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connectrpc/connect-es

Important

You are looking at the release candidate for version 2. For the current stable version, see the branch v1.

Connect for ECMAScript

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Connect is a family of libraries for building type-safe APIs with different languages and platforms. @connectrpc/connect brings them to TypeScript, the web browser, and to Node.js.

With Connect, you define your schema first:

service ElizaService {
  rpc Say(SayRequest) returns (SayResponse) {}
}

And with the magic of code generation, this schema produces servers and clients:

const answer = await eliza.say({ sentence: "I feel happy." });
console.log(answer);
// {sentence: 'When you feel happy, what do you do?'}

Unlike REST, the Remote Procedure Call are type-safe, but they are regular HTTP under the hood. You can see all requests in the network inspector, and you can curl them if you want:

curl \
    --header 'Content-Type: application/json' \
    --data '{"sentence": "I feel happy."}' \
    https://demo.connectrpc.com/connectrpc.eliza.v1.ElizaService/Say

Connect uses Protobuf-ES, the only fully-compliant Protobuf JavaScript library.

Connect implements RPC three protocols: The widely available gRPC and gRPC-web protocols, and Connect's own protocol, optimized for the web. This gives you unparalleled interoperability across many platforms and languages, with type-safety end-to-end.

Get started on the web

Follow our 10 minute tutorial where we use Vite and React to create a web interface for ELIZA.

React, Svelte, Vue, Next.js and Angular are supported (see examples), and we have an expansion pack for TanStack Query. We support all modern web browsers that implement the widely available fetch API and the Encoding API.

Get started on Node.js

Follow our 10 minute tutorial to spin up a service in Node.js, and call it from the web, and from a gRPC client in your terminal.

You can serve your Connect RPCs with vanilla Node.js, or use our server plugins for Fastify, Next.js, and Express. We support Node.js v18.14.1 and later with the builtin http and http2 modules.

Other platforms

Would you like to use Connect on other platforms like Bun, Deno, Vercel’s Edge Runtime, or Cloudflare Workers? We’d love to learn about your use cases and what you’d like to do with Connect. You can reach us either through the Buf Slack or by filing a GitHub issue and we’d be more than happy to chat!

Packages

The libraries and the generated code are compatible with ES2017 and TypeScript 4.9.5.

Ecosystem

Legal

Offered under the Apache 2 license.