deckhearth/AGENTS.md

AGENTS.md — AI collaboration (tcg-vault)

Guidance for agents and humans working in this repo. Prefer existing patterns over new abstractions.

Branding note: the repo, README, and seed data say "TCG Vault" and admin@tcgvault.com, but the Layout component renders "Deck Hearth". Pick one before launch — see .convoys/ for tracking.

1. Project overview

A web app for managing trading-card-game collections (Magic, Pokémon, Lorcana). Users authenticate, build collections + decks, scan physical cards via a camera+AI-OCR flow, and share publicly. Admin users curate the card database.

• Framework: Next.js 16 (Pages router) + React 18, JavaScript (not TypeScript — see Gotcha #9)
• Data: Neon Postgres, accessed two different ways — @neondatabase/serverless (lib/database.js) AND raw @vercel/postgres (pages/api/**). Pick ONE; see Gotcha #1.
• Auth: Custom JWT (jsonwebtoken + bcryptjs), token stored in localStorage, sent as Authorization: Bearer …. No NextAuth. The secret + canonical 24h TTL come from lib/auth-secret.js (single source of truth; throws at module load if JWT_SECRET is unset). getUserFromRequest returns null for unauthenticated requests — no synthetic admin fallback — and login + register are rate-limited (5 attempts / 15 min via @upstash/ratelimit). The seed admin row (admin@tcgvault.com / admin123) still ships in scripts/setup-neon-db.js; see Gotcha #4.
• UI: Tailwind CSS + custom CSS variables for theming (light/dark via lib/theme-context.js)
• Hosting: Vercel (vercel.json, .vercel/ present)

2. Architecture quick reference

Area	Path	Notes
Pages router views	pages/*.js	Public + auth views; uses components/Layout.js
API routes	pages/api/**/*.js	Express-style handler(req, res). 30+ handlers depend on lib/permission-middleware.js::getUserFromRequest
Shared UI	components/*.js	Layout, CardItem, CameraScanner, modal family
Auth + DB libs	lib/*.js	auth-context, admin-auth, use-auth (three parallel auth surfaces), database, permission-middleware
Migration scripts	scripts/*.js	27+ one-off "add column" / "seed" scripts. No formal migration tool
Card-import jobs	pages/api/cards/import-*.js, scripts/import-*.js	Scryfall / Lorcana / Pokémon TCG APIs
Database schema	scripts/setup-neon-db.js	Bootstrap SQL DDL — the source of truth until a real migration tool lands
Schema map	docs/SCHEMA_MAP.md	Hand-curated; regenerate after schema changes

Code graph is indexed by user-code-review-graph MCP (122 files, 628 nodes, 5602 edges). Ask: "what calls getUserFromRequest?" before refactoring auth.

3. Key conventions

• Auth (server): import { getUserFromRequest } from '../../lib/permission-middleware' → returns { userId, email, role } or null. null means "send 401" — always early-return when the user is null before doing any work that depends on their identity.
• Auth (client): import { useAuth } from '../lib/use-auth'. Avoid lib/auth-context.js and lib/admin-auth.js for new code — they are legacy parallel implementations.
• JWT secret + TTL: import { JWT_SECRET, JWT_TOKEN_TTL } from '../../lib/auth-secret.js'. This is the only place either value is defined; do not reintroduce literal fallbacks. JWT_TOKEN_TTL = '24h' is canonical.
• Auth helper (token mint / verify / password hash): import { ... } from '../../pages/api/auth-utils' (generateToken, verifyToken, hashPassword, verifyPassword). Reads the secret + TTL from lib/auth-secret.js under the hood.
• Rate limiting: import { checkAuthRateLimit } from '../../lib/rate-limit.js' for any new auth-surface endpoint (/api/auth/login + /api/auth/register already wired). Returns { allowed, remaining, reset }; on !allowed return 429 with a Retry-After header. See .cursor/rules/api-routes.mdc § "Rate limiting" for the verbatim shape.
• Permission gate for collection routes: wrap handlers with withCollectionPermission('viewer' | 'editor' | 'owner') from lib/permission-middleware.js.
• DB access: Use tagged-template style — import { sql } from '@vercel/postgres'. Avoid the legacy lib/database.js db.query(string, params) API; its parameter interpolation uses sql.unsafe and is a SQL-injection vector.
• Activity logging: logCollectionActivity(collectionId, userId, action, details) — call it from any handler that mutates a collection.
• File names: kebab-case.js for libs/scripts; PascalCase.js for React components.
• Imports: No path aliases configured; use relative imports.
• Slugs: lib/slug-utils.js::generateUniqueSlug for any user-facing identifier (collections, decks).
• CSS theme tokens: Components read var(--bg-primary), var(--text-primary), var(--accent-ember), etc. — defined in styles/. Don't hardcode hex colors.

