IUM: MCP Symbol Indexer Cuts AI Agent Token Usage by 15.9x vs grep

IUM is a two-pass AST walker that builds an SQLite database of every symbol event — definitions, call sites, mutations — then exposes the index over the Model Context Protocol (MCP) as tools for Claude Code, Cursor, or any MCP client. Instead of grep dumping thousands of lines into context, agents get exact file:line coordinates, call graph tracing, and semantic search.

Why this exists

Claude Code was burning context windows by making repeated grep calls across unfamiliar codebases — reading dozens of files to find a single function. IUM replaces that with a prebuilt index queried via MCP.

Benchmark: token cost

Tested against the DataFusion codebase (1,538 files, Rust). Four equivalent queries were run with grep versus IUM:

• Grep: 82,645 tokens
• IUM: 5,190 tokens
• Ratio: 15.9x fewer tokens

Caveat from the author: grep wins on raw execution speed. IUM wins on token cost at volume. For one-off scripts, use grep. For AI agents making thousands of calls, the math favors IUM.

Technical details

• Two-pass AST walk → SQLite matrix of symbol events
• Exposes MCP tools for trace, search, and coordinate lookup
• Everything runs locally — your code never leaves your machine
• Supported languages: Rust, Python, TypeScript, CSS, HTML

Usage

Install from copecode.dev. Works with Claude Code, Cursor, or any MCP client out of the box.