Connect

Connect is a family of libraries for building APIs that work in browsers and with gRPC clients. It uses Protocol Buffers and keeps the code close to standard HTTP and fetch patterns.

You define an API in Protocol Buffers, and Connect generates clients for languages such as Go, TypeScript, Swift, Kotlin, Dart, Python and Rust. Servers can answer plain HTTP requests, so a simple curl command can call them, and they also support gRPC and gRPC-Web. Go handlers fit into a normal net/http server and work with existing middleware. TypeScript clients stay close to the fetch API and work with common front-end frameworks. The protocol is designed to be easy to debug.

• Call APIs with curl or plain HTTP requests
• Generate clients in Go, TypeScript, Swift and more
• Serve gRPC-Web requests without a translating proxy
• Use Protocol Buffers to define APIs
• Work with React, Angular and Svelte in browsers

Backend teams that want gRPC compatibility without the overhead of a large framework will find it useful. Frontend developers who call Protocol Buffers APIs from the browser can also use the generated clients.

The project is open source under the Apache 2.0 license, so there is no license fee. It is best suited to teams that are comfortable with Protocol Buffers. Because the library is small, you may need to add other pieces, such as a logging or tracing setup, for a full production system.