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fastapi_tools.utils.url

URL utility functions for reverse-proxy-aware request handling.

Functions:

get_public_base_url 

get_public_base_url(
    request: Request, override: str | None = None
) -> str

Determine the public base URL of the application.

Resolution order: 1. override - explicit value (e.g. PUBLIC_BASE_URL env var). 2. X-Forwarded-Proto + X-Forwarded-Host headers (set by the proxy). 3. Scheme and netloc from the raw request URL (local / direct access).

Source code in src/fastapi_tools/utils/url.py 
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def get_public_base_url(request: Request, override: str | None = None) -> str:
    """Determine the public base URL of the application.

    Resolution order:
    1. override - explicit value (e.g. PUBLIC_BASE_URL env var).
    2. X-Forwarded-Proto + X-Forwarded-Host headers (set by the proxy).
    3. Scheme and netloc from the raw request URL (local / direct access).
    """
    if override:
        return override.rstrip("/")
    forwarded_proto = request.headers.get("x-forwarded-proto")
    forwarded_host = request.headers.get("x-forwarded-host")
    if forwarded_proto and forwarded_host:
        return f"{forwarded_proto}://{forwarded_host}"
    return f"{request.url.scheme}://{request.url.netloc}"