# CASAN Adoption Guide

How a downstream project adopts the CASAN governance harness. Adoption is **config +
domain only** — you never edit gate logic (H1→H7).

## Option A — DevKit install (recommended)
From a CASAN source hub or an extracted `casan-devkit` bundle:
```bash
packages/casan-devkit/install.sh --target ../my-project --project ticketing --domain "Ticketing"
```
This copies the core harness + `bin/casan` into `../my-project`, scaffolds
`apps/ticketing/domain/` from the domain-pack template, adds `.gitea/workflows/casan-ci.yml`,
and registers the project in `project-registry.json`.

## Option A2 — New production project shell

```bash
packages/casan-devkit/install.sh \
  --target ../my-project \
  --project ticketing \
  --domain "Ticketing" \
  --template nestjs-react
```

This creates a strict-TypeScript NestJS/React monorepo, health bootstrap, tests, Docker multi-stage
images, GitHub CI, a complete Domain Pack, versioned quality profile, project manifest, CASAN CLI,
harness, and manifest-driven pipeline. Existing different files are never overwritten.

## Option B — Core tarball (harness-only / CI gate)
```bash
tar -xzf casan-core-v1.0.0.tar.gz
cp -R casan-core-v1.0.0/{packages,bin,VERSION} /path/to/project/
```
Then create `apps/<project>/domain/` yourself (see `DOMAIN_PACK_GUIDE.md`).

## Option C — Docker (no install into repo)
```bash
docker run --rm -v "$PWD":/workspace -w /workspace casan-harness:1.0.0 casan gate
```
See `DOCKER_GUIDE.md`.

## After install
1. Requirement → `apps/<project>/domain/input/requirement.md` (keep the `| FR-xx |` table).
2. Golden baseline → `apps/<project>/domain/golden-runs/<artifact>.golden.txt`.
3. Corpus → `apps/<project>/domain/corpus/` (redteam + benign) for H4 scoring.
4. Requirement→code→test map → `apps/<project>/domain/traceability-map.json`.
5. Run:
   ```bash
   CASAN_DOMAIN_ROOT=apps/<project>/domain bin/casan gate     # full governance gate
   bin/casan run in.txt out.txt my_step -- <command>          # one governed step
   bin/casan reuse                                            # HARNESS_REUSE_VALID
   ```

For a manifest-enabled project prefer:

```bash
bin/casan project validate --manifest apps/<project>/domain/project.manifest.json
bin/casan pipeline --manifest apps/<project>/domain/project.manifest.json
```

## Path model (what lives where)
- **Harness code** → `packages/casan-harness/` (never edited by adopters).
- **Your domain data** → `apps/<project>/domain/` (via `CASAN_DOMAIN_ROOT`).
- **Runtime state** → `.specify/` (logs, audit, governance — created on first run).
Paths resolve via `packages/casan-harness/scripts/bash/casan-paths.sh` (marker walk-up:
`.specify` or `packages/casan-harness`), so a freshly-extracted bundle works immediately.

## Proving reuse
Two+ projects sharing the same harness package/version → `bin/casan reuse` prints
`HARNESS_REUSE_VALID ... project_count=N`. This is the evidence that the harness is genuinely
reusable, not copy-pasted. See `docs/plans/CASAN_PLAN_06_ONBOARD.md`.

## Upgrading
Re-run `install.sh` from a newer DevKit (or re-extract a newer core tarball). Your
`apps/<project>/domain/` and `.specify/` state are untouched — only `packages/casan-harness/`
+ `bin/casan` are replaced. Keep `harness_version` aligned across projects for reuse to count.