# CLAUDE.md

Scope: the **`@trek/server`** workspace. See the repo-root `CLAUDE.md` for the monorepo picture and the philosophy. This file holds the server's commands, invariants and pitfalls; the code and `src/nest/README.md` hold the inventory.

## Commands (run from `server/`)

```bash
npm run dev               # scripts/dev.mjs: tsc -w then node --watch dist/index.js (server on :3001)
npm run build             # scripts/build.mjs — emits even on type errors (see below)
npm run typecheck         # tsc --noEmit — the real type gate
npm run typecheck:tests   # tsc over tests/ — CI runs this too; vitest green does NOT mean typed mocks compile
npm run lint              # eslint --fix
npm run lint:check        # eslint, no fix (CI)
npm run test              # vitest run; also test:unit / test:integration / test:ws / test:e2e
npm run test:coverage     # istanbul coverage; per-domain ratchet over src/nest/**
npm run gen:plugin-facts  # regenerate the plugin-protocol tables into plugin-sdk/ + shared/
npm run check:plugin-facts # CI gate — fails if the generated copies drifted
npm run gen:db-types      # regenerate the Kysely table types in src/db/kysely/ from the migrated schema
npm run check:db-types    # CI gate: fails when src/db/kysely/ no longer matches the migrations
node scripts/coverage-thresholds.mjs  # after test:coverage — prints the ratchet block for vitest.config.ts
npm run db:call-graph -- --sync --tx [--domains nest/days,…]  # sync DB-touching methods + transaction sites (exit 1 if any)
npm run lint:size         # no file in src/ or scripts/ past 1000 lines, longer ones only shrink (CI gate)
npm run lint:boundaries   # import cycles and cross-domain reach-ins may only shrink (CI gate)
npm run lint:dialect      # SQLite-only SQL spellings under src/ may only shrink (CI gate)
npm run contracts:dto-open # open shapes in the createZodDto schemas may only shrink (runs in the unit tests)
```

**`lint:boundaries`** (`scripts/import-boundaries.mjs`) parses every import under `src/` and holds five lists in `scripts/import-boundaries-baseline.json`: load-time file cycles (type-only and lazy imports, and the MikroORM entity relations, do not count), dependencies between two `nest/<domain>` folders that already depend on each other, shared-kernel files (`nest/common`, `nest/database`, `nest/app-config`) importing a domain, a domain importing another domain's internals, and `src/db` importing `src/nest`. A domain's public surface is its `*.module`, `*.service`, `*.guard`, `*.decorator`, `*.types`, `*.interface`, `*.contract`, `*.constants` and `*.logger` files plus the short `PUBLIC_FILES` list in the script; anything else is an internal. A new entry fails the check, and so does a baseline entry that no longer occurs, so the fix lands with `npm run lint:boundaries -- --update`, which drops such entries and never adds one.

**`contracts:dto-open`** (`tests/unit/contracts/dto-open-shapes.test.ts`, wrapped by `scripts/dto-open-shapes.mjs`) finds every `export class X extends createZodDto(...)` under `src/`, imports it and counts the open shapes (loose object, record of unknown, `z.unknown()`/`z.any()`, `z.custom()`) in the schema the Zod pipe validates, with shared's `contracts:open` walk. Each DTO class is held to its entry in `scripts/dto-open-shapes-baseline.json`, and a new one may hold none, whatever its schema is called and wherever it is declared. A `createZodDto` call that is not an exported class, or two DTO classes with one name, fail the check. After narrowing a schema, `npm run contracts:dto-open -- --update` lowers the baseline (it never raises or adds an entry). It needs `shared/` built.

**`lint:size`** (`scripts/size-lint.mjs`) counts a line longer than 120 columns once per 120 columns it spans, so joining lines does not make room. Files that were already longer are held at their length in `scripts/size-baseline.json`; a file that needs to grow past its entry is split by concern instead. An entry above what its file holds now, or for a file that is gone, fails as well, so after a split `npm run lint:size -- --update` lowers the baseline in the same change (it never raises or adds an entry).

Single test: `npx vitest run tests/unit/nest/weather.controller.test.ts`, or `npx vitest run -t "returns 401 without cookie"`.

**Build emits even with type errors** (`scripts/build.mjs` catches `tsc` failures and warns). `npm run build` succeeding does **not** mean the code typechecks — run `npm run typecheck`.

