# CODEX START — Use This First

This is the shortest possible entry point for the first implementation run.

## Mandatory order

1. Read `docs/00-start/START_HERE.md`.
2. Read `docs/30-codex-optimization/CODEX_RUN_CHECKLIST.md`.
3. Read `docs/30-codex-optimization/PROMPT_DISCIPLINE.md`.
4. Read `docs/20-run-readiness/RUN_READINESS_FINAL.md`.
5. Read `docs/20-run-readiness/CODEX_TOMORROW_RUNBOOK.md`.
6. Use `prompts/codex/m14/CODEX_FIRST_DAY_MASTER_PROMPT.md` as the first Codex prompt.
7. Follow `docs/20-run-readiness/PASS_SEQUENCE_FINAL.md` exactly.
8. Select the relevant skill from `skills/` for the active pass.

## First build objective

Build the V1 foundation vertical slice:

Project → Area → Dataset metadata → Reference polygons → Predicted detections → QA/QC → GeoJSON export → Minimal UI.

Do not start with heavy AI inference, LiDAR, training, MLOps, Sentinel automation, or advanced report generation before the foundation passes.

## Pass completion rule

A pass is not done until:

- commands were run;
- tests/smoke checks were attempted;
- docs/status were updated;
- limitations are explicit;
- next pass is clear.


## M13 additions

Before implementing, Codex must respect:

- `docs/30-codex-optimization/CODEX_OPTIMIZATION_OVERVIEW.md`
- `docs/30-codex-optimization/TOKEN_BUDGET_POLICY.md`
- `docs/30-codex-optimization/SECRETS_AND_ENV_POLICY.md`
- `docs/30-codex-optimization/PARALLEL_AGENT_STRATEGY.md` when using multiple agents/worktrees
- `docs/30-codex-optimization/CODEX_SKILLS_INDEX.md`

The preferred first prompt is now:

- `prompts/codex/m14/CODEX_FIRST_DAY_MASTER_PROMPT.md`


## M14 launch controls

Before the first implementation pass, Codex must read:

- `docs/40-build-launch/SPRINT_1_SCOPE_FREEZE.md`
- `docs/40-build-launch/BUILD_SUCCESS_DEFINITION.md`
- `docs/40-build-launch/BUILD_ORDER_GRAPH.md`
- `docs/40-build-launch/CODEX_STOP_RULES.md`
- `docs/40-build-launch/MODULE_ACCEPTANCE_CRITERIA.md`

The first implementation run is Sprint 1 only. Do not implement detection, segmentation, Sentinel, LiDAR, training, AI Copilot or advanced reports during Sprint 1.