TypeScript Client

This guide shows how to use the ts-client target (vanilla TypeScript client).

Prerequisites

1. Define your API contract (see API Contract) and export router
2. Generate client code: xrpc generate --targets ts-client
3. Use the generated client in your application

Note: The xRPC CLI runs on Node.js (>= 18). The generated client runs on Node.js or Bun (fetch API). Runtime validation uses zod, so make sure zod is installed. The generated types import router from your contract file and use xrpckit type utilities, so keep xrpckit in your dev dependencies for type-checking.

Server generation for Express is planned as a separate ts-express target.

Generated Code Structure

Generated files are written to <output>/xrpc/:

• client.ts: Type-safe client implementation using fetch API
• types.ts: Zod schema exports and inferred input/output types

Basic Usage

import { createClient } from './xrpc/client';  // Generated code

const api = createClient({
  baseUrl: 'http://localhost:3000/api',
  validateInputs: true,
  validateOutputs: true,
});

// Call a query
const result = await api.greeting.greet({ name: 'World' });
console.log(result.message); // "Hello, World!"

// Call a mutation
const greeting = await api.greeting.setGreeting({
  name: 'Alice',
  greeting: 'Hi',
});
console.log(greeting.message); // "Hi, Alice!"

Type Safety

All API calls are fully type-safe with autocomplete:

// TypeScript knows the input type
const result = await api.greeting.greet({
  name: 'World',  // ✅ Type-checked
});

// TypeScript knows the output type
console.log(result.message); // ✅ Type-checked

Error Handling

try {
  const result = await api.greeting.greet({ name: 'World' });
  console.log(result.message);
} catch (error) {
  console.error('API call failed:', error);
}