How to share memory between Claude Code, Codex and Cursor with Beacon

Beacon by Asymptote Labs is an open-source, local-first memory layer that captures session history from Claude Code, Cursor, Codex, OpenCode, Cline and 20+ other harnesses into one OpenTelemetry-based trace format. It solves the problem that a fix for a mistake in one harness needs to be relearned in another. Beacon records prompts, responses, commands and file edits, allowing users to replay exact agent activity and send activity to a Security Information and Event Management (SIEM) system.

To set up Beacon in Local mode, users can follow a guide that covers installation on macOS, Linux, and Windows. The installation process varies slightly between operating systems. For macOS, the fastest path is to let the coding agent do the installation using a command in Claude Code, Codex or Cursor. For Linux, the installer can be run from the terminal. For Windows, the MSI installer can be downloaded and run.

Once installed, Beacon can be accessed locally through a dashboard or by reading raw event stream directly. It can also recall memory from another agent and forward agent activity to a SIEM. Beacon captures session history in the background, and users can check what it has captured using the `beacon traces` command. Users are advised to curate what Beacon extracts, as the review step is important. The guide also suggests installing lenses for additional functionality, but warns to only install trusted lenses.