roots-rpc

This package implements a fully-typed yet dead-simple RPC library for Typescript without any codegen required. Supports calling functions with any JSON-encodeable parameters and return values.

Also supports streaming results with observable-subscription pattern. See the test file for usage examples.

npm install roots-rpc

Example

This example shows calling a function from a client on a server. The function SumDiff takes in parameters a and b and it returns their sum as sum and difference as diff.

N.b: This is 100% typechecked, so any mismatch between the server implementation and client call site would cause a build-time error.

types.ts

import * as t from 'io-ts';

const Input = t.type({a: t.number, b: t.number});
const Output = t.type({sum: t.number, diff: t.number});
export const TInput = t.TypeOf<typeof Input>;
export const TOutput = t.TypeOf<typeof TOutput>;

export function SumDiff() {
    return {i: Input, o: Output};
}

server.ts

import { RpcServer } from "roots-rpc";
import { SumDiff } from "./types";

const rpcServer = new RpcServer(new Transport());
rpcServer.register(SumDiff, async ({ a, b }) => ({ sum: a + b, diff: a - b }));

client.ts

import { RpcClient } from "roots-rpc";
import { SumDiff } from "./types";

async function main() {
  const rpcClient = new RpcClient(new Transport());
  const getSumDiff = rpcClient.connect(SumDiff);
  const result = await getSumDiff({ a: 3, b: 1 });
  // result = {sum: 4, diff: 2}
}

Build

yarn
yarn build

Naming

Roots because it's:

• used in my Seattle Trees website
• ending in -ts, evoking Typescript
• a simple base layer for programs to build upon

https://pelmers.com/typesafe-rpc-without-codegen/