⚡ Quick Start

Mobile App

Our iOS native interface is now available on the App Store! Download W&B Catnip to get started. The app will help you configure an existing GitHub repository with catnip as described below. Once setup you can fire up Claude Code on the go!

Github Codespaces / Devcontainers

You can add Catnip to a .devcontainer/devcontainer.json in an existing GitHub repository. This gives you complete control over the environment that claude operates in. If you don't have a devcontainer config, add the following to your repo's github url: /new/main?dev_container_template=1&filename=.devcontainer%2Fdevcontainer.json to create one. Just add the catnip feature and ensure the port is forwarded:

{
  ...
  "features": {
    "ghcr.io/wandb/catnip/feature:1": {}
  },
  "forwardPorts": [6369],
  ...
}

[!TIP] Why 6369 you might ask? Type C A T S on your telephone keypad and you'll find the answer 🤓

Once your codespace is loaded, look for the cat logo in left sidebar. That will allow you to open the catnip interface in a new tab. You can also use catnip from a mobile device! Goto catnip.run and login to your github account. We will automatically start your codespace if needed and then redirect you to the catnip mobile interface. Finally you can vibe code on the go!

[!NOTE] To make this work, catnip pings our service running at catnip.run with the name of the codespace and repo it's running in when it boots up. This means you need to start the codespace from the GitHub UI or CLI at least once to be able to access the codespace on mobile. We also store the temporary GITHUB_TOKEN in our backend so we can verify catnip is running within a private codespace. These credentials are encrypted and pruned every 24 hours, see codespace-store.ts

Local Development

You can also run catnip locally:

curl -sSfL install.catnip.sh | sh
# Optionally start catnip from an existing git repo
cd ~/Development/my_awesome_project
catnip run
# Open http://localhost:6369 🎉

catnip is a golang binary with a vite SPA embedded in it. The wandb/catnip container was inspired by the openai/codex-universal container. Calling catnip run starts the universal container with catnip pre-installed.

It comes pre-configured with node, python, golang, gcc, and rust. You can have the container install a different version of the language on boot by setting any of these environment variables:

# Set specific language versions for AI development
CATNIP_NODE_VERSION=20.11.0
CATNIP_PYTHON_VERSION=3.12
CATNIP_RUST_VERSION=1.75.0
CATNIP_GO_VERSION=1.22

[!NOTE] If you want complete control of your environment, run catnip in a devcontainer as described above

Advanced Setup

Catnip currently looks for a file named setup.sh in the root of your repo and runs it when a workspace is created. This is a great place to run pnpm install, pip install -r requirements.txt, or uv sync - perfect for AI projects with complex dependencies.

#!/bin/bash
pip install -r requirements.txt
pip install openai anthropic chromadb
npm install
# Assuming --dind passed locally, or the docker-in-docker feature was added
docker-compose up -d --build

Environment variables

catnip run accepts -e arguments. For instance if you want to pass ANTHROPIC_API_KEY from your host into the container you can simply add -e ANTHROPIC_API_KEY and then all terminals and AI agent sessions within the container will see that variable. You can also explicitly set variables, -e ANTHROPIC_BASE_URL=https://some.otherprovider.com/v1

catnip run -e ANTHROPIC_API_KEY -e OPENAI_API_KEY -e PINECONE_API_KEY

SSH

The catnip run command configures SSH within the container by default. It creates a key pair named catnip_remote and configures a catnip host allowing you to run ssh catnip or open a remote development environment via the Remote-SSH extension. This works perfectly with Cursor, VS Code, and other editors that support remote development. You can disable ssh by adding --disable-ssh to the run command.

Docker in Docker

If you want the catnip container to be able to run docker commands, pass the --dind flag to the catnip run command. This mounts the docker socket from the host into the container allowing your terminals and AI agents to build or run containers - useful for containerized ML services or complex multi-service applications. If you're running in GitHub codespaces make sure you've

Git

If you run catnip from within a git repo, we mount the repo into the container and create a default workspace. When you start a Claude session in Catnip the system automatically commits changes as Claude makes them.

[!TIP] The workspace within the container is committing to a custom ref refs/catnip/$NAME. For convenience we also create a nicely named branch like feature/make-something-great. This branch is kept in sync with the workspace ref which means you can run git checkout feature/make-something-great outside of the container to see changes locally - perfect for AI-assisted development workflows where you want to review agent changes!

We also run a git server in the container. You will see a Git option in the "Open in..." menu that will provide you with a clone command like:

git clone -o catnip http://localhost:6369/my-sick-repo.git

As you create new workspaces in the container, you can run git fetch catnip back on your host to see your changes outside of the container!

Ports

Catnip forwards ports directly to the host system. When a service starts within the container, Catnip automatically detects and forwards the port, making it accessible at http://localhost:$PORT. Each workspace also has the PORT environment variable set to a known free port. For convenience, services can also be accessed through the Catnip UI proxy at http://localhost:6369/$PORT.

This is especially powerful for LLM and agentic application development where you might have:

• FastAPI backends with LLM integration on port 8000
• React/Next.js chat interfaces on port 3000
• Streamlit data exploration dashboards on port 8501
• Jupyter notebooks for experimentation on port 8888
• Vector databases and other services on various ports

[!NOTE] If a port isn't bindable on the host (e.g., already in use), Catnip will automatically find and use the first available port instead. The UI will notify you of the actual port being used.

🗺️ Roadmap

Coming Soon

• [x] 🎯 Native devcontainer support
• [x] 📱 Mobile UI
• [ ] 🤖 Support for more AI coding agents
• [ ] 🌐 Other cloud native environment

❓ FAQ

Currently optimized for Claude Code, with support for additional AI coding assistants likely coming soon. The architecture is designed to be extensible for the growing ecosystem of AI development tools.