# Vercel now supports Build Commands for FastAPI and Flask

By Steven Van · 2025-11-17

FastAPI and Flask projects on Vercel can now run a custom build step via a pyproject.toml script or the dashboard.

FastAPI and Flask apps on [Vercel](<https://creatorstoolbox.com/tools/vercel>) can now use a custom Build Command. It can be set in the project's Settings dashboard, or defined as a script under **\[tool.vercel.scripts\]** in pyproject.toml, for example build = "python build.py". The script runs after dependencies are installed but before the application deploys. A Build Command set in vercel.json or the Settings dashboard takes precedence over one defined in pyproject.toml. See the [full documentation](<https://vercel.com/docs/frameworks/backend/fastapi#build-command>) for details.

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

[Read Vercel now supports Build Commands for FastAPI and Flask on Creators Toolbox](<https://creatorstoolbox.com/blog/vercel-vercel-now-supports-build-commands-for-fastapi-and-flask>)

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Canonical source: https://creatorstoolbox.com/blog/vercel-vercel-now-supports-build-commands-for-fastapi-and-flask