Agent Island

Agent Island is a native status companion for developers who use Claude Code and Codex. It watches local coding-agent session state and makes the current handoff visible, so you can see whether a session is working, waiting for input, or finished without repeatedly checking terminal windows.

The product is designed for people who run several long-lived coding sessions at once. Agent Island collects those sessions into one desktop view and sends a your-turn alert when a supported agent needs attention. That lets developers step away from the terminal, work in another app, or follow a different session while still catching the moment when an agent stops and hands control back.

Agent Island uses native desktop implementations for macOS and Windows. The two applications share the same product contract while keeping platform-specific monitoring code. On macOS, filesystem events help wake the monitor quickly. On Windows, FileSystemWatcher provides the corresponding native signal. A bounded polling fallback remains in both designs because operating-system notification streams can coalesce events, miss newly created roots, or overflow under heavy activity.

The state classifier reads recent local transcript evidence rather than treating every filesystem callback as meaningful. It recognizes supported Claude Code and Codex completion markers, rejects error-shaped or sidechain events that should not complete the foreground session, and uses stable turn identifiers to avoid duplicate alerts. Newer user input revokes an older completion result, so the newest meaningful event determines the displayed state.

Privacy is a product boundary. Session data is processed on the device and is not uploaded to Agent Island. The app does not send project files, prompts, or source code to an Agent Island service. This makes it suitable for developers who want a practical handoff signal without adding a cloud observer to their coding workflow.

Agent Island is open source under the MIT License. The public repository contains the native Swift and C# implementations, release history, issue tracker, and contribution paths. The current stable release is v1.7.1, with downloadable macOS and Windows packages available from GitHub Releases.

Core use cases include monitoring parallel Claude Code and Codex sessions, reducing unnecessary terminal checks, receiving a clear alert when user input is required, and keeping session awareness local. Agent Island is a companion rather than an autonomous runner: it reports state and handoffs, but it does not resume agents, execute commands, or claim that a coding task succeeded.