GEO is the idea that AI search engines (ChatGPT, Perplexity, Claude) cite content differently than Google ranks it. Things like question-formatted headings, FAQ sections, entity density, E-E-A-T signals, and citation-ready statistics all matter for whether an LLM will pull from your content. geo-lint has 35 rules specifically for this.
The interesting part is the lint loop. It ships as a Claude Code skill — you run /geo-lint audit and it spawns parallel subagents, one per file. Each agent reads the violations, edits the content, re-lints, and repeats until clean (max 5 passes). The linter is fully deterministic (no LLM in the rules themselves), so the agent gets unambiguous violation + suggestion pairs to act on. Zero hallucination risk in the analysis layer.
It also works without Claude Code — npx geo-lint --format=json gives you a flat JSON array any agent (Cursor, Copilot, Windsurf) can consume. The rules are the same either way.
MIT licensed, zero runtime deps beyond gray-matter. npm: @ijonis/geo-lint