cartographer

A code-understanding system that builds a persistent map of a codebase from facts supported by evidence. It represents code structure, behavior flows, different views, and pull-request changes at different levels of detail.

In plain words
What is it for?
Use it to explore how a codebase is organized, trace behavior flows, inspect focused views, and review pull-request changes.
Why use it?
It helps an agent navigate an unfamiliar codebase without relying only on isolated file searches or unsupported assumptions.

Plugin for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Claude Code
/plugin marketplace add miltonian/cartographer
agentmods
npx agentmods add plugins/miltonian/cartographer/plugin
Clone the repo
git clone --depth 1 https://github.com/miltonian/cartographer

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

cartographer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugin/.claude-plugin/plugin.json · 20 lines

What it actually says

{
  "name": "cartographer",
  "version": "0.8.0",
  "description": "Agent-first code understanding system. Builds a persistent world-model of your codebase with evidence-grounded facts, semantic map, behavior flows, perspectives, PR review overlay, and navigable depth via semantic zoom.",
  "author": {
    "name": "Alexander Hamilton",
    "email": "[email protected]"
  },
  "homepage": "https://github.com/miltonian/cartographer",
  "repository": "https://github.com/miltonian/cartographer",
  "license": "MIT",
  "keywords": [
    "code-understanding",
    "world-model",
    "semantic-map",
    "codebase-visualization",
    "evidence-grounded"
  ]
}
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 20 lines scan A d650e267442c

Subscribe to this mod's changes

cartographer is a plugin published in the GitHub repository miltonian/cartographer (1 stars, last pushed 2mo ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.