Claude
Download the skill folder from https://github.com/obra/superpowers and upload it as a ZIP in Settings → Capabilities → Skills. In Claude Code, copy it to ~/.claude/skills/test-driven-development/.
ChatGPT
Paste the SKILL.md content into a Project's instructions or a Custom GPT. Or connect the AI Skill Directory MCP server (https://aiskilldir.com/mcp) and ask: "get skill test-driven-development".
Gemini
Paste the content into a Gem's instructions, or reference it from GEMINI.md in Gemini CLI.
Codex / Cursor
Save it under your repo's skills folder and reference it from AGENTS.md.