codegraph

A guide for using CodeGraph, a tool that maps files, symbols such as functions and classes, and their relationships in a codebase.

In plain words
What is it for?
Use it to find definitions, callers, and callees; trace how code flows; inspect signatures and source; gather focused context; and assess change impact.
Why use it?
It helps answer structural questions that ordinary text search cannot, such as what calls a function or what may break after a change.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/lagrahhn/codegraph-branch/codegraph
Clone the repo
git clone --depth 1 https://github.com/lagrahhn/codeGraph-branch

Made for: Cursor.

Per session 819 This file is loaded in full into every session.
When invoked 819 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00819 $0.00819
Opus 5 $0.00409 $0.00409
Sonnet 5 $0.00164 $0.00164
Haiku 4.5 $0.00082 $0.00082

Measured yesterday against content hash b7113a7f7a9b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codegraph 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.

Origin

This is a copy

100% identical to codegraph — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.cursor/rules/codegraph.mdc · 40 lines

How it starts

The opening of the file, as written. The whole thing — 40 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CodeGraph

This project has a CodeGraph MCP server (codegraph_* tools) configured. CodeGraph is a tree-sitter-parsed knowledge graph of every symbol, edge, and file. Reads are sub-millisecond and return structural information grep cannot.

When to prefer codegraph over native search

Use codegraph for structural questions — what calls what, what would break, where is X defined, what is X's signature. Use native grep/read only for literal text queries (string contents, comments, log messages) or after you already have a specific file open.

Question Tool
"Where is X defined?" / "Find symbol named X" codegraph_search
"What calls function Y?" codegraph_callers
"What does Y call?" codegraph_callees
"How does X reach/become Y? / trace the flow from X to Y" codegraph_trace (one call = the whole path, incl. callback/React/JSX dynamic hops)
"What would break if I changed Z?" codegraph_impact
"Show me Y's signature / source / docstring" codegraph_node
"Give me focused context for a task/area" codegraph_context
"See several related symbols' source at once" codegraph_explore
"What files exist under path/" codegraph_files
"Is the index healthy?" codegraph_status

Rules of thumb

  • Answer directly — don't delegate exploration. For "how does X work" / architecture questions, answer with 2-3 codegraph calls: codegraph_context first, then ONE codegraph_explore for the source of the symbols it surfaces. For a specific flow ("how does X reach Y") start with codegraph_trace from→to — one call returns the whole path with dynamic hops bridged — then ONE codegraph_explore for the bodies; don't rebuild the path with codegraph_search + codegraph_callers. Codegraph IS the pre-built index, so spawning a separate file-reading sub-task/agent — or running a grep + read loop — repeats work codegraph already did and costs more for the same answer.
  • Trust codegraph results. They come from a full AST parse. Do NOT re-verify them with grep — that's slower, less accurate, and wastes context.
  • Don't grep first when looking up a symbol by name. codegraph_search is faster and returns kind + location + signature in one call.
  • Don't chain codegraph_search + codegraph_node when you just want context — codegraph_context is one call.
  • Don't loop codegraph_node over many symbols — one codegraph_explore call returns several symbols' source grouped in a single capped call, while each separate node/Read call re-reads the whole context and costs far more.
  • Index lag — check the staleness banner, don't guess a wait. When a codegraph response starts with "⚠️ Some files referenced below were edited since the last index sync…", the listed files are pending re-index — Read those specific files for accurate content. Files NOT in that banner are fresh and codegraph is authoritative for them. codegraph_status also lists pending files under "Pending sync".

Read the full file on GitHub · 40 lines

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 · 40 lines · 819 tokens per session scan A b7113a7f7a9b

Subscribe to this mod's changes

codegraph is a cursor rule published in the GitHub repository lagrahhn/codeGraph-branch (2 stars, last pushed 1mo ago), licensed MIT. It adds 819 tokens to every session, about $0.0041 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to codegraph, differing in 0 lines, and is treated as a copy.