Repo Map

A navigable map of your codebase for coding agents — so they stop reading whole files just to find their bearings.

repo-map is a Model Context Protocol (MCP) server. It parses a repository into a symbol graph, ranks every symbol by importance (a tuned PageRank), and exposes a handful of tools that let an agent like Claude Code locate code and read only the symbol it needs — instead of loading entire files to orient itself.

Think of it as an "Obsidian for your codebase": an outline + a reference graph + an importance sort, queryable without opening the files.

Why

Reading whole files to understand where a piece of logic lives is the single biggest source of wasted context in agentic coding. On a real exploration workflow over an unfamiliar Python repo, routing that navigation through repo-map instead of raw file reads measured:

Metric	Result
Total workflow token cost	−33 % (up to −52 % cold)
Context loaded into the model	−64 %
outline vs a full file read	−96 %

The gains come from never paying for a file body you don't end up editing.

Tools

Tool	What it does
index(path)	(Re)target the server on a repo and build its map.
where_is(query)	Find where a symbol is defined, by name (substring, case-insensitive), ranked by contextual PageRank.
grep_code(pattern)	Regex search by content — each hit situated in its enclosing symbol (def/class/<module>), not a bare line.
outline(file)	Table of contents of a file: class/function signatures + line ranges. ~95 % fewer tokens than reading it.
get_symbol(file, name)	The full body of a single symbol — the only thing you actually read to start coding.
who_references(name)	Who calls a symbol (what a signature change might break).

Languages

Python, JavaScript/JSX, TypeScript/TSX — via precompiled tree-sitter grammars (no C toolchain required, including on Windows).

Install

git clone https://github.com/noambinabout-boop/repo-map.git
cd repo-map
python -m venv .venv
# Windows:  .venv\Scripts\activate
# Unix:     source .venv/bin/activate
pip install -r requirements.txt   # or: uv pip install -r requirements.txt

Wire it into Claude Code

Register the server (adjust the paths to your clone):

claude mcp add repo-map -- /path/to/repo-map/.venv/bin/python /path/to/repo-map/server.py

Then, from any session:

index("/path/to/the/project/you/want/to/explore")
where_is("MyClass")
outline("src/app.py")
get_symbol("src/app.py", "MyClass")

The server also runs standalone over stdio (python server.py) for any MCP-compatible client.

How it works

• Symbol graph. tree-sitter parses each file into definitions and a call/reference graph.
• Importance ranking. A PageRank variant weighted against popularity (1/fan-in) so ubiquitous helpers don't drown out the code that actually structures the repo, merged with the import graph so shared components/constants aren't invisible.
• Scope resolution. self/cls/this, class inheritance (Python & JS/TS extends), named/namespace/default imports, and light type inference (x = Ctor(); x.foo() → Ctor.foo) are resolved to the right target. Every resolution is conservative: when a target is ambiguous, it falls back to a broad edge rather than dropping one — it never loses an edge, at worst it adds one.
• Incremental cache. Parses are cached per file by mtime in ~/.repo-map/cache/ (override with REPO_MAP_CACHE). Nothing is written into the repos you target. First index of a 284-file TS project: ~17 s; subsequent: ~0.3 s.
• Per-repo ignores. Drop a .repomapignore (.gitignore syntax) at a repo root to keep generated/vendored dirs out of the graph.

Limitations (honest)

• PageRank is sharper on Python than on React/Expo. Structure there flows through JSX/imports/hooks, which the call graph doesn't see. The import-graph merge fixes "invisible shared components," but entry-point screens referenced only once by a route table can still rank low.
• Name-based resolution outside the cases above may add a spurious edge; it never drops one.
• Python from . import x (no module name) is not resolved.
• repo-map indexes structure, not literals — use grep_code for flags/config strings.

Tests

./.venv/Scripts/python.exe tests/run_tests.py

A non-regression suite of fixtures freezes each scope-resolution feature and compares the exact set of graph edges.

Prior art

The "repo map" idea was pioneered by Aider. repo-map is an independent MCP implementation with its own ranking, conservative scope resolution, and per-file incremental cache.

License

MIT