Configuration¶

LLM provider API keys¶

gem-skill uses RubyLLM to generate skills. Set at least one provider API key before running any install command:

export ANTHROPIC_API_KEY="sk-ant-..."   # Claude models
export OPENAI_API_KEY="sk-..."          # GPT models
export GEMINI_API_KEY="..."             # Gemini models

Other supported providers:

Environment variable	Provider
`ANTHROPIC_API_KEY`	Anthropic
`OPENAI_API_KEY`	OpenAI
`GEMINI_API_KEY`	Google Gemini
`MISTRAL_API_KEY`	Mistral
`DEEPSEEK_API_KEY`	DeepSeek
`OPENROUTER_API_KEY`	OpenRouter
`XAI_API_KEY`	xAI (Grok)

gem-skill environment variables¶

`GEMSKILL_DIR`¶

Controls where generated skills are cached.


Default	`~/.gem/skills`
Example	`export GEMSKILL_DIR="/Volumes/shared/gem-skills"`

Useful for sharing a skill cache across machines via a network drive, or for keeping skills in a non-standard location.

`GEMSKILL_MODEL`¶

Controls which LLM model is used when generating skills.


Default	`gpt-5.5`
Example	`export GEMSKILL_MODEL="claude-opus-4-8"`

The --model flag on any command overrides GEMSKILL_MODEL for that single invocation only.

Recommended shell configuration¶

Add to your ~/.zshrc or ~/.bashrc:

export ANTHROPIC_API_KEY="sk-ant-..."
export GEMSKILL_MODEL="claude-sonnet-4-6"   # or whichever model you prefer

Model selection guidance¶

Model	Best for
Claude Opus 4.8	Highest quality skills; comprehensive coverage
Claude Sonnet 4.6	Good balance of quality and speed
Claude Haiku 4.5	Fast, cheap; good for simple gems
GPT-5.5	Default; strong general-purpose coverage

Pass --model MODEL to any install command to override for one run:

gem skill install rails --model claude-opus-4-8
bundle skill install --model claude-haiku-4-5