nextjs-fastapi-chat-app-starter
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Pull mirror status: ok
R
stubs and oidc
.agents
backend
frontend
.gitignore
README.md
skills-lock.json
vercel.json

Chat App Template

  • frontend/: Next.js app mounted at /
  • backend/: FastAPI app mounted at /api

Project Structure

.
├── backend/
│   ├── main.py
│   ├── storage.py
│   └── pyproject.toml
├── frontend/
│   ├── app/
│   │   ├── globals.css
│   │   ├── layout.js
│   │   └── page.js
│   └── package.json
└── vercel.json

Local Development

Run the services together:

cd ..
vercel dev -L

Local development stores chat history in SQLite at backend/.data/chat-history.sqlite3 by default. Override the path with SQLITE_PATH if needed.

Production Storage

In Vercel preview and production (VERCEL_ENV=preview or production), chat history uses Aurora PostgreSQL with IAM authentication via Vercel OIDC. Configure these environment variables:

  • PGHOST: Aurora cluster endpoint
  • PGUSER: database user, defaults to postgres
  • PGDATABASE: database name, defaults to postgres
  • AWS_REGION: AWS region for STS and RDS
  • AWS_ROLE_ARN: role assumed with Vercel's OIDC token

Set STORE=aurora to force Aurora outside production, or STORE=sqlite to force SQLite. For an ephemeral demo store, set STORE=runtime_cache to use Vercel Runtime Cache instead. Runtime Cache is regional and evictable, so it is useful for demos but should not be treated as durable chat history.

AI Model

The backend uses the Python ai SDK with Vercel AI Gateway. It first uses AI_GATEWAY_API_KEY when present, then falls back to a Vercel OIDC token via the Vercel Python SDK. Set AI_SDK_DEFAULT_MODEL to override the default Gateway model. Without Gateway auth, the app keeps using the local stub reply so vercel dev works end to end.