Deploy FastAPI to Vercel — uv, vercel CLI, production

How to deploy FastAPI on Vercel and set up the sample repo — handy if you’re new to Vercel or looking for a host for a small API. The free tier is generous for side projects.

What you’ll learn

• End-to-end FastAPI on Vercel
• uv for a local virtual environment
• Vercel CLI: vercel dev, vercel, vercel --prod
• Running pytest
• api/ layout and requirements.txt placement

Demo / template

Live sample:

You can also deploy from Vercel’s template:

You’ll need Git connected to Vercel.

Environment

• macOS Sequoia 15.5
• VS Code
• zsh 5.9 (arm64-apple-darwin24.0)

Prerequisites

• Python 3.12 (Vercel’s supported runtime as of mid-2025)
• uv (install)
• Vercel CLI (install)

Important for FastAPI on Vercel

Put serverless API code under api/, not the repo root — root placement didn’t work reliably for me.
requirements.txt must live at the project root or installs fail.

Local setup

1. Clone

git clone https://github.com/testkun08080/FastAPI-vercel.git
cd FastAPI-vercel

2. Virtual environment

uv venv -p 3.12
uv pip install -r requirements.txt

3. Run the app

uv run -m api.app.main

Open the local URL in a browser to verify.

Tests

1. Test dependencies

uv pip install -r requirements_test.txt

2. Pytest

uv run pytest --html=report.html --self-contained-html --log-level=INFO

Vercel CLI: dev → preview → production

Local dev (Vercel-like)

vercel dev

Preview deploy

vercel

Production deploy

vercel --prod

Summary

• FastAPI deploys cleanly on Vercel with uv + Vercel CLI from dev to prod.
• api/ for code, requirements.txt at repo root worked for me.
• Fast to ship for quick public APIs.