Post JSON
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Post JSON

Send a POST request with JSON data. Use to share data with external servers.

Last updated Jul 6, 2026 If you want to get started quickly, click on the button below.

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

export default {
    async fetch(request) {
        /**
         * Example someHost is set up to take in a JSON request
         * Replace url with the host you wish to send requests to
         * @param {string} url the URL to send the request to
         * @param {BodyInit} body the JSON data to send in the request
         */
        const someHost = "https://examples.cloudflareworkers.com/demos";
        const url = someHost + "/requests/json";
        const body = {
            results: ["default data to send"],
            errors: null,
            msg: "I sent this to the fetch",
        };

        /**
         * gatherResponse awaits and returns a response body as a string.
         * Use await gatherResponse(..) in an async function to get the response body
         * @param {Response} response
         */
        async function gatherResponse(response) {
            const { headers } = response;
            const contentType = headers.get("content-type") || "";
            if (contentType.includes("application/json")) {
                return JSON.stringify(await response.json());
            } else if (contentType.includes("application/text")) {
                return response.text();
            } else if (contentType.includes("text/html")) {
                return response.text();
            } else {
                return response.text();
            }
        }

        const init = {
            body: JSON.stringify(body),
            method: "POST",
            headers: {
                "content-type": "application/json;charset=UTF-8",
            },
        };
        const response = await fetch(url, init);
        const results = await gatherResponse(response);
        return new Response(results, init);
    },
};

export default {
    async fetch(request): Promise<Response> {
        /**
         * Example someHost is set up to take in a JSON request
         * Replace url with the host you wish to send requests to
         * @param {string} url the URL to send the request to
         * @param {BodyInit} body the JSON data to send in the request
         */
        const someHost = "https://examples.cloudflareworkers.com/demos";
        const url = someHost + "/requests/json";
        const body = {
            results: ["default data to send"],
            errors: null,
            msg: "I sent this to the fetch",
        };

        /**
         * gatherResponse awaits and returns a response body as a string.
         * Use await gatherResponse(..) in an async function to get the response body
         * @param {Response} response
         */
        async function gatherResponse(response) {
            const { headers } = response;
            const contentType = headers.get("content-type") || "";
            if (contentType.includes("application/json")) {
                return JSON.stringify(await response.json());
            } else if (contentType.includes("application/text")) {
                return response.text();
            } else if (contentType.includes("text/html")) {
                return response.text();
            } else {
                return response.text();
            }
        }

        const init = {
            body: JSON.stringify(body),
            method: "POST",
            headers: {
                "content-type": "application/json;charset=UTF-8",
            },
        };
        const response = await fetch(url, init);
        const results = await gatherResponse(response);
        return new Response(results, init);
    },
} satisfies ExportedHandler;

import json
from workers import WorkerEntrypoint, Response, fetch

async def gather_response(response):
    headers = response.headers
    content_type = headers["content-type"] or ""

    if "application/json" in content_type:
        return (content_type, json.dumps(dict(await response.json())))
    return (content_type, await response.text())

class Default(WorkerEntrypoint):
    async def fetch(self, _request):
        url = "https://jsonplaceholder.typicode.com/todos/1"

        body = {
            "results": ["default data to send"],
            "errors": None,
            "msg": "I sent this to the fetch",
        }

        response = await fetch(
            url,
            method="POST",
            body=json.dumps(body),
            headers={"content-type": "application/json;charset=UTF-8"},
        )
        content_type, result = await gather_response(response)

        return Response(result, headers={"content-type": content_type})

import { Hono } from 'hono';

const app = new Hono();

app.get('*', async (c) => {
  /**
   * Example someHost is set up to take in a JSON request
   * Replace url with the host you wish to send requests to
   */
  const someHost = "https://examples.cloudflareworkers.com/demos";
  const url = someHost + "/requests/json";
  const body = {
    results: ["default data to send"],
    errors: null,
    msg: "I sent this to the fetch",
  };

  /**
   * gatherResponse awaits and returns a response body as a string.
   * Use await gatherResponse(..) in an async function to get the response body
   */
  async function gatherResponse(response: Response) {
    const { headers } = response;
    const contentType = headers.get("content-type") || "";

    if (contentType.includes("application/json")) {
      return { contentType, result: JSON.stringify(await response.json()) };
    } else if (contentType.includes("application/text")) {
      return { contentType, result: await response.text() };
    } else if (contentType.includes("text/html")) {
      return { contentType, result: await response.text() };
    } else {
      return { contentType, result: await response.text() };
    }
  }

  const init = {
    body: JSON.stringify(body),
    method: "POST",
    headers: {
      "content-type": "application/json;charset=UTF-8",
    },
  };

  const response = await fetch(url, init);
  const { contentType, result } = await gatherResponse(response);

  return new Response(result, {
    headers: {
      "content-type": contentType,
    },
  });
});

export default app;

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description: Protect against timing attacks by safely comparing values using timingSafeEqual. title: Using timingSafeEqual image: https://developers.cloudflare.com/workers/examples/protect-against-timing-attacks/og.png?v=cc5591a626a4c5d0

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Post JSON

Post JSON

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