Simple, reliable, interoperable.

Protobuf RPC that works.

Connect is a family of libraries for building browser and gRPC-compatible APIs. If you're tired of hand-written boilerplate and turned off by massive frameworks, Connect is for you.

Use it with Curl

Supports any HTTP client

Plain HTTP

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

Use it with gRPCurl

Supports any gRPC client

gRPC protocol

$ grpcurl \
    -d '{"sentence": "I feel happy."}' \
    demo.connectrpc.com:443 \
    connectrpc.eliza.v1.ElizaService/Say
{"sentence": "Feeling happy? Tell me more."}Copy

Use it in web browsers

Supports React, Angular, Svelte, and other frameworks

Connect-Web

Production-grade simplicity

Connect shines in production. Implementations are focused — a few thousand lines of code, a handful of essential options, and a cURL-friendly protocol — which makes them stable, predictable, and debuggable.

Compatible with gRPC

In addition to its own protocol, Connect servers and backend clients also support gRPC — including streaming! They interoperate seamlessly with Envoy, grpcurl, gRPC Gateway, and every other gRPC implementation. Connect servers handle gRPC-Web requests natively, without a translating proxy.

Familiar primitives

Connect builds on primitives you already know. Go handlers slot right into your net/http server and work with your existing middleware, router, and observability. TypeScript clients stay close to the fetch API and integrate cleanly with popular UI frameworks.

No boilerplate

Define your APIs using Protocol Buffers, the industry's most battle-tested schema definition language, and skip the hand-written boilerplate. Connect handles server-side routing, serialization, and compression, and it generates idiomatic clients in Go, TypeScript, Swift, and Kotlin.

Learn more