@trpc/server

What is @trpc/server?

@trpc/server is a TypeScript-first framework for building end-to-end typesafe APIs. It allows you to create APIs where the client and server share the same type definitions, ensuring type safety across the entire stack.

What are @trpc/server's main functionalities?

Creating a Router

This code demonstrates how to create a basic router with a single procedure using @trpc/server. The `greeting` procedure returns a simple 'Hello, world!' message.

const { initTRPC } = require('@trpc/server');
const t = initTRPC.create();
const appRouter = t.router({
  greeting: t.procedure.query(() => 'Hello, world!'),
});
module.exports = { appRouter };

Creating Procedures

This code shows how to create a procedure that takes input and performs an operation. The `add` procedure takes two numbers as input and returns their sum.

const { initTRPC } = require('@trpc/server');
const t = initTRPC.create();
const appRouter = t.router({
  add: t.procedure.input((z) => z.object({ a: z.number(), b: z.number() })).query(({ input }) => input.a + input.b),
});
module.exports = { appRouter };

Middleware

This code demonstrates how to use middleware in @trpc/server. The `isAuthed` middleware checks if the user is authenticated before allowing access to the `secretData` procedure.

const { initTRPC } = require('@trpc/server');
const t = initTRPC.create();
const isAuthed = t.middleware(({ ctx, next }) => {
  if (!ctx.user) {
    throw new Error('Not authenticated');
  }
  return next();
});
const appRouter = t.router({
  secretData: t.procedure.use(isAuthed).query(() => 'Secret data'),
});
module.exports = { appRouter };

Other packages similar to @trpc/server

express

Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications. Unlike @trpc/server, Express does not provide built-in type safety and requires additional libraries for type checking and validation.

apollo-server

Apollo Server is a community-driven, open-source GraphQL server that works with any GraphQL schema. It provides a powerful way to build a GraphQL API with type safety, but it requires a different approach compared to @trpc/server, which is more focused on TypeScript and end-to-end type safety.

nestjs

NestJS is a progressive Node.js framework for building efficient, reliable, and scalable server-side applications. It uses TypeScript by default and provides a lot of built-in features, including dependency injection and a modular architecture. However, it is more heavyweight compared to @trpc/server.

README

tRPC

End-to-end typesafe APIs made easy

@trpc/server

Create tRPC routers and connect them to a server.

Documentation

Full documentation for @trpc/server can be found here

Installation

# npm
npm install @trpc/server

# Yarn
yarn add @trpc/server

# pnpm
pnpm add @trpc/server

# Bun
bun add @trpc/server

We also recommend installing zod to validate procedure inputs.

Basic Example

import { initTRPC } from '@trpc/server';
import {
  CreateHTTPContextOptions,
  createHTTPServer,
} from '@trpc/server/adapters/standalone';
import { z } from 'zod';

// Initialize a context for the server
function createContext(opts: CreateHTTPContextOptions) {
  return {};
}

// Get the context type
type Context = Awaited<ReturnType<typeof createContext>>;

// Initialize tRPC
const t = initTRPC.context<Context>().create();

// Create main router
const appRouter = t.router({
  // Greeting procedure
  greeting: t.procedure
    .input(
      z.object({
        name: z.string(),
      }),
    )
    .query(({ input }) => `Hello, ${input.name}!`),
});

// Export the app router type to be imported on the client side
export type AppRouter = typeof appRouter;

// Create HTTP server
const { listen } = createHTTPServer({
  router: appRouter,
  createContext,
});

// Listen on port 2022
listen(2022);