---
title: Modify request property
description: Create a modified request with edited properties based off of an incoming request.
image: https://edgetunnel-b2h.pages.dev/dev-products-preview.png
---

> Documentation Index  
> Fetch the complete documentation index at: https://edgetunnel-b2h.pages.dev/workers/llms.txt  
> Use this file to discover all available pages before exploring further. 

[Skip to content](#%5Ftop) 

# Modify request property

Create a modified request with edited properties based off of an incoming request.

If you want to get started quickly, click on the button below.

[![Deploy to Cloudflare](https://deploy.workers.cloudflare.com/button)](https://deploy.workers.cloudflare.com/?url=https://github.com/cloudflare/docs-examples/tree/main/workers/modify-request-property)

This creates a repository in your GitHub account and deploys the application to Cloudflare Workers.

* [  JavaScript ](#tab-panel-12560)
* [  TypeScript ](#tab-panel-12561)
* [  Python ](#tab-panel-12562)
* [  Hono ](#tab-panel-12563)

**JavaScript**

```js
export default {
  async fetch(request) {
    /**
     * Example someHost is set up to return raw JSON
     * @param {string} someUrl the URL to send the request to, since we are setting hostname too only path is applied
     * @param {string} someHost the host the request will resolve too
     */
    const someHost = "example.com";
    const someUrl = "https://foo.example.com/api.js";


    /**
     * The best practice is to only assign new RequestInit properties
     * on the request object using either a method or the constructor
     */
    const newRequestInit = {
      // Change method
      method: "POST",
      // Change body
      body: JSON.stringify({ bar: "foo" }),
      // Change the redirect mode.
      redirect: "follow",
      // Change headers, note this method will erase existing headers
      headers: {
        "Content-Type": "application/json",
      },
      // Change a Cloudflare feature on the outbound response
      cf: { apps: false },
    };


    // Change just the host
    const url = new URL(someUrl);


    url.hostname = someHost;


    // Best practice is to always use the original request to construct the new request
    // to clone all the attributes. Applying the URL also requires a constructor
    // since once a Request has been constructed, its URL is immutable.
    const newRequest = new Request(
      url.toString(),
      new Request(request, newRequestInit),
    );


    // Set headers using method
    newRequest.headers.set("X-Example", "bar");
    newRequest.headers.set("Content-Type", "application/json");
    try {
      return await fetch(newRequest);
    } catch (e) {
      return new Response(JSON.stringify({ error: e.message }), {
        status: 500,
      });
    }
  },
};
```

**TypeScript**

```ts
export default {
  async fetch(request): Promise<Response> {
    /**
     * Example someHost is set up to return raw JSON
     * @param {string} someUrl the URL to send the request to, since we are setting hostname too only path is applied
     * @param {string} someHost the host the request will resolve too
     */
    const someHost = "example.com";
    const someUrl = "https://foo.example.com/api.js";


    /**
     * The best practice is to only assign new RequestInit properties
     * on the request object using either a method or the constructor
     */
    const newRequestInit = {
      // Change method
      method: "POST",
      // Change body
      body: JSON.stringify({ bar: "foo" }),
      // Change the redirect mode.
      redirect: "follow",
      // Change headers, note this method will erase existing headers
      headers: {
        "Content-Type": "application/json",
      },
      // Change a Cloudflare feature on the outbound response
      cf: { apps: false },
    };


    // Change just the host
    const url = new URL(someUrl);


    url.hostname = someHost;


    // Best practice is to always use the original request to construct the new request
    // to clone all the attributes. Applying the URL also requires a constructor
    // since once a Request has been constructed, its URL is immutable.
    const newRequest = new Request(
      url.toString(),
      new Request(request, newRequestInit),
    );


    // Set headers using method
    newRequest.headers.set("X-Example", "bar");
    newRequest.headers.set("Content-Type", "application/json");
    try {
      return await fetch(newRequest);
    } catch (e) {
      return new Response(JSON.stringify({ error: e.message }), {
        status: 500,
      });
    }
  },
} satisfies ExportedHandler;
```

