brunnr install¶

Install skills from the brunnr registry. By default, brunnr shows you the skill content before installing so you can review it.

Usage¶

brunnr install <skill> [--registry URL] [--with-tests] [--force] [--list] [-y]

Arguments¶

Argument	Description
`skill`	Skill slug to install (e.g., `ax-rubric`). Required unless using `--list`.

Flags¶

Flag	Short	Description
`--registry`		Registry URL. Default: `https://github.com/Peleke/brunnr`
`--with-tests`		Also fetch test fixtures from `tests/<slug>/`
`--force`		Overwrite an existing skill without prompting
`--list`		List available skills in the registry
`--yes`	`-y`	Skip the review prompt and install immediately

How it works¶

1. Fetch the skill¶

brunnr fetches SKILL.md from the registry's GitHub raw content URL:

https://raw.githubusercontent.com/{owner}/{repo}/main/skills/{slug}/SKILL.md

2. Review before install¶

Unless --yes or --force is set, brunnr shows you the first 30 lines of the SKILL.md and provides a link to the full source on GitHub. You must type y to proceed.

--- ax-rubric/SKILL.md (first 30 of 142 lines) ---
---
name: ax-rubric
description: Score agent-facing tool descriptions against the AX Description Rubric...
---

# AX Description Rubric - Tool Description Reviewer

You are an agent experience (AX) reviewer...
  ... (22 more lines)

Full source: https://github.com/Peleke/brunnr/tree/main/skills/ax-rubric

Install ax-rubric to ./skills/ax-rubric/? [y/N]

Review your skills

The review step exists for a reason. Third-party skills run as system prompts inside your agent. A malicious skill could instruct the agent to exfiltrate data, ignore safety guidelines, or execute dangerous commands. Always read before installing.

3. Write files¶

brunnr writes the skill to ./skills/<slug>/SKILL.md relative to your current directory. It also checks for an optional JSON schema at schemas/<slug>/output.schema.json in the registry.

4. Fetch test fixtures (optional)¶

With --with-tests, brunnr also fetches:

tests/<slug>/test-spec.json -- The test specification
Any fixture files referenced in the spec's cases[].fixture field

Where files go¶

your-project/
  skills/
    ax-rubric/
      SKILL.md              # The skill prompt
  schemas/
    ax-rubric/
      output.schema.json    # Optional output schema
  tests/
    ax-rubric/
      test-spec.json        # Test specification (with --with-tests)
      fixtures/
        bad-description.json
        good-description.json

Examples¶

List available skills¶

brunnr install --list

Available skills:
  - ax-rubric

Install a skill with review¶

brunnr install ax-rubric

Install without review¶

brunnr install ax-rubric -y

Install with test fixtures¶

brunnr install ax-rubric --with-tests

Fetching ax-rubric from https://github.com/Peleke/brunnr...
  -> skills/ax-rubric/SKILL.md (142 lines)
  -> schemas/ax-rubric/output.schema.json
  -> tests/ax-rubric/test-spec.json
  -> tests/ax-rubric/fixtures/bad-description.json
  -> tests/ax-rubric/fixtures/good-description.json

Installed ax-rubric to ./skills/ax-rubric/

Tip: Run `brunnr eval ax-rubric --dry-run` to validate locally.

Overwrite an existing skill¶

brunnr install ax-rubric --force

Use a custom registry¶

brunnr install my-skill --registry https://github.com/myorg/my-skills

The registry URL must point to a GitHub repository with skills in a skills/ directory.

Exit codes¶

Code	Meaning
`0`	Skill installed successfully
`1`	Error: skill not found, already installed (without `--force`), user aborted, or registry unreachable