Getting started

Which tool are you on?

Claude Code → follow this page. Cursor, Kiro, or Codex CLI → the install steps differ (no plugin marketplace on those tools yet) — see Other coding agents instead.

Install (Claude Code)

No clone, no shell script — install the plugin from inside Claude Code:

/plugin marketplace add addit-digital/addit-harness
/plugin install addit-harness@addit
/addit-harness:setup

The plugin (agents/, skills/) tracks the repo via git automatically — no re-run needed to pick up updates.
/addit-harness:setup places the parts a plugin can’t carry natively (CLAUDE.md, AGENTS.md, rules/, references/, settings.json) — run it once after installing, and again after an update to re-sync. Add --scope project to confine it to the current project instead of ~/.claude (default), or --link to symlink instead of copy.
The plugin itself can also be scoped: /plugin install addit-harness@addit --scope local keeps it to just the current repo; --scope project shares it with collaborators via that repo’s .claude/settings.json; default --scope user is global.

The `@addit-harness:` namespacing gotcha

Plugin-provided agents are namespaced — invoke them as @addit-harness:code-reviewer, not bare @code-reviewer. This is the most common “why isn’t this working” moment for new installs. See Subagents for the full list.

Verify it worked

Run /help — you should see @addit-harness:code-reviewer and the other eleven subagents listed under Agents. If they’re missing, re-run /addit-harness:setup and check the plugin installed without errors.

Alternative: copy-based install

Prefer the old copy-based install instead? ./install.sh --target claude still works — see Other coding agents for the general install.sh flags. It’s no longer run automatically by a plain ./install.sh with no arguments.

New to the mental model? Read Concepts next.
Want to know what each subagent does? Read Subagents.