**`lint:dialect`** (`scripts/dialect-lint.mjs`) reads every string and template literal under `src/` (comments do not count) and every `.insertId` read, and counts the SQLite-only spellings per file and rule: `INSERT OR IGNORE`/`REPLACE`, `datetime()`/`julianday()`, `strftime`, `json_extract` and its siblings, `GLOB`, `last_insert_rowid`, `AUTOINCREMENT`, a `PRAGMA` statement outside the `src/db/*.ts` lifecycle files and the migrations, and `||` concatenation in SQL. The counts are held to `scripts/dialect-baseline.json`; a new hit fails, and so does an entry above what its file holds now, so the change that removes one runs `npm run lint:dialect -- --update` (it never raises or adds an entry). `src/db/dialect/sql-functions.ts` is not scanned, and neither are the migrations up to `FROZEN_MIGRATIONS_THROUGH` in the script; a newer migration is held to the DML rules, while its DDL stays engine specific.

## Architecture invariants

Nest owns everything. Every domain is a DI module under `src/nest/<domain>/` (`controller` + `service` + `module`, registered in `src/nest/app.module.ts`); business logic lives in the injectable `.service.ts`, pure halves in `.helpers.ts`, SQL in a `.repository.ts` where one exists. There is no legacy service layer — ESLint errors on any `services/` import. **`weather/` is the reference module shape; `collections.controller.ts` is the reference for body validation and enumeration-safe access checks.**

