Agent Beacon: Open-source telemetry layer for AI agents AI coding agents such as Claude Code, Codex CLI, Cursor, and Claude Cowork run on developer laptops, CI jobs, cloud environments, where they edit files, run commands, and call outside tools. Beacon, an open-source project from Asymptote Labs, configures telemetry for those runtimes and writes a normalized record of what each agent does across local, CI, and cloud-agent surfaces. What Beacon collects Beacon discovers supported local runtimes on a host and configures data collection for them, while also supporting additional CI and cloud-agent telemetry paths. It configures supported runtimes such as Claude Code and Codex CLI to export OpenTelemetry data to a collector running on localhost. For Cursor, it installs hooks that emit local endpoint events covering sessions, prompt submission, tool use, command execution, MCP-like tool activity, approval decisions, and file edits where Cursor exposes those payloads. A bundled collector converts the OpenTelemetry logs and hook events into a normalized JSON event log, and a local dashboard reads that log for inspection. Teams can also forward the data into supported customer-managed SIEMs. The software runs locally and works without an Asymptote account. It records full telemetry by default, with configurable retention modes for leaving out prompt text, raw attributes, command output, and raw diffs. Two added retention modes exist: a redacted mode that includes configured content fields after local redaction and size limits, and a third mode that keeps configured content fields in local or customer-controlled logs, subject to event size limits. The dashboard binds to loopback and reads the runtime log. Written mostly in Go and released under the MIT license, Beacon installs on macOS through a Homebrew tap. Claude Cowork support requires OpenTelemetry export configured by a Team or Enterprise admin in the Claude admin console, with an OTLP endpoint