Vesalius

Vesalius, made by Haplo, LLC, indexes a repository locally on a Mac and builds a code graph of how files, symbols and calls connect. It exposes that graph to Claude Code and other MCP clients through five read-only tools, and also ships a CLI, a Mac app and a VS Code extension. The latest release listed is v2.1.0.

What It Is

Vesalius is a code-intelligence tool that reads a repository once and stores the result in a local SQLite index. Instead of an AI assistant chaining searches and file reads, it can ask Vesalius who calls a function, what a file contains, or where a feature lives, and get answers with file and line references. The README states that indexing runs on the Mac and that Vesalius itself does not upload code.

The five MCP tools

• usages: callers and uses of a symbol or file, including type-inferred uses, with a completeness check and, for rename, signature or remove changes, an edit list and tests to run.
• feature_map: core types and functions for a feature question, grouped by role.
• outline: declarations, signatures and line ranges for a file, type or function.
• architecture: targets, packages, dependency direction and cycles.
• dependency_cycles: circular imports in scope.

The same queries are available from the terminal, along with commands such as ask, impact, health, hotspots, unused, map and watch.

Setup path

Installation is via Homebrew followed by vesalius setup. Setup registers the MCP server with Claude Code (and Codex if installed), adds a permission rule for the read-only tools, and indexes the current repository. vesalius setup --undo reverses it, and vesalius doctor and stats check the connection and show what Claude asked. It requires a Mac with Apple silicon on macOS 15 or later. Cursor and other stdio MCP clients can be registered manually.

Mac app and VS Code

The Mac app shows an overview, a clustered dependency system map, a health score with explained deductions, and plain-English ask. It can also run Claude Code or Codex on a finding in plan-only or edit mode. The VS Code extension adds health, current-file and hotspot views, Problems-panel findings, CodeLens, change-impact commands and MCP registration for agent mode.

Benchmark and language support

The authors report a benchmark of 20 questions over 6 codebases in which Claude Code with Vesalius used a median 51% fewer tokens, with no measurable change in overall answer quality; answers about where a feature lives scored 2.1 points lower. Swift gets a full syntax-tree analysis. TypeScript, JavaScript and Python use tree-sitter. Other languages are read lexically without a call graph.