Mycelium: Your AI Coder's GPS for Codebase Navigation

The Problem Nobody Talks About

Let me paint a picture. You fire up your AI coding assistant and ask it to add a new feature. What happens next? The agent dives into your project, frantically opening files—sometimes dozens of them. Twenty minutes pass. It's read through authentication modules, utility files, legacy code nobody touches anymore, and configuration files. And what does it produce? Code that completely ignores how your project actually works.

Sound familiar? This is the dirty secret of AI-assisted development. These tools are powerful, but they're flying blind inside your codebase.

Why Context Is Everything

Here's the uncomfortable truth: AI agents are only as smart as the information you give them. Hand them the right details, and they'll write clean, appropriate code. Dump a mountain of unrelated files in front of them, and you'll get gibberish that needs rewriting from scratch.

The core issue? Most AI coding tools have zero idea about your project structure when they start. They don't know which files contain your core business logic, which ones handle authentication, or which are just old code nobody should touch. So they improvise—opening files alphabetically, or by import order, or whatever strategy seems reasonable. It's messy, time-consuming, and rarely works well.

Mycelium's Approach

This is exactly where Mycelium comes in. Instead of letting your AI assistant wander through your code like a lost tourist, it builds a detailed map of your entire project. Every file, every dependency, every connection between them—cataloged and ready to query.

The magic happens in two steps. First, you run npx @kopikocappu/mycelium init just once. Mycelium analyzes your whole codebase, traces all the imports, and constructs a complete dependency graph. It even uses a lightweight AI model (Claude Haiku) to write human-readable descriptions for each file.

Then, before your AI assistant tackles anything, it runs /preflight with a description of the task. Mycelium hands back exactly the files that matter—no more, no less.

Features That Actually Help

Mycelium isn't just a fancy file search. It brings several genuinely useful tools to the table.

Live graph viewer — Open your browser and watch your entire codebase come alive. Files appear as connected nodes, imports become visible links. You can see your project's architecture at a glance. For new team members trying to understand a complex project, this alone justifies the setup.

Agent change history — Every file modification gets logged with timestamps, task descriptions, and which agent made the change. Finally, you have an audit trail. You can actually track what your AI assistants modified—and when.

Semantic search — Search by concept, not keywords. Looking for files related to "payment processing"? Mycelium finds them even if none of the files actually contain the word "payment." This is a lifesaver for larger codebases where naming conventions have shifted over the years.

A Note on Privacy

Enterprise users, take note: Mycelium runs entirely on your local machine at localhost:47821. Your code never leaves your development environment. This isn't some cloud service that analyzes your proprietary logic. It's a local tool that minds its own business.

Should You Bother?

Look, if you're working on a tiny personal project with just a handful of files you already know by heart, Mycelium might be unnecessary complexity. You probably don't need a dependency graph for a five-file script.

But if you're part of a team, maintaining a larger codebase, or constantly watching your AI assistant struggle to find the right files—you'll feel the difference immediately. The initial setup takes a few minutes. The time saved over weeks and months of development is substantial.

The Bottom Line

The promise here is straightforward: your AI coding assistant, finally equipped with a map instead of a blindfold. Four relevant files instead of forty. No more guessing. Code that actually respects your project's architecture.

If you've ever been frustrated watching a supposedly smart AI agent completely miss the point, Mycelium might be exactly what you've been looking for.