tRPC Bun Adapter


Description

trpc-bun-adapter is a tRPC adapter for Bun.

Start both HTTP and WebSockets transports with ease.

Quick Start

Install packages:
``bash
bun install @trpc/server trpc-bun-adapter
`

Create a server.ts file with the following content:
`ts
import {initTRPC} from '@trpc/server';
import {createBunServeHandler} from 'trpc-bun-adapter';

const t = initTRPC.create();

export const router = t.router({
ping: t.procedure.query(() => "pong"),
});

Bun.serve(createBunServeHandler({ router }));
`

To start the server, run:
`bash
bun run server.ts
bun run --watch server.ts # to restart on file changes
`

Check that it works:
`bash
curl http://localhost:3000/ping
`

Example

for a full example, see the example directory.

API Reference

Ensure you have created a router.ts file as outlined in the tRPC documentation: Define Routers.

$3

Creates a Bun serve handler:

`ts
import {createBunServeHandler, CreateBunContextOptions} from 'trpc-bun-adapter';
import {router} from './router';

const createContext = (opts: CreateBunContextOptions) => ({
user: 1,
});

Bun.serve(
createBunServeHandler(
{
router,
// optional arguments:
endpoint: '/trpc', // Default to ""
createContext,
onError: console.error,
responseMeta(opts) {
return {
status: 202,
headers: {},
}
},
batching: {
enabled: true,
},
},
{
// Bun serve options
port: 3001,
fetch(request, server) {
// will be executed if it's not a TRPC request
return new Response("Hello world");
},
},
),
);
`

To add response headers like Cross-origin resource sharing (CORS) use responseMeta option:
`ts
Bun.serve(
createBunServeHandler({
router: appRouter,
responseMeta(opts) {
return {
status: 200,
headers: {
"Access-Control-Allow-Origin": "*",
"Access-Control-Allow-Methods": "GET, POST, OPTIONS",
"Access-Control-Allow-Headers": "Content-Type, Authorization"
}
};
}
}
)
);
`

$3

Creates a Bun HTTP handler for tRPC HTTP requests:

`ts
import {createBunHttpHandler, CreateBunContextOptions} from 'trpc-bun-adapter';
import {router} from './router';

const createContext = (opts: CreateBunContextOptions) => ({
user: 1,
});

const bunHandler = createBunHttpHandler({
router,
// optional arguments:
endpoint: '/trpc', // Default to ""
createContext,
onError: console.error,
responseMeta(opts) {
return {
status: 202,
headers: {},
}
},
batching: {
enabled: true,
},
emitWsUpgrades: false, // pass true to upgrade to WebSocket
});

Bun.serve({
fetch(request, response) {
return bunHandler(request, response) ?? new Response("Not found", {status: 404});
}
});
`

$3

Creates a Bun WebSocket handler for tRPC websocket requests:

`ts
import { createBunWSHandler, CreateBunContextOptions } from './src';
import { router } from './router';

const createContext = (opts: CreateBunContextOptions) => ({
user: 1,
});

const websocket = createBunWSHandler({
router,
// optional arguments:
createContext,
onError: console.error,
batching: {
enabled: true,
},
});

Bun.serve({
fetch(request, server) {
if (server.upgrade(request, {data: {req: request}})) {
return;
}

return new Response("Please use websocket protocol", {status: 404});
},
websocket,
});
`

$3

To ensure your router recognizes the context type, define a createContext function utilizing the CreateBunContextOptions type:

`ts
import { initTRPC } from '@trpc/server';
import type { CreateBunContextOptions } from "src/createBunHttpHandler";

export const createContext = async (opts: CreateBunContextOptions) => {
return {
authorization: req.headers.get('Authorization')
};
};
`

With createContext defined, you can use it in your router to access the context, such as the authorization information:
`ts
const t = initTRPC.context().create();

export const router = t.router({
session: t.procedure.query(({ ctx }) => ctx.authorization),
});
`

Finally, pass your createContext function besides router to createBunHttpHandler.
This integrates your custom context into the HTTP handler setup:
`ts
createBunHttpHandler({
router,
createContext,
})
``

Read more documentation about tRPC contexts here: Contexts

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Feel free to open issues and pull requests.