Connect-Web

Connect-Web is a simple library to call remote procedures from a web browser. Unlike REST, you get a type-safe client and never have to think about serialization again.

The procedures are defined in a Protocol Buffer schema implemented by your backend, and Connect-Web generates the clients and related types to access the backend. The clients support two protocols: gRPC-web, and Connect's own protocol.

The Connect protocol is a simple, POST-only protocol that works over HTTP/1.1 or HTTP/2. It supports server-streaming methods just like gRPC-Web, but is easy to debug in the network inspector. Calling a Connect API is easy enough just with the fetch API. Try it with our live demo:

const res = await fetch("https://demo.connect.build/buf.connect.demo.eliza.v1.ElizaService/Say", {
  method: "POST",
  headers: {"content-type": "application/json"},
  body: `{"sentence": "I feel happy."}`
});
const answer = res.json();
console.log(answer);
// {sentence: 'When you feel happy, what do you do?'}

Using the client generated by Connect-Web, the same call becomes quite a bit simpler:

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

To get started, head over to the docs for a tutorial, or take a look at our examples for integration with various frameworks.

Supported Browsers

Connect-Web supports all modern web browsers that implement the widely available fetch API and the Encoding API. The library and the generated code are compatible with ES2017 and TypeScript 4.1.

Node.js is not supported. We are working on Connect for Node.js - if you are interested, let us know on Slack or on GitHub discussions.

Packages

@bufbuild/connect-web: Implements the Connect and gRPC-web protocols (source code).
@bufbuild/protoc-gen-connect-web: Code generator plugin for the services in your schema (source code).

Ecosystem

connect-web-integration: Example projects using Connect-Web with various JS frameworks and tooling
connect-go: Go implementation of gRPC, gRPC-Web, and Connect
connect-demo: demonstration service powering demo.connect.build
Buf Studio: web UI for ad-hoc RPCs
connect-crosstest: gRPC-Web and Connect interoperability tests

Status

This project is a beta: we rely on it in production, but we may make a few changes as we gather feedback from early adopters. We're planning to release a stable v1 later this year.

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