Codex runtime mapping

Use native read-only subagents only when authorized; the standing model-capability-router owns model and effort. Preserve simple versus complex paths, distinct exploration angles, cited synthesis and coordinator verification.

How

Explore the codebase to answer how a subsystem works. Give a senior engineer enough of a mental model to start changing it without turning the explanation into annotated source.

Choose model and effort through the standing model-capability-router and the native Codex inventory. Respect the operator's selection. If a requested model is unavailable, report that exact gap without substituting another model.

1. Assess complexity

If scope is ambiguous, state the interpretation and explore. The user can redirect.

• Simple: one module, small utility, or narrow question. Do not spawn explorers. If native delegation is authorized and useful, use one read-only explainer with references/explainer-prompt.md; otherwise inspect and explain directly. Then go to step 4.
• Complex: a subsystem spanning files or services, a cross-cutting feature, or a full architecture overview. Continue to step 2.

When in doubt, take the simple path.