Resell Backend

An open-sourced backend service for Resell.

Stack

• Runtime: Node 20, Express (routing-controllers + TypeORM 0.2)
• Database: Neon PostgreSQL 18 (pooled URL for the app, direct URL for migrations)
• Hosting: Vercel (Fluid Express). Docker Swarm / DigitalOcean are retired.

Semantic similarity (similar posts, request matching, search vectors) uses OpenAI embeddings (text-embedding-3-small) stored as float[], with exact cosine KNN in TypeScript. Set OPENAI_API_KEY in your .env. Without it, embeddings stay null and those features degrade gracefully. No pgvector extension is required.

Setup

1. Install Node 20 (nvm install 20 && nvm use 20).

2. From the repo root: npm install

3. Configure Neon for your editor (once per machine):

   npx neon@latest init

   Select Cursor, VS Code, and Claude CLI (Space to toggle). For Zed:

   npx add-mcp https://mcp.neon.tech/mcp -a zed -g

4. Link env vars to the Neon project (writes DATABASE_URL / DATABASE_URL_UNPOOLED into .env):

   npx neon@latest env pull

   Or copy .env_template to .env and fill values manually.

5. Firebase: set either FIREBASE_SERVICE_ACCOUNT_JSON (stringified JSON, preferred for Vercel) or FIREBASE_SERVICE_ACCOUNT_PATH (local file path).

6. Apply schema:

   npm run db:migrate

7. Run locally:

   npm run dev

   Health check: GET http://localhost:3000/health

Neon branches used by this project:

Neon branch	Use
production	Vercel Production
staging	Vercel Preview / main deploys
dev	Local development (optional personal branches later)

Project context is stored in .neon (safe to commit; no secrets).

Migrations

npm run db:migrate

CI runs migrations via .github/workflows/migrate-neon.yml using GitHub secrets:

• DATABASE_URL_UNPOOLED_PRODUCTION
• DATABASE_URL_UNPOOLED_STAGING
• DATABASE_URL_UNPOOLED_DEV

Push to release migrates production; push to main migrates staging. App deploy is handled by Vercel Git integration (not Docker).

Vercel

1. Import the GitHub repo in Vercel.
2. Set env vars for Production / Preview to match Neon branch URLs, plus Firebase JSON, OPENAI_API_KEY, upload settings, IS_PROD, and CRON_SECRET.
3. Entry is src/app.ts (default export for Fluid Express; app.listen only when not on Vercel).
4. Cron: vercel.json hits GET /api/cron/transaction-confirmations with Authorization: Bearer ${CRON_SECRET}. The transaction confirmation job body is still disabled until product re-enables it.

Seeding (optional)

npm run db:seed

Seeding is skipped when IS_PROD=true.

Deprecated

• Local Homebrew / Docker Postgres install (use Neon dev instead)
• DigitalOcean dump/import scripts (one-time migration only if needed)
• Dockerfile / docker-compose.yml and the disabled Swarm workflows under .github/workflows/deploy-*.yml