This guide gets you started with gRPC-Web with a simple working example from the browser.
### Prerequisites * `docker` and `docker-compose` This demo requires Docker Compose file [version 3](https://docs.docker.com/compose/compose-file/). Please refer to [Docker website](https://docs.docker.com/compose/install/#install-compose) on how to install Docker. ### Run an Echo example from the browser! ```sh $ git clone https://github.com/grpc/grpc-web $ cd grpc-web $ docker-compose pull $ docker-compose up -d node-server envoy commonjs-client ``` Open a browser tab, and go to: ```sh http://localhost:8081/echotest.html ``` To shutdown, run `docker-compose down`. ### What is Happening? In this demo, there are three key components: 1. `node-server`: This is a standard gRPC Server, implemented in Node. This server listens at port `:9090` and implements the service's business logic. 2. `envoy`: This is the Envoy proxy. It listens at `:8080` and forwards the browser's gRPC-Web requests to port `:9090`. This is done via a config file `envoy.yaml`. 3. `commonjs-client`: This component generates the client stub class using the `protoc-gen-grpc-web` protoc plugin, compiles all the JS dependencies using `webpack`, and hosts the static content `echotest.html` and `dist/main.js` using a simple web server at port `:8081`. Once the user interacts with the webpage, it sends a gRPC-Web request to the Envoy proxy endpoint at `:8080`. ### What's next - Work through a more detailed tutorial in [gRPC Basics: Web](/docs/tutorials/basic/web/)