Add Skill

What it does

When your agent uses it

• References a GitHub URL/repo to fetch from (e.g.
• /add-skill https://github.com/OpenHands/extensions/tree/main/skills/codereview
• Add the codereview skill from https://github.com/OpenHands/extensions/)

Example prompts

• “add the codereview skill from https://github.com/OpenHands/extensions/”
• “/add-skill”

Requirements

• Python 3
• A credential in GITHUB_TOKEN

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

1. 1Parse the URL to extract repository owner, name, and skill path
2. 2Fetch the skill using the bundled script. Run it from this skill's
3. 3Verify that SKILL.md exists in the destination
4. 4Inform the user the skill is now available

What it can do on your machine

Read from SKILL.md and the folder at commit d008b81. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships 1 file in scripts/ (Python), which the agent can run.

  Shell commands in SKILL.md call:

  • python3

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Hosts in commands or code, which the agent is likely to contact:

  • github.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names these keys or tokens, usually read from environment variables:

  • GITHUB_TOKEN

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Add Skill loads about 560 tokens when it runs. Until then it costs about 132 tokens; SKILL.md has 152 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~132

When it runs · the whole SKILL.md, loaded when a task matches

~560

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from OpenHands/extensions at commit d008b81, republished under its MIT licence (© OpenHands). 152 words, ~560 tokens.

name

add-skill

description

Import an existing skill from a GitHub repository URL into the current workspace. Use only when the user provides or references a GitHub URL/repo to fetch from (e.g., `/add-skill https://github.com/OpenHands/extensions/tree/main/skills/codereview` or "add the codereview skill from https://github.com/OpenHands/extensions/"). Handles fetching the skill files and placing them in .agents/skills/. This does not author new skills — to create a new skill from scratch (no source URL), use the skill-creator skill instead.

# Run the fetch script
python3 scripts/fetch_skill.py "https://github.com/OpenHands/extensions/tree/main/skills/codereview" "/path/to/workspace"

# Verify installation
ls /path/to/workspace/.agents/skills/codereview/SKILL.md

© OpenHands, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 5 other files (scripts) in skills/add-skill of OpenHands/extensions.

• SKILL.md
• .claude-plugin
• .codex-plugin
• .plugin/plugin.json
• README.md
• scripts/fetch_skill.py

Open the folder on GitHubat commit d008b81