`wrangler types` for service bindings missing rpc methods

[nickfujita]

Which Cloudflare product(s) does this pertain to?

Wrangler

What versions & operating system are you using?

Wrangler 4.10.0, @cloudflare/vite-plugin 1.0.5

Please provide a link to a minimal reproduction

No response

Describe the Bug

When binding a service to call via RPC, the methods on the service worker are not available when running wrangler types. It just provides a generic typing Fetcher with the methods fetch and connect. I know @cloudflare/vite-plugin has the auxiliaryWorkers reference to the service worker wrangler.jsonc file, but guessing it's not at all related to how wrangler types works. Is there any way to provide a reference in my wrangler.jsonc to the service worker files so it can correctly pull in the types for the RPC methods on the service worker?

Service worker - worker-b

wrangler.jsonc

{
  "$schema": "node_modules/wrangler/config-schema.json",
  "name": "worker-b",
  "main": "src/index.ts",
  "compatibility_date": "2025-04-11",
}

src/index.tsx

import { WorkerEntrypoint } from 'cloudflare:workers';

export default class extends WorkerEntrypoint<Env> {

  async fetch() {
    return new Response('up');
  }

  async sayHello(greeting: string) {
    return `hello, ${greeting}`;
  }
}

Main worker - worker-a

wrangler.jsonc

{
  "$schema": "./node_modules/wrangler/config-schema.json",
  "name": "worker-a",
  "main": "src/index.ts",
  "compatibility_date": "2025-04-11",
  "services": [
    {
      "binding": "WORKER_B",
      "service": "worker-b"
    }
  ]
}

vite.config.ts

import { defineConfig } from "vite";
import { cloudflare } from "@cloudflare/vite-plugin";

export default defineConfig({
  plugins: [cloudflare({
    auxiliaryWorkers: [
      {
        configPath: '../worker-b/wrangler.jsonc'
      }
    ]
  })]
});

src/index.ts

export default {
  async fetch(request, env) {
    const result = await env.WORKER_B.sayHello('friend');
    return new Response(result);
  }
}

Expected

• in worker-a/src/index.ts, the typing for env.WORKER_B.sayHello should be available after running wrangler types

Actual

• the following type error is given

Property 'sayHello' does not exist on type '{ fetch(input: URL | RequestInfo, init?: RequestInit<CfProperties<unknown>> | undefined): Promise<Response>; connect(address: string | SocketAddress, options?: SocketOptions | undefined): Socket; }'.ts(2339)

• looking in the generated worker-configuration.d.ts file shows the following typings

declare namespace Cloudflare {
	interface Env {
		WORKER_B: Fetcher;
	}
}
type Fetcher<T extends Rpc.EntrypointBranded | undefined = undefined, Reserved extends string = never> = (T extends Rpc.EntrypointBranded ? Rpc.Provider<T, Reserved | "fetch" | "connect"> : unknown) & {
    fetch(input: RequestInfo | URL, init?: RequestInit): Promise<Response>;
    connect(address: SocketAddress | string, options?: SocketOptions): Socket;
};

Work around

• I could go in and update the WORKER_B type to extend Fetcher with the sayHello RPC method on WORKER_B but since this is a generated file, it just seems fragile. For example, what if a coworker regenerates the file by running wrangler types again and didn't know or forgets to add the extended type again.

Is there some other recommended way to handle this case?

Please provide any relevant error logs

No response

[emily-shen]

The current workaround we'd recommend is to create a new types file with overrides where needed, so you can freely regenerate your types but still manually type some parts.
And in that new file you'd have something like

interface Env extends BaseEnv {
	WORKER_B: Service<import("./worker-b").default>;
}

and that would mean env.WORKER_B has the correct rpc method types.

We're working on making this a smoother flow though 🧡

[mgandolfi7]

Hi @emily-shen I got this working for my IDE but when running tsc --noEmit in Worker A it now throws errors for Worker B. Is there anything we need to add/modify in our tsconfig?

[kotkoroid]

@mgandolfi7 I've faced the same issue. You need to provide a path to worker-configuration.d.ts of your worker B to your worker A.

[mgandolfi7]

@kotkoroid Thanks for the tip do you mind explaining further? I made sure to include worker B's worker-configuration.d.ts in my Worker A's tsconfig "include" like so:

	"include": [
		"worker-configuration.d.ts",
		"src/**/*.ts",
		"extended-env.d.ts",
		"../worker-b/worker-configuration.d.ts",
	]

but still same issue on my end.

[kotkoroid]

@mgandolfi7 I think the problem is that you are including it in include key which is telling the compiler which files to include in the compilation process. You need to put it into compilerOptions.types key.

[mgandolfi7]

@kotkoroid Thanks for the tip I’m still having trouble though. I should also point out that I don't have a root tsconfing and am using turborepo if that makes a difference.

[kotkoroid]

@mgandolfi7 I haven't tried using it with Turborepo. I suggest you open a new issue to address this or wait for solution mentioned by @emily-shen.

[kotkoroid]

@mgandolfi7 Hey, I just came across this and thought this might help you: https://www.npmjs.com/package/create-workers-monorepo

[emily-shen]

i'm not too sure about turborepo, but if you're able to produce a small repro i can have a look and see if i can find a solution.

however, once #8794 lands, you should be able to pass in the path to additional configs so that the generated types include the generics - that should then fix this issue 🎉

[nickfujita]

I'm also seeing the typecheck issue mentioned in #8902 (comment)

Created a minimal reproduction repo to confirm the issue: https://github.com/nickfujita/wrangler-types-services-issue

• Project is setup using the cf vite plugin for both worker-a and worker-b
• worker-b is a simple rpc worker that has an env var MY_VARIABLE
• worker-a binds worker-b as a service in it's wrangler.jsonc, and sets up the relative path reference to worker-b's wrangler.jsonc in it's vite.config.ts file under the cloudflare plugin option auxiliaryWorkers[0].configPath
• in worker-a you can confirm operation by running in worker-a folder npm i && npm run dev, accessing the server at http://localhost:5173/, and it should show the response myMethod: hello world
• in worker-a folder you can then run the command npm run typecheck to run tsc, this then produces the error in question below:

../worker-b/src/index.ts:9:32 - error TS2339: Property 'MY_VARIABLE' does not exist on type 'Env'.

9   return `myMethod: ${this.env.MY_VARIABLE} ${input}`
                                 ~~~~~~~~~~~


Found 1 error in ../worker-b/src/index.ts:9

I have also set in the tsconfig.json file in worker-a folder the types array with "../worker-b/worker-configuration.d.ts", referenced, but this does not appear to help.