𝕏tRPC

A CLI tool that helps you cleanly e𝕏port your tRPC router to

• 🔥🚀 massively boost your language server performance
• 💻😊 give your users a typed SDK so they can consume your API without hassle
• 🫗❌ ensure you don't leak any implementation details via ctx
• ✂️🌳 prune your router to expose only the routes you (or your users) care about

𝕏tRPC leverages the awesome ts-morph API to load, transform & emit the Typescript AST containing your tRPC definitions. Basically, it

1. (in-memory) redefines your Context type as any
2. (in-memory) "unimplements" your middlewares by transforming them into ({ ctx, next }) => next({ ctx })
3. (in-memory) prunes your router based on your needs
4. emits a minimal .d.ts file that declares your API

With the help of a type assertion, your app stays fully typesafe while you enjoy the performance benefits in your editor!

Demo

Performance

Compare how long it takes to write the same tRPC query with the help of Intellisense before and after compiling your API with 𝕏tRPC:

| Before (45s) | After (10s) | |---|---| | | |

Typed SDK

See algora-io/sdk as an example of how we published our own API

Table of Contents

• 𝕏tRPC
• Demo
  • Performance
  • Typed SDK
• Table of Contents
• Quickstart
  • Setup
    • Install the package
    • Generate your API
    • Include your types in tsconfig.json
    • Export your API & inference helpers
    • (Recommended) Add a type assertion to maintain type safety
    • Use API instead of AppRouter in your tRPC client
  • Usage
• Configuration
• Caveats

Quickstart

Setup

Install the package

Navigate to the project containing your tRPC router and run

pnpm add -D @algora/xtrpc

Generate your API

pnpm xtrpc

Include your types in tsconfig.json

{
  "include": ["index.ts", "src", "types"]
}

Export your API & inference helpers

export { type API } from "./types/api";
export type RouterInputs = inferRouterInputs<API>;
export type RouterOutputs = inferRouterOutputs<API>;

(Recommended) Add a type assertion to maintain type safety

type Expect<T extends true> = T;
type _Assertion = Expect<AppRouter extends API ? true : false>;

Use API instead of AppRouter in your tRPC client

export const trpc = createTRPCNext<API>({...})

Usage

Once you've set up your client to use the API, just rerun the tool to regenerate it whenever your type assertion fails

pnpm xtrpc

Configuration

Add a xtrpc.config.json file in your project to configure 𝕏tRPC. Below is the default configuration.

{
  // path to the project that contains your tRPC definitions
  "srcProject": ".",

  // path to the project that your API will be exported to
  "dstProject": ".",
  
  // name of the directory your API will be exported to
  "outDir": "types",
  
  // name of the file your API will be exported to
  "outName": "api.d.ts",
  
  // whether your API should be overwritten if it already exists
  "overwrite": false,
  
  // an optional Record<string, string[]> if you'd like to prune your router before exporting
  // keys are subrouters (i.e. the exported name of your subrouter)
  // values are procedures (i.e. the keys of your subrouter)
  "include": {}

  "parserOptions": {
    // type alias of your app router
    "appRouterAlias": "AppRouter"
  }
}

Caveats

• 𝕏tRPC may not work properly if your procedure outputs are not explicitly declared. For best results, add .output to all of your procedures (which is a good practice to not leak sensitive info anyways) and enable explicitOutputs in your xtrpc.config.json
• "Go to definition" jumps to the emitted .d.ts file instead of your source code. This can potentially be fixed by emitting declaration map(s) alongside your API.