CopilotKit/CopilotKit · error · HTTPException

{key} is required

Error message

{key} is required

What it means

Error "{key} is required" thrown in CopilotKit/CopilotKit.

Source

Thrown at sdk-python/copilotkit/integrations/fastapi.py:73

            future = loop.run_in_executor(executor, run_handler_in_thread, request, sdk)
            return await future
        return await handler(request, sdk)

    # Ensure the prefix starts with a slash and remove trailing slashes
    normalized_prefix = "/" + prefix.strip("/")

    fastapi_app.add_api_route(
        f"{normalized_prefix}/{{path:path}}",
        make_handler,
        methods=["GET", "POST", "PUT", "DELETE", "OPTIONS"],
    )


def body_get_or_raise(body: Any, key: str):
    """Get value from body or raise an error"""
    value = body.get(key)
    if value is None:
        raise HTTPException(status_code=400, detail=f"{key} is required")
    return value


async def handler(request: Request, sdk: CopilotKitRemoteEndpoint):
    """Handle FastAPI request"""

    try:
        body = await request.json()
    except:  # pylint: disable=bare-except
        body = None

    # Propagate x-aimock-* headers to outgoing LLM calls via ContextVar
    set_forwarded_headers(dict(request.headers))

    path = request.path_params.get("path")
    method = request.method
    context = cast(
        CopilotKitContext,

View on GitHub (pinned to 68fbe97d87)

When it happens

Trigger: Thrown at sdk-python/copilotkit/integrations/fastapi.py:73 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of CopilotKit/CopilotKit@68fbe97d87 (2026-08-27). Data as JSON: /api/errors/9385d2a7bdcf19d3. Report an issue: GitHub.