# M13 Handoff Summary — Codex Optimization Pack

M13 adds the final layer intended to improve tomorrow's Codex execution quality.

## Added

- Codex optimization overview.
- Codex run checklist.
- Prompt discipline rules.
- Token/context budget policy.
- Secrets and environment policy.
- Parallel agent strategy.
- Codex skills index.
- Reusable skills under `skills/`.
- M13 day-one optimized master prompt.
- Pass completion report prompt.
- Updated readiness checks for M13 assets.

## Why this matters

M12 made the repository run-ready. M13 makes the repository easier for Codex to execute correctly without wasting context, drifting from contracts, leaking secrets, or making undocumented architecture choices.

## Recommended next action

Use:

- `prompts/codex/m13/DAY_1_OPTIMIZED_MASTER_PROMPT.md`

for the first serious Codex build run.