Customizable examples for extending the Cosmo Router with custom modules and middleware.

Router Documentation • Module Configuration

🚀 Quick Start

Get your custom Cosmo Router running in under 5 minutes! Choose your preferred approach below.

📁 Examples

Each example is a self-contained router configuration with a custom module. You can copy the example directory to your own repository and start customizing it.

Example	Path	Documentation	Description
Complete Module	examples/complete/	📖 README	Advanced router customization with custom modules and middleware

🔌 Go Production

Packaging and Running the Router

There are two way to produce a deployable artifact:

🐳 Docker Image (Recommended)

Build the image:

docker build \
  --platform linux/amd64 \
  --build-arg TARGETOS=linux \
  --build-arg TARGETARCH=amd64 \
  --build-arg VERSION=$(git describe --tags --always --dirty) \
  --build-arg COMMIT=$(git rev-parse HEAD) \
  --build-arg DATE=$(date -u +"%Y-%m-%dT%H:%M:%SZ") \
  -t myrouter:latest .

Multi-arch builds: The Dockerfile supports multiple architectures. For custom builds, set TARGETOS and TARGETARCH (e.g., darwin/arm64 for Mac M1).

Run the router:

docker run --name myrouter --rm -p 3002:3002 \
  -e LISTEN_ADDR=0.0.0.0:3002 \
  -e DEMO_MODE=true \
  myrouter:latest

Visit localhost:3002 to see your router in action!

Go Binary (Requires Go 1.25+)

Requirements: Go 1.25+

Build & Run:

go mod download
go build -o router main.go && chmod +x router
./router

Visit localhost:3002 to see your router in action!

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Connecting to WunderGraph Cloud

The router requires a graph api token to serve your supergraph. Follow the instructions in WunderGraph Cloud Onboarding to get your token.

🔄 Upgrade Router

You can upgrade the router in each example directory by following the instructions below.

1. Get the commit SHA from releases page
2. Navigate to your router directory (where go.mod exists)
3. Update dependencies:

   cd examples/complete  # your example directory
   go get github.com/wundergraph/cosmo/router@<commit-sha>

Note

Run go get from the directory containing go.mod

🤝 Contributing

Contributions are welcome! Please feel free to submit examples, improvements, and bug fixes.

License

Cosmo is licensed under the Apache License, Version 2.0.