- **`src/bootstrap.ts` — `buildApp()`** is the single builder for production and the test harness. Everything on the raw Express instance (global middleware, uploads, discovery metadata, statics, the named `jsonParser`/`urlencodedParser` wrappers) is registered **before `app.init()`**, because Nest throws `NotFoundException` on unmatched routes and nothing after init is reachable. The wrappers exempt `/mcp` so the MCP SDK reads the raw stream — **never `@Body()` a `/mcp` route**. Don't add routes to that pre-init shell; it bypasses every global guard, interceptor and filter.
- **Realtime**: `/ws` is a Nest gateway in `src/nest/realtime/`. Inject `RealtimeService`; `src/websocket.ts` is a re-export stub for old call sites. Trip mutations forward `X-Socket-Id` so the originating client doesn't echo its own change.
- **MCP**: `src/nest-mcp/` is the decorator/registry layer (`@McpController`/`@Tool`/`@Resource`/`@Prompt`; see its `README.md`); tools live in `<domain>.mcp.ts` files beside each module; the HTTP transport is `src/nest/mcp-transport/`; `src/mcp/` holds process-wide state only (scopes, session manager, boot policy). Every tool invocation writes an audit row through the registry's `onInvoke` seam. MCP tools are adapters over the same services and permission checks as REST — a change on one side lands on the other in the same change.
- **Scheduling**: `src/nest/scheduling/` (`CronRegistrarService`) is the one way to schedule a cron. Jobs are `*.job.ts` providers in their owning domain. The registrar refuses to schedule under `NODE_ENV=test` (an integration test pins it). **Never use a `@Cron` decorator** — it bypasses that gate.
- **Plugins** (`src/nest/plugins/`): the child-process runtime (`supervisor/`, `runtime/plugin-host-entry.ts`, `protocol/envelope.ts`) is **intentionally not Nest** — it is the security boundary. `host/rpc-host.ts` registers an RPC method at spawn only if the plugin holds the unlocking permission (registration = authorization). Install-time gates live in `install/`; the manifest's `trek` version range fails closed, and `TREK_PLUGINS_IGNORE_TREK_RANGE` downgrades that to a warning. The protocol tables in `protocol/envelope.ts` (+ `src/plugin-event-sink.ts`) are **generated** into `plugin-sdk/` and `shared/` — run `gen:plugin-facts` after touching them and commit the output. `runtime/egress-policy.ts` is a hand-kept mirror guarded by a parity test in `plugin-sdk/`; change both sides together.
- **Storage**: `src/nest/storage/` is the upload driver abstraction (local / S3 / mirror behind one interface, with an admin surface and a usage job). Domain services never touch the filesystem or the S3 SDK directly.
- **DB** (`src/db/`): `better-sqlite3`, WAL, FK on. `database.ts` only holds the connection and applies pragmas. It does not build a schema, and importing it opens nothing (the first reader does). The connection's lifecycle belongs to the `DatabaseLifecycle` provider (`nest/database/database-lifecycle.service.ts`): `buildApp()` opens it through `open()` (which binds the ORM to later swaps and runs the schema bootstrap below), the shutdown closes it through `close()`, and a restore or the demo reset swaps the file only through the database backup port, `DATABASE_BACKUP` (`nest/database/database-backup.interface.ts`; the SQLite implementation is `nest/backup/sqlite-database-backup.ts`: `VACUUM INTO` snapshot, close, atomic file swap, `reopen()`). The port works on `DatabaseLifecycle.file`, the one resolved path (`TREK_DB_FILE` or `data/travel.db`), and a snapshot that fails fails the backup rather than archiving the live file. `MaintenanceRepository` is provided only by `MaintenanceModule`'s factory and injected everywhere else; no consumer constructs it. A provider that has to follow every reopen (the demo reset job saves the first demo baseline after a restore's re-bootstrap seeded the example trips) registers with `DatabaseLifecycle.onReopened()`, which runs after the reopen's schema bootstrap; a listener contains its own failures, since one that throws fails the reopen. MikroORM's migrations (`db/migrations/`) are the only schema source, **including for tests**: the hand-kept `schema.ts`/`migrations.ts`/`seeds.ts` builders and the parity test that guarded them are gone. Seeding is the MikroORM seeders in `db/seeders/`, applied by `db/orm.ts` from `buildApp()` before anything reads. An install the retired positional runner migrated (a `schema_version` row, no `mikro_orm_migrations` rows) is baselined by `db/legacy-baseline.ts`: the migrations whose `Legacy migration step N` docstring is ≤ its version are recorded as executed (never replayed) in the same transaction as the migrator run, while the baseline migration itself still runs first, as the legacy runner's `createTables()` did on every boot; anything it cannot map refuses the boot. Before a boot applies pending migrations to a file database that holds anything, `db/pre-migrate-snapshot.ts` writes a `VACUUM INTO` copy next to it (`pre-migrate-<schema>-<time>.db`, `<schema>` being `legacy-<schema_version>` or the last recorded migration's timestamp; the newest `TREK_DB_PRE_MIGRATE_SNAPSHOT_KEEP` stay) and the newer-database refusal names the matching copy; a copy that cannot be written refuses the boot unless `TREK_DB_PRE_MIGRATE_SNAPSHOT=false`. It is off under `NODE_ENV=test` unless a suite sets that variable to true, and a restore's re-bootstrap skips it (the archive is the copy). After the migrator, `db/email-case-index.ts` creates the case-insensitive unique index on `users.email` that its migration had to defer on an install holding two accounts whose emails differ only in case (flag `email_case_index_pending`). `db/orm-driver.ts` binds the ORM to that same connection instead of opening a second one — with `:memory:` under test, a second connection is a second, empty database. Kysely statements (`this.kysely<...>()`) type against `DB` from `db/kysely/db.ts`, narrowed with `Pick<DB, 'trips' | 'days'>`; those files are generated from the migrated schema by `scripts/generate-db-types.ts`, so a migration that adds or changes a column is followed by `npm run gen:db-types`, never by a hand-written table interface. Every read and write goes through a repository in `db/repositories/` (each extends the shared `TrekRepository` base in `db/repositories/_shared/`, which validates the request context before delegating to MikroORM) and, for multi-statement writes, `UnitOfWork.transactional(...)` (`nest/database/unit-of-work.ts`, provided by the global `OrmModule`) — there is no `DatabaseService`/`DatabaseModule` to inject any more. Entrypoints outside an HTTP request — an MCP tool call, a plugin RPC dispatch, a WebSocket message, a cron job, boot-time seeding, a backup restore — open one explicitly with `withRequestContext()` (`nest/database/request-context.ts`), since only the pathless `mikroOrmRequestContext` middleware `buildApp()` mounts (with `@mikro-orm/nestjs`'s own `registerRequestContext` turned off in `app.module.ts`, UPLOADS-P16) forks an `EntityManager` per HTTP request. `NODE_ENV=test` ⇒ isolated `:memory:` DB per vitest worker, opened from a snapshot `tests/global-setup.ts` migrates once per run; `TREK_DB_FILE` ⇒ explicit file DB (Playwright harness).