**Python**

```py
import json
from workers import WorkerEntrypoint, Response, fetch
from js import Request
from urllib.parse import urlparse


class Default(WorkerEntrypoint):
    async def fetch(self, request):
        some_host = "example.com"
        some_url = "https://foo.example.com/api.js"


        # The best practice is to only assign new_request_init properties
        # on the request object using either a method or the constructor
        new_request_init = {
            "method": "POST", # Change method
            "body": json.dumps({"bar": "foo"}), # Change body
            "redirect": "follow", # Change the redirect mode
            # Change headers, note this method will erase existing headers
            "headers": {
                "Content-Type": "application/json",
            },
            #  Change a Cloudflare feature on the outbound response
            "cf": {"apps": False},
        }


        # Change just the host
        parsed = urlparse(some_url)
        new_url = parsed._replace(netloc=some_host).geturl()


        # Best practice is to always use the original request to construct the new request
        # to clone all the attributes. Applying the URL also requires a constructor
        # since once a Request has been constructed, its URL is immutable.
        org_request = Request.new(request, new_request_init)
        new_request = Request.new(new_url, org_request)


        new_request.headers["X-Example"] = "bar"
        new_request.headers["Content-Type"] = "application/json"


        try:
            return await fetch(new_request)
        except Exception as e:
            return Response.join({"error": str(e)}, status=500)
```

**TypeScript**

```ts
import { Hono } from "hono";


const app = new Hono();


app.all("*", async (c) => {
  /**
   * Example someHost is set up to return raw JSON
   */
  const someHost = "example.com";
  const someUrl = "https://foo.example.com/api.js";


  // Create a URL object to modify the hostname
  const url = new URL(someUrl);
  url.hostname = someHost;


  // Create a new request
  // First create a clone of the original request with the new properties
  const requestClone = new Request(c.req.raw, {
    // Change method
    method: "POST",
    // Change body
    body: JSON.stringify({ bar: "foo" }),
    // Change the redirect mode
    redirect: "follow" as RequestRedirect,
    // Change headers, note this method will erase existing headers
    headers: {
      "Content-Type": "application/json",
      "X-Example": "bar",
    },
    // Change a Cloudflare feature on the outbound response
    cf: { apps: false },
  });


  // Then create a new request with the modified URL
  const newRequest = new Request(url.toString(), requestClone);


  // Send the modified request
  const response = await fetch(newRequest);


  // Return the response
  return response;
});


// Handle errors
app.onError((err, c) => {
  return err.getResponse();
});


export default app;
```

```json
{"@context":"https://schema.org","@type":"TechArticle","@id":"https://edgetunnel-b2h.pages.dev/workers/examples/modify-request-property/#page","headline":"Modify request property · Cloudflare Workers docs","description":"Create a modified request with edited properties based off of an incoming request.","url":"https://edgetunnel-b2h.pages.dev/workers/examples/modify-request-property/","inLanguage":"en","image":"https://edgetunnel-b2h.pages.dev/dev-products-preview.png","dateModified":"2026-07-06","publisher":{"@type":"Organization","name":"Cloudflare","url":"https://www.cloudflare.com/"},"isPartOf":{"@type":"WebSite","@id":"https://edgetunnel-b2h.pages.dev/#website","name":"Cloudflare Docs","url":"https://edgetunnel-b2h.pages.dev/"},"keywords":["Middleware","Headers","JavaScript","TypeScript","Python"]}
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/workers/","name":"Workers"}},{"@type":"ListItem","position":3,"item":{"@id":"/workers/examples/","name":"Examples"}},{"@type":"ListItem","position":4,"item":{"@id":"/workers/examples/modify-request-property/","name":"Modify request property"}}]}
```