4. Common gotchas

• #1 — Two SQL clients live in parallel. @neondatabase/serverless (used by lib/database.js) and @vercel/postgres (used by most pages/api/** handlers). New code: prefer @vercel/postgres tagged templates. Migration to a single client is tracked in .convoys/.
• #2 — getUserFromRequest synthetic-admin fallback. RESOLVED by fix-auth-bypass Brief 2 (commit 258e479). The helper now returns null for unauthenticated requests; pages/api/auth/verify.js returns 401 on the no-token branch. The 16 unit tests in test/lib/permission-middleware.test.js lock in the contract, including a negative regression against the old synthetic-admin shape. Entry kept (not renumbered) to preserve the audit trail and stable cross-references.
• #3 — JWT_SECRET hardcoded across 7 files. RESOLVED by fix-auth-bypass Brief 1 (commit 4a10dce). lib/auth-secret.js is now the single source of truth and throws at module load when JWT_SECRET is unset. Canonical TTL is JWT_TOKEN_TTL = '24h'. The 'your-secret-key-change-in-production' literal is gone from all 7 sites; CI lint passes against the post-fix tree. Entry kept (not renumbered) to preserve cross-references.
• #4 — Default admin credentials are in the seed. admin@tcgvault.com / admin123 from scripts/setup-neon-db.js. Change the password immediately after running setup. Tracked by the queued drop-public-setup convoy.
• #5 — pages/api/setup-database.js public endpoint. RESOLVED by fix-auth-bypass Brief 3 (commit fc0dd73). The file is deleted along with the other three dev endpoints (/api/simple, /api/test-auth, /api/test-db), and .github/workflows/ci.yml's new forbidden-endpoints job fails the build if any of them are re-introduced (or if a new pages/api/test-*.js file appears). Entry kept (not renumbered) to preserve cross-references.
• #6 — Migrations are bare scripts. scripts/add-*.js and scripts/fix-*.js are run-once jobs with no idempotency tracking. Adopt node-pg-migrate, kysely, or drizzle-kit before more schema changes.
• #7 — Dual is_public semantics. Collections and decks both have is_public columns; check which controls discovery vs. anonymous read in the relevant route.
• #8 — Layout has hardcoded default user. Layout({ user = { email: 'me@randallstillwell.com', role: 'user' } }). Anything rendering Layout without passing user will impersonate the maintainer. Pass user explicitly from every page.
• #9 — typescript is a devDep, but the source is still JavaScript-only. package.json lists typescript@^5.9.3 purely so eslint-config-next@16's bundled typescript-eslint chain can satisfy its hard require('typescript') at module load (the peerDependenciesMeta.typescript.optional: true flag in eslint-config-next only suppresses npm's install-time warning, not the runtime require). There is no tsconfig.json, no .ts/.tsx files, and no // @ts-check directives. Do not rename .js files to .ts or add a tsconfig.json without an explicit convoy decision — TypeScript adoption is its own scope. See .convoys/bump-next-js.md § Decisions C.
• #10 — ESLint pinned to v9 (maintenance), not v10 (latest). devDependencies.eslint is ^9.39.4 even though latest is 10.4.0. We tried v10 and npm run lint crashed with TypeError: scopeManager.addGlobals is not a function because eslint-config-next@16's bundled typescript-eslint@8.x predates ESLint v10's redesigned global-ingestion path. Reverted to v9 under Decision D. Do NOT bump ESLint independently — wait for the queued bump-eslint-10 follow-up convoy, which is upstream-blocked until typescript-eslint ships a v10-tested release that eslint-config-next bundles. See .convoys/bump-next-js.md § Decisions D + "Follow-up convoys queued".
• #11 — Turbopack is now the default bundler. next dev and next build use Turbopack by default in Next.js 16. The fallback per command is --webpack (e.g. next build --webpack). We have no custom webpack: block in next.config.js, no custom loaders/aliases, and no Sass tilde imports, so Turbopack should "just work" — but if a build/runtime regression appears, reproduce on both bundlers before deciding whether to revert or pin a script to webpack. Do not pre-emptively switch to --webpack.
• #12 — Rate-limit env vars are KV_REST_API_URL / KV_REST_API_TOKEN, not UPSTASH_REDIS_REST_*. lib/rate-limit.js reads the Vercel Upstash Marketplace integration's auto-provisioned names. Three other Upstash-shaped vars exist in the Vercel-managed env (KV_URL, REDIS_URL, KV_REST_API_READ_ONLY_TOKEN) but our @upstash/redis REST client does not use them — do not wire to them. In prod, the rate-limit module fails closed if either of the two REST vars is missing (a single failed login is a better outcome than silently disabling brute-force protection). In dev / test, it warn-and-continues as a no-op so local work is unaffected when Upstash isn't wired up.

