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Queues
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Queues
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    1. Products
    2. Queues
    3. Examples
    4. Publish to a Queue via HTTP

    Publish to a Queue via HTTP

    Publish to a Queue directly via HTTP and Workers.

    The following example shows you how to publsh messages to a queue from any HTTP client, using a shared secret to securely authenticate the client.

    This allows you to write to a Queue from any service or programming language that support HTTP, including Go, Rust, Python or even a Bash script.

    ​​ Prerequisites

    Configure your wrangler.toml file as follows:

    wrangler.toml
    name = "my-worker"

    

    [[queues.producers]]
      queue = "my-queue"
      binding = "YOUR_QUEUE"

    ​​ 1. Create a shared secret

    Before you deploy the Worker, you need to create a secret that you can use as a shared secret. A shared secret is a secret that both the client uses to authenticate and the server (your Worker) matches against for authentication.

    To generate a cryptographically secure secret, you can use the openssl command-line tool and wrangler secret to create a hex-encoded string that can be used as the shared secret:

    $ openssl rand -hex 32

    # This will output a 65 character long hex string

    Copy this string and paste it into the prompt for wrangler secret:

    $ npx wrangler secret put QUEUE_AUTH_SECRET

    

    # Outputs:
    ✨ Success! Uploaded secret QUEUE_AUTH_SECRET

    This secret will also need to be used by the client application writing to the queue: ensure you store it securely.

    ​​ 2. Create the Worker

    The following Worker script:

    1. Authenticates the client using a shared secret.
    2. Validates that the payload uses JSON.
    3. Publishes the payload to the queue.
    src/index.ts
    interface Env {
    	YOUR_QUEUE: Queue;
    	QUEUE_AUTH_SECRET: string;

    }

    

    export default {
    	async fetch(req, env): Promise<Response> {
    		// Authenticate that the client has the correct auth key
    		if (env.QUEUE_AUTH_SECRET == "") {
    			return Response.json({ err: "application not configured" }, { status: 500 });
    		}
    

    		// Return a HTTP 403 (Forbidden) if the auth key is invalid/incorrect/misconfigured
    		let authToken = req.headers.get("Authorization") || "";
    		let encoder = new TextEncoder();
    		// Securely compare our secret with the auth token provided by the client
    		try {
    			if (!crypto.subtle.timingSafeEqual(encoder.encode(env.QUEUE_AUTH_SECRET), encoder.encode(authToken))) {
    				return Response.json({ err: "invalid auth token provided" }, { status: 403 });
    			}
    		} catch (e) {
    			return Response.json({ err: "invalid auth token provided" }, { status: 403 });
    		}
    

    		// Optional: Validate the payload is JSON
    		// In a production application, we may more robustly validate the payload
    		// against a schema using a library like 'zod'
    		let messages;
    		try {
    			messages = await req.json();
    		} catch (e) {
    			// Return a HTTP 400 (Bad Request) if the payload isn't JSON
    			return Response.json({ err: "payload not valid JSON" }, { status: 500 });
    		}
    

    		// Publish to the Queue
    		try {
    			await env.YOUR_QUEUE.send(messages);
    		} catch (e: any) {
    			console.log(`failed to send to the queue: ${e}`);
    			// Return a HTTP 500 (Internal Error) if our publish operation fails
    			return Response.json({ error: e.message }, { status: 500 });
    		}
    

    		// Return a HTTP 200 if the send succeeded!
    		return Response.json({ success: true });
    	},

    } satisfies ExportedHandler<Env>;

    To deploy this Worker:

    $ npx wrangler deploy

    ​​ 3. Send a test message

    To make sure you successfully authenticate and write a message to your queue, use curl on the command line:

    # Make sure to replace the placeholder with your shared secret

    $ curl -H "Authorization: pasteyourkeyhere" "https://YOUR_WORKER.YOUR_ACCOUNT.workers.dev" --data '{"messages": [{"msg":"hello world"}]}'

    # Outputs:
    {"success":true}

    This will issue a HTTP POST request, and if successful, return a HTTP 200 with a success: true response body.

    • If you receive a HTTP 403, this is because the Authorization header is invalid, or you did not configure a secret.
    • If you receive a HTTP 500, this is either because you did not correctly create a shared secret to your Worker, or you attempted to send an invalid message to your queue.

    You can use wrangler tail to debug the output of console.log.