To prevent anyone from triggering your workflow endpoint, you can use two methods: Use QStash’s built-in request verification to allow only authorized clients to trigger your workflow. Set two environment variables in addition to your QStash API key:
.env
QSTASH_CURRENT_SIGNING_KEY=xxxxxxxxx
QSTASH_NEXT_SIGNING_KEY=xxxxxxxxx
And replace xxxxxxxxx with your actual keys. Find both of these keys in your QStash dashboard under the “Signing keys” tab:
This will require every request to your workflow endpoint to include a valid signature, including the initial request that triggers a workflow. In other words: all requests need to come either from QStash (which automatically populates the Upstash-Signature header) or from a client that manually populates the Upstash-Signature header with your signing secret. We suggest using QStash’s publish API to trigger your workflow:
Terminal
curl -XPOST \
    -H 'Authorization: Bearer <YOUR_QSTASH_TOKEN>' \
    -H "Content-type: application/json" \
    -d '{ "initialData": "hello world" }' \
    'https://qstash.upstash.io/v2/publish/https://<your-app-url>/api/workflow'
For edge cases that do not support environment variables as outlined above, you can explicitly pass your signing keys to the serve function: 
import { Receiver } from "@upstash/qstash";
import { serve } from "@upstash/workflow/nextjs";

export const { POST } = serve(
  async (context) => {
    // Your workflow steps...
  },
  {
    receiver: new Receiver({
      currentSigningKey: process.env.QSTASH_CURRENT_SIGNING_KEY,
      nextSigningKey: process.env.QSTASH_NEXT_SIGNING_KEY,
    }),
  }
);

​
Custom Authorization Method

You can use your own authorization mechanism with Upstash Workflow. We ensure that the initial headers and initial request body will be available on every call made to your workflow. 
import { serve } from "@upstash/workflow/nextjs";

export const { POST } = serve(
  async (context) => {
    const authHeader = context.headers.get("authorization");
    const bearerToken = authHeader?.split(" ")[1];

    if (!isValid(bearerToken)) {
      console.error("Authentication failed.");
      return;
    }

    // Your workflow steps..
  },
  {
    failureFunction: async () => {
      const authHeader = context.headers.get("authorization");
      const bearerToken = authHeader?.split(" ")[1];

      if (!isValid(bearerToken)) {
        // ...
      }
    },
  }
);