How to call a Worker from another Worker (403)

Inside of a Worker - how do you call another Worker without Cloudflare challenging the request? E.g.

//Worker A
export default {
  async fetch(request, env) {
    //Worker B
    await fetch('https://test.workers.dev');
    //^ This throws 403 with a CF challenge
  }
}

//Worker A
export default {
  async fetch(request, env) {
    //Worker B
    await fetch('https://test.workers.dev');
    //^ This throws 403 with a CF challenge
  }
}

I've tried adding a bunch of headers into the Fetch - but still get the 403. Is there a way to tell Cloudflare to trust its own IPs?

4 Replies

AstroDevOP•6mo ago

Do you mean RPC?

Chaika•6mo ago

it doesn't have to be, can just be the fetch handler: https://developers.cloudflare.com/workers/runtime-apis/bindings/service-bindings/

Cloudflare Docs

Service bindings - Runtime APIs · Cloudflare Workers docs

Facilitate Worker-to-Worker communication.

Chaika•6mo ago

Service Bindings are a smart idea to use anyway if you have control over both workers as they run in same isolate/no network If two workers execute on the same zone (ex: workers.dev is a zone, anything under websites is a zone), they'll never be able to call each other, cookies.me.workers.dev -> cookies2.me.workers.dev = no worker1.cookies.dev -> worker2.cookies.dev = no worker1.cookies.dev-> cookies2.me.workers.dev = yes

AstroDevOP•6mo ago

Thanks!

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How to call a Worker from another Worker (403)