Anthropics February 2026 AI Fluency Index studied 9,830 Claude conversations and classified 11 observable behaviors across three axes: Description, Discernment, and Delegation. I read it and immediately wanted to know where my own sessions landed — not the population, mine.

skill-tree does exactly that. Install it in Claude Code, run it, and it classifies your session history against the same 11-behavior taxonomy from Dakan & Feller's 4D AI Fluency Framework. You get a visualization showing which behaviors show up in your work and — more usefully — which ones you've never touched.

The output is a character archetype card rendered as a tarot card with museum art, served at a stable URL from Fly.io. Seven possible archetypes. Mine was Illuminator; you can see what the card format looks like at skill-tree-ai.fly.dev/fixture/illuminator.

The part I actually use day-to-day: a growth quest. The classifier picks one behavior from the 11 that's absent or weak in your history and surfaces it at the start of your next session via a SessionStart hook. It persists in ~/.skill-tree/ across sessions so it doesn't reset every time.

Install in Claude Code:

claude plugin marketplace add robertnowell/ai-fluency-skill-cards && claude plugin install skill-tree-ai@ai-fluency-skill-cards

Also works in Cowork via skill-tree-ai.zip, and available as an MCP server (npm install skill-tree-ai) for Cursor, VS Code, and Windsurf. End-to-end classification takes 30–60 seconds.

github.com/robertnowell/skill-tree