CLI

The harness binary scaffolds and maintains your harness. Most commands are also available from inside Claude Code via the /harness slash command.

Commands

harness init

Scaffold a fresh harness into the current project. Creates harness/, the .claude/ hooks and rules, .mcp.json, and the gitignored .harness/ audit log. Run once per project, then restart Claude Code and approve the MCP server + hooks.

npx harness init

harness add <type> <name>

Scaffold a new primitive and register it in harness.config.ts. <type> is one of guard, check, or tool; <name> is kebab-case.

npx harness add guard block-pushes
npx harness add check validate-routes
npx harness add tool fetch-weather

harness list

List all /harness subcommands with examples.

npx harness list

harness update

Update library-managed skills, rules, and commands from agent-harness-sdk, preserving your local edits. Run after upgrading the package.

npx harness update

The /harness slash command

Inside Claude Code, the same scaffolding is available as a slash command — this is the recommended way to add primitives mid-session, since the new file lands typed and pre-registered:

/harness add guard block-pushes
/harness add check validate-routes
/harness add tool fetch-weather