Claude Code on the web

Claude Code on the web runs each session on a Linux VM with no access to macOS, so it cannot run Xcode or the iOS Simulator on its own. Set up one cloud environment with the lim CLI, the Limrun skills, and your API key. From then on, Claude builds your iOS app on Limrun's Macs from any of your repositories and runs it on a simulator you open in your browser.

Set up the environment

Open claude.ai/code. In the environment menu below the prompt box, choose Cloud, then Add cloud environment.

Create an API key for this environment first: open console.limrun.com/settings, go to API Keys, and click Create Token. Then fill in the dialog:

• Name: limrun.

• Network access: Full. To allow only specific domains instead, see Restrict network access.

• Environment variables: your key.

  LIM_API_KEY=lim_...

• Setup script: installs the lim CLI, then every Limrun skill into ~/.claude/skills, so Claude has the skills in any repository, including ones that do not commit them. It runs at the start of every session, before Claude Code launches.

  #!/bin/bash
  npm install --global lim
  lim skills install --agents claude --scope global

Anyone who can use the environment can read its variables. Use a key created only for this environment, and delete it in the console if the environment is ever shared more widely than you intended. Sharing the environment with your organization makes the key visible to every member who can use it.

Click Add environment. Below the prompt box, pick the limrun environment and your repository, then ask Claude to build and run your app:

Build this app with Limrun and show it to me on an iOS simulator.

How sessions behave

• Claude picks the build path from the skills. The limrun-xcode skill covers xcodebuild projects and limrun-xcode-bazel covers Bazel workspaces.
• Asking to see the app attaches a simulator. From then on, every successful build installs and relaunches the app on it, and Claude's reply links to the live simulator, which you can tap and type in from your browser.
• Instances outlive the session. The Xcode sandbox and the simulator stay up until your organization's inactivity timeout deletes them. To stop them right away, ask Claude to clean up before you close the session.
• Each new session sets up again. The setup script runs at the start of every session, and Claude starts the build setup over.

Restrict network access

Full network access is the simplest setup. To use Custom instead, keep the default allowlist enabled, since it covers package registries such as npm that the setup script needs, and add Limrun's domains:

*.limrun.com
*.limrun.net

Then add the hosts your own build downloads dependencies from. If a step fails with a network error, add the host it tried to reach and start a new session. For how the levels work, see Anthropic's network access documentation.

Next steps