Python projects now support routing rules

Python projects can now use routing rules to set response headers or rewrite requests to internal paths, including apps built with FastAPI, Django, and Flask.

The Vercel CDN evaluates rules before requests reach your application, so changes apply without a new deployment.

For example, this FastAPI app serves a /new route:

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from fastapi import FastAPI
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app = FastAPI()
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@app.get("/new")
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def new_route() -> dict[str, str]:
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    return {"message": "New route!"}

To send requests for /old to that route, create a rewrite from the CDN tab in your project dashboard or with the Vercel CLI:

# Add a rewrite (staged automatically)
vercel routes add --ai "Rewrite /old to /new" --yes

# Review staged changes
vercel routes list --diff

# Publish to production
vercel routes publish

Published rules take effect immediately across all regions, and you can roll back to a previous version from the History tab.

You can also manage rules from Python with the vercel SDK, which wraps the Vercel REST API. add_route stages the rule, and update_route_version publishes it:

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from vercel.client import Vercel
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from vercel.project_routes import RewriteRoute
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vercel = Vercel(access_token="...")
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added = vercel.project_routes.add_route(
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    project_id="prj_123",
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    route=RewriteRoute(name="Rewrite /old to /new", source="/old", destination="/new"),
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)
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vercel.project_routes.update_route_version(
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    project_id="prj_123", version_id=added.version.id, action="promote"
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)

Rewrites can also be defined in vercel.json:

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{
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  "$schema": "https://openapi.vercel.sh/vercel.json",
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  "rewrites": [
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    {
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      "source": "/old",
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      "destination": "/new"
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    }
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  ]
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}

Project-level rules live outside your deployment and are evaluated before its routes, so a published rule takes precedence over a vercel.json rewrite for the same path. Each surface fits a different workflow:

Update Vercel CLI to the latest version and read the routing documentation to get started.