Skill Router

Use this skill to make Codex routing environment-aware instead of guess-based.

Quick Start

1. Classify the task into a lane:

• direct
• broken
• build
• operate
• review
• plan

1. Run scripts/scan_codex_inventory.py to inspect local skills, plugins, and MCP servers.
2. Match the task against the most specific local capability first.
3. Return a compact recommendation using the routing contract in references/routing-contract.md.

Lane Selection

| Lane | Examples | Default Reasoning | Default Thinking | |------|----------|-------------------|------------------| | direct | trivial read, one command, factual answer | fast | none | | broken | bug, regression, crash, failing test, broken build | standard | think | | build | new feature, component, integration, workflow | standard | think | | operate | refactor, automate, configure, document, deploy | standard | none | | review | code review, risk review, security review | standard | think-hard | | plan | broad, ambiguous, multi-stage, scope decisions | frontier | ultrathink |

Escalate to frontier reasoning + ultrathink for: production incidents, auth/permissions changes, architecture decisions where rollback is expensive.

If a task spans multiple lanes, choose the first critical lane and note the downstream chain.

Capability Resolution

Prefer, in order:

1. repo instructions already in force
2. local Codex skills
3. enabled plugins
4. configured MCP/tool surfaces
5. direct execution

Rules:

• prefer one strong local capability over a long chain
• prefer the most specific capability over the most famous one
• fall back to direct execution if no strong local match exists
• do not search the internet for skills by default
• do not auto-install anything silently

Inventory Scan

Use the bundled script:

bash
python3 scripts/scan_codex_inventory.py
python3 scripts/scan_codex_inventory.py --query deploy
python3 scripts/scan_codex_inventory.py --json

Use the inventory scan when:

• you need to know which local capability is actually present
• multiple possible skills might match
• the task mentions a tool or platform and you want to confirm availability

Output Contract

Always return:

• lane
• chosen capability or fallback
• reasoning tier: fast, standard, or frontier
• verification plan
• short notes only if needed

See references/routing-contract.md for the canonical shape.

Named Chains (Optional)

If AGENTS.md declares saved chain sequences, check them BEFORE computing fresh from the lane tables. Match by substring on the user's prompt; first match wins.

yaml
# in AGENTS.md
chains:
  - name: ship-feature
    when: ["ship the feature", "lets implement"]
    chain: writing-plans → frontend + db
    thinking: think

Per-step models / agents resolve from the lane tables unless chain.model or chain.thinking overrides globally, or steps[].model overrides per step.

Dispatch Protocol — Per-Step Model Enforcement

When a chain step needs a different model than the parent session, dispatch that step as a Codex sub-task with model: set explicitly. Steps that match the parent model run inline.

For each step in the chain:
  IF step.model == parent_model AND not parallel-fan-out:
      → run inline
  ELSE:
      → spawn sub-task with model=<step.model>, agent=<step.agent>
  Parallel steps (`+`) launch concurrently.

Thinking Depth

Each lane row carries an optional Thinking value: none / think / think-hard / ultrathink. Pre-pend the keyword to the dispatch prompt to allocate extended-thinking budget. Production incidents and architecture decisions default to ultrathink; mechanical work to none.

Codex-Specific Notes

• this skill is local-first
• this skill is for routing and orchestration, not governance
• for enterprise governance, policy, and proof of judgment, use Sentigent instead of expanding this skill into a control plane

Resources

scripts/

• scan_codex_inventory.py: inspect installed local Codex skills, enabled plugins, and configured MCP servers

references/

• routing-contract.md: required output shape for recommendations
• product-boundary.md: product boundary and audience definition for the Codex version