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Getting started

These guides take you from nothing installed to a small, always-on agent setup running on your own Mac or Linux box. By the end you will have:

  • Harness, supervising agent CLIs (Claude Code, Crush, Codex) as a service. It restarts them when they fall over, fires scheduled sweeps on a cron, and lets you attach to any of them from a terminal or over SSH.
  • Switchboard, turning webhooks into durable todos. It pushes those todos to your always-on agents the moment they arrive, so the agents don't poll.
  • Cairn, giving your agents a place to publish reports and handoffs as shareable links.

You do not need all three. Harness is useful on its own from the first page; Switchboard and Cairn slot in when you want real-time work and shareable output.

The path

Read these in order the first time; each one assumes the previous.

#GuideYou finish with
1Installharness on your PATH, verified with harness doctor
2Run the daemon as a servicethe supervisor surviving logout and reboot (systemd or launchd)
3Your first supervised agenta Crush or Claude Code session you can attach to, restart, and read logs from
4Scheduled sweepsan unattended agent run on a cron, with outcomes you can trust
5Push events with MCP channelsan always-on agent that wakes on a Switchboard todo
6Observabilitypost-mortems with harness logs, the chatroom, doctor, and the SSH cockpit
7How Harness, Switchboard and Cairn fit togetherthe whole loop, end to end
Troubleshootinganswers for the usual "it's green but nothing happens" moments

The Usage section is the reference behind these guides: every verb, every config key, every flag.

Before you start

  • A Mac or a Linux box you can leave running. A laptop works; scheduled sweeps notice when it wakes from sleep.
  • At least one agent CLI, installed and logged in as the same user that will run Harness: Claude Code, Crush, or Codex.
  • Credentials for that agent, such as $ANTHROPIC_API_KEY or a prior interactive login. Harness never asks for them. It just starts the CLI with the environment you give it.

:::note Version

These guides track main. Several features they use are newer than the latest tagged release: CRON_TZ, catch_up, timeout, on_overlap, keep_runs, prompt_file, run history, the agent-activity view of harness logs, and the chatroom. Install shows how to build from main until a release catches up.

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