# Zero-configuration FastAPI backends

By Steven Van · 2025-09-25

FastAPI backends deploy without vercel.json redirects and run on Fluid compute with Active CPU pricing by default.

[Vercel](<https://creatorstoolbox.com/tools/vercel>) now recognizes FastAPI applications without any configuration, removing the need for redirects in vercel.json or routing through an /api folder. It looks for a FastAPI instance named app in files such as app.py, main.py, or asgi.py, or at a custom entrypoint set via tool.vercel.entrypoint in pyproject.toml.

FastAPI backends run on Fluid compute with Active CPU pricing by default, so they scale up and down with traffic and are billed only for compute actually used.

![Vercel](<https://www.google.com/s2/favicons?domain=vercel.com&sz=128>)

Vercel

The platform for frontend developers — deploy, preview, and scale web apps and AI agents with zero config.

[View Vercel →](<https://creatorstoolbox.com/tools/vercel>)

[Original source](<https://vercel.com/docs/frameworks/backend/fastapi>)

[Read Zero-configuration FastAPI backends on Creators Toolbox](<https://creatorstoolbox.com/blog/vercel-zero-configuration-fastapi-backends>)

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Canonical source: https://creatorstoolbox.com/blog/vercel-zero-configuration-fastapi-backends