Reverse proxy and sub-apps¶

Behind a reverse proxy¶

Behind a proxy that serves the app under a path prefix, set the prefix on the server, for example with fastapi run --root-path /api/v1. The schema at /api/v1/openapi.json lists /api/v1 in servers, and keeps the validation error at the target code.

One override per app¶

override_validation_error applies to one FastAPI app. To use it on part of an API only, mount that part as its own app:

v2 = FastAPI()


@v2.post("/items")
def create_item_v2(item: Item) -> Item:
    return item


override_validation_error(v2)

app = FastAPI()


@app.post("/items")
def create_item(item: Item) -> Item:
    return item


app.mount("/v2", v2)

Each app keeps its own docs: /v2/docs for the mounted one, /docs for the other.