLAN
              Fable 5, another model, or Codex
                             |
                             v
                    ADVISOR REVIEWS IT
                       finds real gaps
                             |
                   needs work? -- yes --+
                             |            |
                            no            v
                             |      PLANNER IMPROVES IT
                             |            |
                             +<-----------+
                             |
                       PLAN APPROVED
                             |
                             v
                  EXECUTORS IMPLEMENT IT
                             |
                             v
                    CODEX TESTS & DELIVERS

Planner and Advisor can work through several revisions. Codex stops as soon as the Advisor returns PLAN_APPROVED, with a safety limit of five reviews. If approval is not reached, execution stops and Codex shows you the latest plan and unresolved issues.

Why use it?

• Bring Fable 5 or another compatible model into Codex.
• Use different models for planning, review, and implementation.
• Get a stronger plan before code changes begin.
• Run independent implementation work in parallel—up to 2x faster on suitable tasks.
• Move repeatable work away from the root model and potentially hit premium-model limits about 40% less often.

Results depend on the models, task, context, retries, and available parallel work. The speed and limit figures are targets, not guarantees.

Install

codex plugin marketplace add Cjbuilds/Codex-Orchestration
codex plugin add codex-orchestration@codex-orchestration

Start a new Codex task after installation. Setup requires Python 3.11 or newer.

Quick start

Use Fable 5 to plan, Sol to advise, and Luna to implement:

/codex-orchestration setup planner: Claude Fable 5 High, advisor: GPT-5.6 Sol High, executor: GPT-5.6 Luna Extra High

Or let your current Codex model plan and use Fable 5 only as Advisor:

/codex-orchestration setup advisor: Claude Fable 5 High, executor: GPT-5.6 Luna Extra High

After setup, start another new task and use Codex normally. The saved workflow applies automatically.

Fable defaults to High. You can choose Low, Medium, High, XHigh, or Max. Ultra is accepted as an alias for Max because Claude Code does not expose a separate Ultra effort.

Fable 5 uses the official Claude Code CLI and a compatible first-party Claude login. You do not need to add an Anthropic API key to Codex.

Choose your roles

/codex-orchestration setup planner: <model and effort>, advisor: <model and effort>, executor: <model and effort>

• Omit planner to use the current Codex model as Planner.
• Omit advisor when you do not want plan review.
• executor is required.
• Planner and Advisor must use different configured model routes so the review is independent.

Role labels are literal. A model after planner: plans; a model after advisor: reviews; a model after executor: implements. Codex must never move a model to a different role because that model was used differently in an older plugin version. If you specify Planner and Executor but omit Advisor, the workflow has no Advisor.

Examples:

/codex-orchestration setup planner: Claude Fable 5 High, advisor: GPT-5.6 Sol High, executor: GPT-5.6 Luna Extra High

/codex-orchestration setup planner: GPT-5.6 Sol Extra High, advisor: Claude Fable 5 High, executor: GPT-5.6 Luna Extra High

/codex-orchestration setup executor: GPT-5.6 Luna Extra High

Bring another model into Codex

Models already available through Codex can be assigned directly. A model from another provider needs an existing authenticated, compatible provider and a Codex custom-agent role.

Ask the plugin to create a project or personal role:

/codex-orchestration create project role:
name: researcher
model: <exact-model-id>
provider: <configured-provider-id>
effort: high
job: gather evidence and cite sources

Project roles live in .codex/agents/. Personal roles live in ~/.codex/agents/ and can be reused across projects. Codex previews role files before creating them.

Fable 5 is the bundled cross-provider exception and can be used directly as Planner or Advisor. The plugin never creates provider accounts, credentials, or protocol compatibility.

Use it with Codex Goals

Create a Codex Goal normally, then tell Codex to use the saved workflow until the Goal is complete. Codex still owns Goal state, permissions, integration, and verification; the plugin only guides which models perform each role.

Useful commands

/codex-orchestration status
/codex-orchestration status --require-effective
/codex-orchestration setup planner: Claude Fable 5 High, advisor: GPT-5.6 Sol High, executor: GPT-5.6 Luna Extra High
/codex-orchestration disable

disable restores the routing values that existed before setup. It does not delete user-owned custom roles.

Important limits

• Codex remains the root orchestrator and final authority.
• Planner and Advisor report only to Codex; they do not contact each other or Executors directly.
• The workflow reserves Fable planning tools for the root Codex model by policy. Current MCP calls do not identify their caller, so this caller boundary is instruction-enforced; the bridge itself still disables tools, edits, and session persistence.
• Advisor approval is a planning gate, not a guarantee that implementation will succeed.
• Direct model routes inherit the root provider. Other providers must already be configured and authenticated.
• The plugin never creates credentials or bypasses permissions and approvals.
• Codex decides when delegation or parallel work is useful.
• If you say no subagents, Codex must not delegate.

Technical details are in providers and models.

Update

codex plugin marketplace upgrade codex-orchestration
codex plugin add codex-orchestration@codex-orchestration

Version 0.5.1 or newer is required for reliable Planner assignment. It has a distinct release identity so Codex replaces the affected Advisor-only 0.5.0 cache instead of reusing it. After the two update commands, confirm codex plugin list --json reports 0.5.1 or newer, then start a new task; a task that already loaded the old skill cannot refresh its instructions in place.

If the version stays old or marketplaceSource.sourceType is local, Codex is pointed at a local checkout rather than the GitHub marketplace. Run /codex-orchestration disable first if a saved policy is active, then remove the plugin and that marketplace registration, add Cjbuilds/Codex-Orchestration again, and reinstall. This does not delete the local source checkout.

Before downgrading to a version older than Planner support, run /codex-orchestration disable with the current version first.

Uninstall

First run:

/codex-orchestration disable

Then remove the plugin:

codex plugin remove codex-orchestration@codex-orchestration
codex plugin marketplace remove codex-orchestration

Review and remove any user-owned custom roles separately.

Development

python3 -m pip install -r requirements-dev.txt
python3 -m compileall -q plugins tests scripts
python3 -m ruff check plugins tests scripts
python3 -m unittest discover -s tests -v
python3 tests/plugin_lifecycle_smoke.py
python3 scripts/release_check.py

See the production-readiness audit, security policy, and release process.

License

MIT