learnlance 🧠🔍

A learning companion for Claude Code. Every time Claude finishes a turn and has generated or edited code, learnlance quietly:

1. reads the session transcript and pulls out the code that was just written,
2. asks Claude "what concepts could a developer learn from this?" — e.g. "you used a delta function, here's what delta encoding is",
3. merges those concepts into a persistent knowledge graph, and
4. regenerates an interactive HTML graph you can open any time.

No API key required. By default it reuses the claude CLI you're already logged into (your Claude Code subscription), so there's nothing extra to set up.

So instead of code just appearing, you build up a visual map of everything you've picked up along the way — new nodes light up as 🌱 new topics learned.

Why it won't slow you down or break your session

• The API call runs in a detached background process — Claude Code never waits.
• The hook is wrapped so any failure is logged and swallowed; it can never interrupt your coding session.
• Turns with no substantive code make no API call (no cost, no noise).

Install (no pip, no API key)

# just install the Claude Code Stop hook — it uses your logged-in `claude`
python -m learnlance install

Run this from the learnlance/ project folder. That's it — start (or restart) Claude Code and code as usual.

If claude isn't on your PATH, point learnlance at it:

python -m learnlance config --claude-bin "C:\path\to\claude.cmd"

Prefer a global learnlance command? pip install -e . in this folder, then use learnlance instead of python -m learnlance everywhere.

Prefer a direct API call instead of the CLI? learnlance config --backend api --set-key sk-ant-...

Use it

learnlance show      # render + open the interactive knowledge graph in your browser
learnlance list -v   # list learned concepts (with explanations) in the terminal
learnlance stats     # quick counts, broken down by category
learnlance help      # show every available command

The show view opens with a live loading spinner while it renders, then two declutter controls in the sidebar: show related concepts (reveal the dimmed umbrella nodes) and a min link strength slider (hide one-off links).

Add a concept Claude missed

learnlance add "debouncing"                 # searches the current dir for the topic
learnlance add "topological sort" --path ./src
learnlance add "event sourcing" --force     # add even if it's not found in the code

learnlance greps your codebase for the topic, sends the matching snippets to Claude, and adds the concept (and any tightly-related ones actually present) just like the hook does.

Clear the graph

learnlance clear "delta encoding"   # remove one concept (and any orphaned related nodes)
learnlance clear                    # wipe the entire graph (asks first; -y to skip)

Per-session markdown recaps are written to ~/.learnlance/insights/<session>.md.

Configuration

learnlance config                      # show current settings
learnlance config --cli-model haiku    # make the cli backend use a faster model
learnlance config --max-topics 3       # fewer concepts per turn
learnlance config --background off      # run inline (blocks until analysis is done)
learnlance config --disable             # pause without uninstalling the hook
learnlance config --backend api --set-key sk-ant-...   # switch to the API backend

Everything lives under ~/.learnlance/: graph.json (the graph), graph.html (the visualization), insights/ (markdown recaps), learnlance.log (diagnostics).

Uninstall

python -m learnlance uninstall

How it works (internals)

Zero third-party dependencies by design — the hook must run reliably wherever Claude Code launches it.