Routing

For the most part, Connect handles HTTP routes for you — everything should just work. For debugging or more advanced configuration, this guide explains how Connect builds routes.

Constructing routes

Routing follows the Connect and gRPC HTTP/2 protocols, both of which use:

:method post
:path /<Package>.<Service>/<Method>

For example, method Greet of GreetService in Protobuf package greet.v1 has path /greet.v1.GreetService/Greet. Package, service, and method names are case-sensitive and used exactly as they are in the Protobuf schema, and handlers only support the GET and POST verbs. (Remember that routing is based on Protobuf package names, not Rust module paths.)

A Router holds the routes for any number of services. Each call to add_service registers every method of a generated service:

let router = Router::new()
    .add_service(Arc::new(GreetServer))
    .add_service(Arc::new(BillingServer));

Prefixing routes

Especially if you’re serving your Connect API alongside other HTTP handlers, you may want to prefix your RPC routes with /api/, /connect/, or something similar. You can do this by mounting your router in axum, which requires enabling the axum feature of connectrpc:

use connectrpc::Router;

let api = Router::new().add_service(Arc::new(GreetServer));

let app = axum::Router::new()
    .merge(new_html_router())
    .nest_service("/api", api.into_axum_service());

Most Tower-compatible routers work similarly. If you configure a prefix, be sure to include it in the base URL you pass to your Connect clients (for example, https://acme.com/api/). Unfortunately, many gRPC clients, such as grpc-go, don’t support prefixes: if you need to support gRPC clients, don’t prefix your routes!