# SPEC.md — Engineering rules for G.U.I.D.E.

This file defines the **non-negotiable process rules** for changing this codebase.
They exist to stop the kinds of drift and breakage we have actually hit while
iterating. Read this before opening a change; the rules here are enforced by the
sanity suite and the git pre-commit hook.

> **Sister docs:** `CLAUDE.md` describes the architecture; the `openspec/`
> workflow describes *what* to build. **SPEC.md describes how every change must
> be made and verified.**

---

## 1. Definition of Done (every change)

A change is not complete until **all** of the following hold:

1. **Sanity tests pass** — `python -m pytest tests/test_sanity.py -q` is green.
   No code may be committed while sanity tests fail (enforced by the pre-commit
   hook — see §4).
2. **The “How To Guide” tab is in sync** — see §2.
3. **Docs reflect the change** — if you changed architecture, tabs, endpoints,
   env vars, or invariants, update `CLAUDE.md` (and `README.md` if user-facing).
4. **No secrets added** — API keys/tokens live only in the git-ignored `.env`.
   Never paste them into source, tests, or commit messages.

## 2. The “How To Guide” tab MUST be kept in sync

The first tab in `ui/app.py` (`📖 How To Guide`) is the user's onboarding doc.
**Any UI change that affects what the user sees or does must be reflected there**,
specifically:

- Adding, removing, or renaming a **tab** → update the *“What Each Tab Does”*
  table (and the *Step-by-Step Flow* table if it changes the main flow).
- Adding or changing a **user-facing feature** (e.g. PDF export, the redaction
  reveal panel, the privacy audit) → describe it in the relevant tab row and,
  if it touches privacy, in the *“Your Privacy”* section.
- Changing the **privacy behaviour** → keep the *“Your Privacy”* section honest.

This rule is partially **automated**: `test_how_to_guide_lists_every_tab` fails
if any user-facing tab is not mentioned in the How To Guide. The judgement calls
(feature descriptions, privacy wording) are on the author — keep them current.

## 3. Sanity test suite

Location: `tests/test_sanity.py`. It is **fast** (no ML checkpoints, no spaCy
model, no Anthropic API, no network) and covers:

| Check | Guards against |
|-------|----------------|
| Gradio app builds (`build_app()`) | event/component wiring, output-count, scope bugs |
| API models + routes import & validate | request/response schema breakage |
| `RedactionResult.spans` contract | the redaction-reveal data contract |
| Redaction-reveal / audit-log render helpers | the two privacy features silently breaking |
| PDF export produces a real `%PDF-` file | the export feature breaking |
| Friendly LLM-error mapping | overloaded/rate-limit/timeout → user-friendly message |
| How To Guide lists every tab | the guide drifting out of sync (see §2) |

**When you add a feature, add a sanity check for it here** if it is cheap to
verify without heavy dependencies. Keep the whole suite under ~15 seconds.

The deeper unit tests under `tests/<module>/` (classifier, ner, agent, privacy,
etc.) are **not** part of the commit gate — run them with `pytest tests/` when
you touch those layers.

## 4. Enforcement — git pre-commit hook

A pre-commit hook runs the sanity suite and **blocks the commit if it fails**.

Install it once after cloning (idempotent):

```bash
bash scripts/install-hooks.sh
```

This copies `scripts/hooks/pre-commit` into `.git/hooks/` and marks it
executable. The hook runs `tests/test_sanity.py` in the project `.venv`
(falling back to `python3`). To bypass in a genuine emergency only:
`git commit --no-verify` — but the change is then **not** Done per §1.

## 5. Checklist to paste into a PR / change description

```
- [ ] Sanity tests pass: pytest tests/test_sanity.py -q
- [ ] How To Guide tab updated (tabs / features / privacy wording)
- [ ] CLAUDE.md / README.md updated if architecture or behaviour changed
- [ ] No secrets added to source or commits
- [ ] Added a sanity check for any new user-facing feature (if cheap)
```