Codespaces idle timeout and resource consumption limits

GitHub Codespaces defines activity based on user interaction and data synchronization rather than the execution of background CPU processes. If a process is running in the terminal but not generating specific interactive signals, the environment may still suspend once the idle timeout is reached.

Activity Triggers for Timeout

GitHub monitors several signals to determine if a Codespace is "active." The following actions typically reset the idle timeout timer:

• Editor Interaction: Keystrokes mouse movements within the web-based IDE or a connected VS Code instance.
• File Synchronization: Automatic saving of files or changes being synced to the remote filesystem.
• Network Traffic: Active outbound network requests initiated by the environment (e.g., API calls).
• Terminal Input: Sending commands to the terminal and receiving standard output that updates the session.

Note: A background process (such as a long-running build, test suite, or data processing script) that consumes CPU but does not produce interactive I/O or network traffic is not considered activity by the idle monitor.

Notifications and Alerts

There is currently no native notification alert or warning system that triggers a moments before the idle timeout initiates a suspension. The environment transitions to a suspended state immediately once the duration defined in your settings expires.

How to Manage Long-Running Workloads

To prevent background tasks from being interrupted by idle suspension, consider these strategies:

1. Adjust Timeout Settings: Navigate to Settings > Codespaces > Idle timeout to increase the duration (up to 240 minutes). Be aware that this will increase compute hour consumption.
2. Heartbeat Scripts: For tasks that must stay active, some users use a script that performs a minor network request or file write every few minutes to simulate activity, though this increases costs.
3. Process Persistence: Since volatile memory is lost during suspension, ensure your workflows use tools like tmux or screen and are designed to resume or checkpoint their state once the environment is restarted.