grpc-web

Rust gRPC server with built‑in gRPC‑Web support and a TypeScript (Vite) browser client. This repo shows an end‑to‑end setup where the browser talks to 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 implemented in Rust using tonic + tonic‑web
• web/grpc-web-client/ – Vite + TypeScript client that calls the server via gRPC‑Web

Services provided (from the proto and server):

• Echo: send a message and receive it back
• Math: perform add/subtract/multiply/divide via a do_math RPC

Prerequisites

• Rust 1.70+
• Node.js 18+ and npm
• Protocol Buffer compiler (protoc)
• gRPC‑Web protoc plugin (protoc-gen-grpc-web)
  • macOS (Homebrew): brew install protobuf protoc-gen-grpc-web

Quick start

1. Start the Rust gRPC‑Web server (default listens on http://0.0.0.0:10000)

cd rust/grpc-web-server
cargo run

2. Install client deps and generate stubs (only needed if proto changed) and run the client (Vite on http://localhost:8080)

cd web/grpc-web-client
npm install
npm run proto-regen   # or npm run proto-gen if you don’t need a clean
npm run dev

Open http://localhost:8080 and try Echo and Calculator. The client calls the server at http://localhost:10000 using gRPC‑Web. CORS is enabled on the server for local development.

Development workflow

• Update shared messages/services in protos/grpc-web.proto.
• Rebuild the Rust server (build.rs will re‑generate Rust types via prost/tonic‑build).
• Re‑generate client code in web/grpc-web-client with npm run proto-regen.

Production

• Server: build a release binary

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

• Client: build static assets to dist/

cd web/grpc-web-client
npm run build

Serve the client’s dist/ behind your preferred static file server or CDN. Point it at the deployed server URL with gRPC‑Web enabled (and appropriate CORS/TLS in front if needed).

Docs for subprojects

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

Troubleshooting

• protoc or plugin not found: ensure protoc and protoc-gen-grpc-web are installed and on PATH.
• CORS errors in the browser: verify the server is running on :10000 and CORS is permissive for the dev origin http://localhost:8080.
• Proto not found: confirm protos/grpc-web.proto exists and paths in scripts match.

License

This project is licensed under the terms of the LICENSE file in the repository root.