Codex
Local per-call routing and Codex Action's single-session mode.
Codex has two documented execution shapes. Local subagent dispatch accepts a model override and,
for GPT-5-family reasoning models, a separate reasoning_effort value. woostack resolves and
passes both values for each task. A Codex Action job is single-session instead: woostack resolves
one run model up front, and every tier uses that model for the job.
The local spawn receives a working directory when the host exposes one; the prompt-level worktree pin is always present. Provider exhaustion surfaces as an error. Configured fallback entries are a manual preference order on this host, not an automatically probed spawn-time chain.
For detection, the local-versus-Action boundary, per-skill instructions, and degradation rules, read the canonical Codex reference.