_extract_endpoint_context() — fastapi Function Reference

Architecture documentation for the _extract_endpoint_context() function in routing.py from the fastapi codebase.

Function python FastAPI Routing called by 2

Entity Profile

FastAPI→ Routing→ _extract_endpoint_context() — fastapi Function Reference

Dependency Diagram

graph TD
  74570640_d48f_6978_d994_fcf56400f5f3["_extract_endpoint_context()"]
  de395a51_26f8_3424_1af0_2f5bef39c893["routing.py"]
  74570640_d48f_6978_d994_fcf56400f5f3 -->|defined in| de395a51_26f8_3424_1af0_2f5bef39c893
  ad8d62d9_53da_514b_c06f_53293eb1e5ae["get_request_handler()"]
  ad8d62d9_53da_514b_c06f_53293eb1e5ae -->|calls| 74570640_d48f_6978_d994_fcf56400f5f3
  a0d87950_5de5_3ab2_72f7_0a20a6e00434["get_websocket_app()"]
  a0d87950_5de5_3ab2_72f7_0a20a6e00434 -->|calls| 74570640_d48f_6978_d994_fcf56400f5f3
  style 74570640_d48f_6978_d994_fcf56400f5f3 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

fastapi/routing.py lines 241–261

def _extract_endpoint_context(func: Any) -> EndpointContext:
    """Extract endpoint context with caching to avoid repeated file I/O."""
    func_id = id(func)

    if func_id in _endpoint_context_cache:
        return _endpoint_context_cache[func_id]

    try:
        ctx: EndpointContext = {}

        if (source_file := inspect.getsourcefile(func)) is not None:
            ctx["file"] = source_file
        if (line_number := inspect.getsourcelines(func)[1]) is not None:
            ctx["line"] = line_number
        if (func_name := getattr(func, "__name__", None)) is not None:
            ctx["function"] = func_name
    except Exception:
        ctx = EndpointContext()

    _endpoint_context_cache[func_id] = ctx
    return ctx