grpc-web

A Rust gRPC server with built-in gRPC-Web support and a TypeScript browser client. This repo demonstrates an end-to-end setup where the browser calls a Rust backend over gRPC-Web without needing Envoy, thanks to tonic-web.

What's inside

• protos/grpc-web.proto — shared Protocol Buffers definitions
• rust/grpc-web-server/ — gRPC server in Rust using tonic + tonic-web
• web/grpc-web-client/ — Vite + TypeScript browser client using Connect

Services (from the proto):

• Echo — send a message and receive it back
• DoMath — add, subtract, multiply, or divide two numbers

Prerequisites

• Rust 1.70+
• Node.js 18+ and npm

No protoc or other system proto tools required — the client uses buf (installed via npm).

Quick start

1. Start the Rust server (listens on http://0.0.0.0:10000)

cd rust/grpc-web-server
cargo run

2. Start the web client (served on http://localhost:8080)

cd web/grpc-web-client
npm install
npm run dev

Open http://localhost:8080 and try Echo and Calculator.

Development workflow

• Edit shared proto definitions in protos/grpc-web.proto.
• The Rust server regenerates its types automatically via build.rs on cargo build.
• Regenerate the TypeScript client stubs with npm run proto-regen in web/grpc-web-client/.

Production build

Server:

cd rust/grpc-web-server
cargo build --release

Client:

cd web/grpc-web-client
npm run build

Serve the dist/ folder from any static file server or CDN, pointed at the deployed server URL.

Subproject docs

• Rust server: rust/grpc-web-server/README.md
• Web client: web/grpc-web-client/README.md

Troubleshooting

• CORS errors in the browser — verify the server is running on :10000 with CORS enabled for http://localhost:8080.
• Proto not found — confirm protos/grpc-web.proto exists and buf.gen.yaml paths are correct.

License

Licensed under the terms of the LICENSE file in the repository root.