Agent skill · kevmoo
sem-semantic-diff
Use the `sem` CLI to view semantic codebase diffs, evaluate dependency graphs, perform impact analysis, and investigate code history without formatting noise. Use instead of standard git diff/log when analyzing structural code changes.
What it needs
About 4k tokens when loaded.
What this skill does
sem Semantic Diff Skill This skill provides instructions on how to use sem, a semantic version control tool that tracks functions, classes, and types rather than just lines of text. Capabilities & Limitations (What sem Does Well and Does Not Do) What sem Does Well Local Codebase Navigation: Builds a precise semantic dependency graph of all classes, functions, methods, and properties defined within the local repository. Structural Diffs & History: Shows added, modified, renamed, or deleted entities across commits without formatting or whitespace noise. Internal Impact Analysis: Tracing the transitive impact (sem impact) or callers/callees (sem graph) of local entities across the workspace. What sem Does Not Do (Important Limitations) External Dependencies: sem only indexes entities defined within the local repository's source files. It does not parse or track external packages or transitive library dependencies (e.g., from pubspec.yaml, nodemodules, Cargo.toml, etc.). External Impact Analysis: Running sem impact on an external type or class (e.g., DartType or ClassElement from an external package) will fail with error: Entity '...' not found. Workflow for External Packages: If tasked with evaluating how an external package is used across a codebase, do not start with sem. Use standard grep or ripgrep to find import statements and locate local wrapper classes or helper functions. Once local wrapper entities are identified, use sem impact on those local entities to trace their usage across the codebase. Finding Entities (<entityname>) Many sem commands require an <entityname>. You can discover the exact names or IDs of entities in the codebase using the following methods: 1. List entities in a file or directory: Use sem entities [PATH] to see all parsed functions, classes, and types in a specific file or directory. 2. From semantic diffs: When you run sem diff, the output will list the names of the entities that have been added, modified, or deleted. 3. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills kevmoo/sem-semantic-diff