The concept tree

The concept tree is a living map of the ideas that appear in your conversations and how they relate. It is generated and updated as you talk — you never build it by hand.

What it shows

• Key concepts, deduplicated: the same idea never appears as two nodes, no matter how many times you return to it.
• Relationships between those ideas: parent-child structure drawn as faint arrows, and typed relations — requires, extends, example of, contrasts with — each with its own color, so structure reads at a glance.
• Coverage: at a glance, what a conversation — or a whole subject — has actually touched.

When it builds

The tree grows from substantive conversation. Concept extraction runs while you talk, and Lunar deliberately skips it when there is nothing to extract: greetings and trivial exchanges produce no nodes. If the tree looks empty, give Lunar more to work with.

[!NOTE] The concept tree runs with every Lunar model — Classic, Creative and Mister all share the same universal tool set. See Models.

How to read it

Treat the tree as a checklist for the topic:

• Walk it from general concepts to specific ones, not the other way around.
• Lonely or unfamiliar nodes are usually your gaps — good candidates for a microchat.
• Use it to decide what to study next, not just to admire what you already covered.

Per chat, and per Space

Each chat grows its own tree. At the Space level, the trees of all the classes are fused into a single knowledge graph — not a flat stack of separate trees:

• The same idea is one node. A concept is recognized as the same even when classes write it with different capitalization or accents.
• Concepts keep all their parents. If a topic appeared in two classes under different parents, it inherits both, so you see how it connects from each path that led to it.
• Relations merge across classes. When different classes relate the same topics, those links appear together in the graph — hierarchy kept subtle, typed relations in color.

The result renders as an interactive graph you can pan, zoom and explore, with a legend for the relation colors.

The Space-level graph also feeds Lunar's memory: covered topics from the graph make new chats aware of what you already learned (see How Lunar remembers).

[!TIP] Don't confuse the two views: the graph answers "what have we covered in this Space?", while the study map answers "what did we see in this specific session?".