## Rules for new code

- **Thin controller → injectable provider.** Never resurrect a plain function-module service; don't grow god services — split a domain into several modules when it outgrows one class (trips and auth already are).
- **Inject, don't reach for module globals.** No imports of the global `db` proxy from `nest/` layers at all any more — the last production importer converted onto a repository, and the export now survives only so ~190 test files' `vi.mock('…/db/database', …)` factories keep typechecking; no new code depending on the `ws` singleton or event-sink globals. There is no `DatabaseService` to inject either — take the repository(ies) you need plus `UnitOfWork` for transactions. Modules must be importable without side effects.
- **Transactions are not optional.** Multi-statement writes go in `await this.uow.transactional(async () => …)` (`UnitOfWork` from `nest/database`, provided by the global `OrmModule`); never hand-roll `BEGIN`/`COMMIT` and never call `db.transaction()` (the Phase 1 async sweep removes it). Every DB-touching method is `async`; `@typescript-eslint/no-floating-promises` and `no-misused-promises` are errors, so an unawaited call or a `Promise` in a condition fails lint. Bind values with `?`; identifiers only via a literal allow-list. In `src/db/repositories/` and `src/db/seeders/`, ESLint refuses raw SQL in any spelling: `raw()`, the `sql` tag, and SQL text handed to `execute`/`run`/`all`/`get`. Build the statement with the query builder; `MaintenanceRepository`, `AdminSeeder` and `CategorySeeder` are the named exceptions in `eslint.config.mjs`, and `tests/unit/eslint-rules/restricted-syntax-selectors.test.ts` pins how many SQL strings each still holds, so they can only lose SQL, never gain it. An insert that needs the new id reads it with `.returning('id')`: `InsertResult.insertId` is SQLite's `last_insert_rowid` and undefined on Postgres, and ESLint refuses it in `src/db/repositories/` and `src/db/seeders/`.
- **Migrations are append-only.** A migration is identified by its class name in `mikro_orm_migrations`, and files sort by the timestamp in that name. Never rename or delete one that has shipped, and never edit its body; add a new one. No env interpolation in SQL. (The old positional `schema_version` array and the hand-kept `db/migrations.ts` test builder are both gone; the numbered migrations are the only schema history, for tests too.) A new foreign key comes with an index that leads with its column(s), or deleting the parent scans the child table (a partial index counts only when its WHERE clause is `IS NOT NULL` on those columns); `tests/unit/db/foreign-key-indexes.test.ts` fails on one without.
- **Every write endpoint validates** through the Zod pipe with a schema from `@trek/shared` — no `Record<string, unknown>` + ad-hoc checks. Also verify every referenced id exists and belongs to the same trip.
- **Every outbound `fetch`** gets a timeout, a response-size cap and boundary validation: no `as`-casting provider responses, no silent `catch → null`. User-influenced URLs go through the SSRF guard. Never fall back to another user's API key. ESLint requires an init with a `signal` on `fetch`, `safeFetch`, `safeFetchFollow` and `safeFetchAdminConfigured` alike, or a literal `timeoutMs` in the options object of `safeFetch`/`safeFetchFollow`; an init spelled `undefined`, `null` or `void 0` counts as none (`safeFetchLlm` takes `LLM_TIMEOUT_MS` inside). Behind that, the guarded wrappers (`utils/ssrfGuard.ts`) cap every body at `DEFAULT_MAX_RESPONSE_BYTES` (64 MB) and, for a call without a signal, wait `DEFAULT_RESPONSE_TIMEOUT_MS` (30 s) for the headers. Pass a tighter `maxBytes` when you buffer a small answer, `timeoutMs` for a deadline over the whole exchange, and `maxBytes: null` only where the body is streamed on or counted by the caller (`pipeAsset`, the doc-sync transfers, the Ollama pull).
- **Fail closed.** Unrecognized flag values mean OFF; sandbox/permission opt-outs refuse in production; never pick a less-safe path based on the *absence* of a file. GET handlers must not write.
- **Don't fork canonical paths.** Auth verification is `verifyJwtAndLoadUser` (with the `password_version` gate) — reuse it.
- **Money**: integer cents; largest-remainder splits (`BudgetService.splitEqualShares` is the reference); FX frozen at entry; explicit flags, never sentinel values; custom splits must reconcile to zero before persisting.

