adapter-standalone
Mount tRPC on Node.js built-in HTTP server with createHTTPServer() from @trpc/server/adapters/standalone, createHTTPHandler() for custom http.createServer, createHTTP2Handler() for HTTP/2 with TLS. Configure basePath to slice URL prefix, CORS via the cors npm package passed as middleware option. CreateHTTPContextOptions provides req and res for context creation.
Source facts
- Repository
- trpc/trpc
- Last source activity
- March 28, 2026 at 10:58
- Detected SKILL.md language
- English
- Stars
- 40,667
- Forks
- 1,691
Install options
The review-first prompt is selected by default. You can switch to a direct command or download a local copy.
Review the source files
Read SKILL.md and any companion files shown by SkillsMP before deciding whether to install.
Showing SKILL.md
SKILL.md
Source instructions · Read-only preview- name
- adapter-standalone
- description
- Mount tRPC on Node.js built-in HTTP server with createHTTPServer() from @trpc/server/adapters/standalone, createHTTPHandler() for custom http.createServer, createHTTP2Handler() for HTTP/2 with TLS. Configure basePath to slice URL prefix, CORS via the cors npm package passed as middleware option. CreateHTTPContextOptions provides req and res for context creation.
- type
- core
- library
- trpc
- library_version
- 11.16.0
- requires
- ["server-setup"]
- sources
- ["www/docs/server/adapters/standalone.md","examples/standalone-server/src/server.ts"]
# tRPC — Adapter: Standalone
## Setup
```ts
// server.ts
import { initTRPC } from '@trpc/server';
import { createHTTPServer } from '@trpc/server/adapters/standalone';
import { z } from 'zod';
const t = initTRPC.create();
const appRouter = t.router({
greet: t.procedure
.input(z.object({ name: z.string() }))
.query(({ input }) => ({ greeting: `Hello, ${input.name}!` })),
});
export type AppRouter = typeof appRouter;
createHTTPServer({
router: appRouter,
createContext() {
return {};
},
}).listen(3000);
console.log('Listening on http://localhost:3000');
```
## Core Patterns
### CORS with the cors package
```ts
import { createHTTPServer } from '@trpc/server/adapters/standalone';
import cors from 'cors';
import { createContext } from './context';
import { appRouter } from './router';
createHTTPServer({
middleware: cors({ origin: 'http://localhost:5173' }),
router: appRouter,
createContext,
}).listen(3000);
```
Install CORS support: `npm install cors @types/cors`
### Custom HTTP server with createHTTPHandler
```ts
import { createServer } from 'http';
import { createHTTPHandler } from '@trpc/server/adapters/standalone';
import { appRouter } from './router';
const handler = createHTTPHandler({
router: appRouter,
createContext() {
return {};
},
});
createServer((req, res) => {
if (req.url?.startsWith('/health')) {
res.writeHead(200);
res.end('OK');
return;
}
handler(req, res);
}).listen(3000);
```
### basePath for URL prefix stripping
```ts
import { createServer } from 'http';
import { createHTTPHandler } from '@trpc/server/adapters/standalone';
import { appRouter } from './router';
const handler = createHTTPHandler({
router: appRouter,
basePath: '/trpc/',
});
createServer((req, res) => {
if (req.url?.startsWith('/trpc/')) {
return handler(req, res);
}
res.statusCode = 404;
res.end('Not Found');
}).listen(3000);
```
The `basePath` option strips the prefix before routing, so `/trpc/greet` resolves to the `greet` procedure.
### HTTP/2 with createHTTP2Handler
```ts
import http2 from 'http2';
import { readFileSync } from 'node:fs';
import { createHTTP2Handler } from '@trpc/server/adapters/standalone';
import type { CreateHTTP2ContextOptions } from '@trpc/server/adapters/standalone';
import { appRouter } from './router';
const tlsKey = readFileSync('./certs/server.key');
const tlsCert = readFileSync('./certs/server.crt');
async function createContext(opts: CreateHTTP2ContextOptions) {
return {};
}
const handler = createHTTP2Handler({
router: appRouter,
createContext,
});
const server = http2.createSecureServer(
{ key: tlsKey, cert: tlsCert },
(req, res) => {
handler(req, res);
},
);
server.listen(3001);
```
### Limiting batch size with maxBatchSize
```ts
import { createHTTPServer } from '@trpc/server/adapters/standalone';
import { appRouter } from './router';
createHTTPServer({
router: appRouter,
maxBatchSize: 10,
}).listen(3000);
```
Requests batching more than `maxBatchSize` operations are rejected with a `400 Bad Request` error. Set `maxItems` on your client's `httpBatchLink` to the same value to avoid exceeding the limit.
## Common Mistakes
### HIGH No CORS configuration for cross-origin requests
Wrong:
```ts
createHTTPServer({
router: appRouter,
createContext() {
return {};
},
}).listen(3000);
```
Correct:
```ts
import cors from 'cors';
createHTTPServer({
middleware: cors({ origin: 'http://localhost:5173' }),
router: appRouter,
createContext() {
return {};
},
}).listen(3000);
```
The standalone adapter has no CORS handling by default. Cross-origin browser requests fail silently because preflight OPTIONS requests receive no CORS headers.
Source: www/docs/server/adapters/standalone.md
## See Also
- **server-setup** -- `initTRPC.create()`, router/procedure definition, context
- **adapter-express** -- alternative adapter when you need Express middleware ecosystem
- **adapter-fetch** -- alternative adapter for edge/serverless runtimes
- **subscriptions** -- adding real-time subscriptions to a standalone server
View on GitHub