501 Not Implemented

HTTP/1.1 501 Not Implemented
Content-Type: application/json

{
  "error": "Not Implemented",
  "message": "The TRACE method is not supported by this server."
}

app.all("*", (req, res, next) => {
  const supportedMethods = ["GET", "POST", "PUT", "DELETE"];
  if (!supportedMethods.includes(req.method)) {
    return res.status(501).json({
      error: "Not Implemented",
      message: `Method ${req.method} is not supported.`
    });
  }
  next();
});

from fastapi import FastAPI, Request, HTTPException

app = FastAPI()

@app.middleware("http")
async def check_method(request: Request, call_next):
    if request.method not in ["GET", "POST", "PUT", "DELETE"]:
        raise HTTPException(status_code=501, detail="Method not implemented.")
    return await call_next(request)

package main

import "net/http"

func handler(w http.ResponseWriter, r *http.Request) {
	if r.Method == "FOO" {
		http.Error(w, "Method FOO Not Implemented", http.StatusNotImplemented)
		return
	}
	w.WriteHeader(http.StatusOK)
}

func main() {
	http.HandleFunc("/", handler)
	http.ListenAndServe(":8080", nil)
}

public class NotImplementedMiddleware
{
    private readonly RequestDelegate _next;
    public NotImplementedMiddleware(RequestDelegate next) => _next = next;

    public async Task Invoke(HttpContext context)
    {
        var method = context.Request.Method;
        if (method == "TRACE" || method == "TRACK")
        {
            context.Response.StatusCode = 501;
            await context.Response.WriteAsync("Method not implemented.");
            return;
        }
        await _next(context);
    }
}

# Sending a custom unrecognized HTTP method
curl -i -X WEIRD_METHOD https://api.example.com/