Agent skill · data analytics · lum1104
understand-diff
Use when you need to analyze git diffs or pull requests to understand what changed, affected components, and risks
Why this skill is useful
Provides specific commands and procedures for analyzing git diffs against a knowledge graph, which the AI wouldn't reliably generate on its own.
What it needs
About 3k tokens when loaded. Last updated 2026-07-30. 77,791 stars on the source repository.
What this skill does
/understand-diff Analyze the current code changes against the knowledge graph in the project's data directory (.ua/knowledge-graph.json, or the legacy .understand-anything/knowledge-graph.json when that directory is present). Graph Structure Reference The knowledge graph JSON has this structure: project — {name, description, languages, frameworks, analyzedAt, gitCommitHash} nodes[] — each has {id, type, name, filePath?, summary, tags[], complexity, languageNotes?} Code node types: file, function, class, module, concept Non-code node types: config, document, service, table, endpoint, pipeline, schema, resource Domain/knowledge node types: domain, flow, step, article, entity, topic, claim, source IDs use the node type as prefix, e.g. file:path, function:path:name, config:path, article:path edges[] — each has {source, target, type, direction, weight} Key types: imports, contains, calls, dependson, configures, documents, deploys, triggers, containsflow, flowstep, related, cites layers[] — each has {id, name, description, nodeIds[]} tour[] — each has {order, title, description, nodeIds[]} How to Read Efficiently 1. Use Grep to search within the JSON for relevant entries BEFORE reading the full file 2. Only read sections you need — don't dump the entire graph into context 3. Node names and summaries are the most useful fields for understanding 4. Edges tell you how components connect — follow imports and calls for dependency chains Instructions 1. Resolve the data directory $UADIR. Run UADIR=$([ -d .understand-anything ] && echo .understand-anything echo .ua) — this is the legacy .understand-anything/ when it already exists, otherwise the new .ua/. Check that $UADIR/knowledge-graph.json exists. If not, tell the user to run /understand first. 2. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills lum1104/understand-diff