## Configuration (app-config)

**Never read `process.env` in `src/**`** — ESLint errors on it. All env access goes through `src/app-config/`:

- Nest classes inject a boot-stable namespace token from `src/nest/app-config/` for values frozen per app build, or use `RuntimeEnvService` / `readEnv()` for runtime-toggled values (DEMO_MODE, NODE_ENV, OIDC_*, …) that tests mutate mid-lifetime.
- Everything else calls `readEnv()` — live, uncached, per call.
- Validation is fail-fast at boot only (`boot-validate.ts`, imported by `index.ts` right after dotenv): malformed values abort startup; unset/blank defaults. Never wire validation into `buildApp()` or `ConfigModule.forRoot`, and never `cache`/snapshot a runtime-toggled value (it breaks the env-mutating tests).
- Booleans go through `parseBool` (true/1/on/yes vs false/0/off/no). Everything else pins its exact legacy coercion — quirks and the ESLint exemption list are in `src/app-config/README.md`.

## Cross-cutting pieces

- **`src/nest/common/`**: the global exception filter (error envelope), the Zod validation pipe, the idempotency interceptor (`X-Idempotency-Key` replay), and `validate-route-guards.ts` (boot-time ratchet refusing any public route not on its allow-list).
- **Auth is default-deny**: the global auth guard and the MFA policy guard run as `APP_GUARD`s, followed by the managed-install guard (`managed.guard.ts`), which refuses the routes a centrally administered install withholds from its own admin — it runs last so strangers still get a 401, never a route-revealing 403. Routes opt out with `@Public()`/`@OptionalAuth()`. The global guard stands down for routes declaring their own guard chain, so `@UseGuards(JwtAuthGuard, TripAccessGuard)` + `@RequirePermission` stacks work. Session is a cookie (`trek_session`); `@CurrentUser()` reads the user. **Never gate a multipart upload with a guard** — guards run before the parser and the client sees ECONNRESET instead of your 403; check in the handler.
- **`src/middleware/globalMiddleware.ts`** is the only Express middleware left (helmet/CSP, CORS, HSTS, forced-HTTPS, logging, cookies).

## Tests

`tests/` is split into `unit/` (mirrors `src/`), `integration/`, `e2e/` (one `<domain>.e2e.test.ts` per module, booting the real guards against a temp DB via `tests/e2e/harness.ts`) and `websocket/`; helpers in `tests/helpers/`, fixtures in `tests/fixtures/`.

- **Upgrade fixtures**: `tests/fixtures/legacy/legacy-v*.sql` are databases the retired positional runner built; `tests/integration/legacy-upgrade-v*.test.ts` boot `buildApp()` on each. `legacy-v244` is the v4.3.3 release with rows across the main tables, rebuilt reproducibly by `node scripts/build-legacy-fixture-v244.mjs` (archives the tag into a temp dir, boots that release's runner, seeds, pins timestamps, dumps).

- **vitest uses the SWC plugin**, not esbuild, because Nest's DI needs emitted decorator metadata. Keep that in `vitest.config.ts`. Pool is `forks` (isolated DB per worker). The config also aliases `@modelcontextprotocol/sdk/*` to its CJS dist because the SDK's exports map is unresolvable.
- **Coverage is a per-domain ratchet over `src/nest/**`** (≥80% floor, most domains pinned higher). Regenerate the block with `scripts/coverage-thresholds.mjs` when coverage rises; never lower a threshold to land a change. Every folder under `src/nest/` needs its own entry (a new domain too): `tests/unit/coverage-thresholds.test.ts` fails on one that falls through to the pooled `src/nest/**` catch-all.
- CI also runs SonarCloud on the PR's new lines — see the root `CLAUDE.md`.

## Parity discipline (when adding or changing routes)

Routes are **byte-identical** for the client: same URL, method, query/body, status, `Set-Cookie` and JSON body, including bespoke error strings reproduced in the controller. Nest defaults POST to **201** — add `@HttpCode(200)` where the contract returns 200. Declare static sub-routes (`/reorder`, `/in-app/all`) **before** `:id` param routes. Trip-scoped handlers verify trip access (404) and permission (403).