Gograph: Stop letting AI agents hallucinate your Go code (How to ditch grep for AST)

If you’ve been using Claude Code, Cursor, or custom MCP servers to navigate large Go repositories, you’ve probably hit the "Context Wall."

By default, AI coding agents navigate codebases using standard CLI tools like grep, cat, and find. In a compiled, strongly-typed language like Go, this creates two massive bottlenecks:

1. Massive Token Waste: To find a single struct definition, the agent greps a keyword, gets hundreds of noisy results, and decides to cat a 1,500-line file just to read a 10-line struct.
2. Duck-Typing Hallucinations: Because Go uses implicit interfaces, grep is practically useless for answering the question: "Which structs actually implement the AuthService interface?" The agent ends up hallucinating implementations based on naming conventions.

I got tired of watching Claude burn thousands of API tokens reading noisy tests and dependency injection wiring just to find a simple factory function.

So, I built Gograph.

What is Gograph?

Gograph is a local, CLI-based AST and type-aware repository indexer built specifically for AI agents.

Instead of letting the LLM wander blindly with string-matching tools, you instruct it to use gograph for semantic, structural extraction. It performs no network calls, runs instantly, and outputs strictly formatted, machine-parseable JSON or text.

The Token-Saving Commands

With Gograph in your $PATH, agents can now do surgical extractions:

• Find interface implementers: gograph implementers "AuthService"
• Extract a function body (without reading the file): gograph source "ValidateToken"
• Calculate blast radius before a refactor: gograph impact "printResults"
• Bundle all context in one call: gograph context "User" (Returns the AST node, exact source code, upstream callers, downstream callees, and related tests in a single token-optimized prompt).

How to integrate it with Claude Code or Cursor

The easiest way to supercharge your agent is to add a strict rule to your repository's CLAUDE.md or .cursorrules file to override its default behavior.

First, install the binary:

brew tap ozgurcd/tap
brew install gograph

Then, paste this block into your CLAUDE.md or .cursorrules:

## Repository Navigation (CRITICAL)
This project is indexed using `gograph`. **DO NOT use `grep` or `cat` for structural Go code analysis.**

1. Always run `gograph build .` at the start of your session to ensure the index is fresh. If the codebase is in a compilable state, use `gograph build . --precise` instead to enable strict type-checked interface analysis.
2. To find interface implementers, run: `gograph implementers <InterfaceName>`
3. To extract a function body or mock stub without reading the whole file, run: `gograph source <SymbolName>`
4. To see where a function is called, run: `gograph callers <FunctionName>`
5. Use `grep` ONLY for string literals, configuration files (.env), or markdown documentation.

Native MCP Support

If you prefer not to use CLI instructions, Gograph also ships with a native Model Context Protocol (MCP) server. Running gograph mcp . exposes all of these commands natively to Claude Desktop over stdio!

---

I built this to scratch my own itch during a heavy Go refactor, but it completely changed how I interact with LLMs in compiled codebases.

If you are building AI agents or just want Cursor to stop hallucinating your interface bindings, I'd love for you to give it a spin! You can check out the source code, installation instructions, and full feature list on GitHub.

Let me know what you think, and I'm happy to answer any questions about the AST heuristics!