5. Running locally

• Runtime: Node 20 (Vercel default).
• Setup: npm install, copy .env.local template (POSTGRES_URL + JWT_SECRET + RESEND_API_KEY + BLOB_READ_WRITE_TOKEN; optionally KV_REST_API_URL + KV_REST_API_TOKEN to exercise the rate limiter locally — without them, lib/rate-limit.js warn-and-no-ops in dev), then npm run setup-db once.
• Dev server: npm run dev → http://localhost:3000.

6. Testing

• Unit-test runner: vitest@^3.2.4 (installed via fix-auth-bypass Brief 5, commit 1629afb). npm test for watch mode; npm run test:run for the CI / single-shot mode. Config in vitest.config.js, setup in test/setup.js (sets JWT_SECRET + NODE_ENV=test before any module loads). Specs live under test/ mirroring source layout (test/lib/*.test.js, test/api/*.test.js).
• Coverage today: 16 unit tests covering the post-fix-auth-bypass auth surface — lib/auth-secret.js (3), lib/permission-middleware.js::getUserFromRequest (8, incl. a negative regression against the old synthetic-admin shape — Gotcha #2), and pages/api/auth-utils.js (5). These tests lock in the contracts established by Briefs 1 and 2; do not weaken them when refactoring auth.
• CI: the test: job in .github/workflows/ci.yml runs npm run test:run on every PR and push to main and is blocking (no || true, no continue-on-error). A red test job blocks merge.
• E2E / smoke runner: @playwright/test is still pending — queued for the adopt-playwright-smoke convoy (see .convoys/ship-readiness.md § Proposed launch sequence step 10). Until it lands, preview-smoke.yml and visual-diff.yml are no-ops on the smoke side.
• Manual QA: TESTING_GUIDE.md still applies for surfaces not yet covered by automated tests (UI flows, scanner camera path, import jobs).

7. Deployment

• Vercel auto-deploys main and creates Preview deployments for every PR. vercel.json and .vercel/ are committed. CI in .github/workflows/ runs lint + types (no duplicate build — Vercel handles it).
• Preview protection bypass for automation. The project has a Protection Bypass for Automation token exposed locally as VERCEL_AUTOMATION_BYPASS_SECRET in .env.local (not committed). Smoke/visual-diff workflows pass this header (x-vercel-protection-bypass) when hitting password-protected preview URLs. Needed for the queued adopt-playwright-smoke convoy; do not log or echo the value.

8. Code graph

A local code-knowledge-graph MCP server (user-code-review-graph) is set up for this repo. Ask "what calls X?" or "show me the flow from /api/auth/login" instead of grepping. See docs/agent-context/README.md.