Service Bindings

Service bindings let one worker call another without HTTP overhead.

Config

import { defineConfig, worker, workerEnv } from "wrangler-deploy";

const backend = worker("backend-worker");

export const api = workerEnv({
  BACKEND: backend,
});

export default defineConfig({
  version: 1,
  workers: ["apps/api", "apps/backend"],
  resources: {},
  serviceBindings: {
    "apps/api": {
      BACKEND: "apps/backend",
    },
  },
});

Worker code

import type { api } from "../../wrangler-deploy.config.ts";
type Env = typeof api.Env;
// Env.BACKEND is typed as Fetcher

export default {
  async fetch(req: Request, env: Env) {
    const res = await env.BACKEND.fetch(new Request("https://internal/data"));
    return res;
  },
};

Deploy order

wrangler-deploy infers deploy order from service bindings. The target worker deploys before the worker that depends on it. No manual deployOrder needed.

Stage suffixing

Service binding targets are automatically stage-suffixed. If apps/backend has worker name my-backend, the staging rendered config will reference my-backend-staging.