CodeMeridian: Giving AI Coding Agents a Project Map Before They Edit

AI coding agents feel sharp when a project is small. They can scan a few files, understand the shape, and make useful changes. In that phase, the project still fits inside the agent’s short-term memory. The architecture is obvious. The dangerous files are nearby. The blast radius is small. But something changes when a project reaches MVP size. The agent still sounds confident, but it starts guessing. It finds a nearby file and assumes it is the right one. It trusts stale documentation. It misses hidden callers. It forgets architecture boundaries. It edits something that was not really part of the task. I kept running into that problem while building larger projects. Source-level guardrails help. A CONTRIBUTING.md, AGENTS.md, or project instruction file can tell the agent how to behave. But those are still instructions. They are not facts. That is where the idea for CodeMeridian came from. What CodeMeridian is CodeMeridian is a local code knowledge graph for AI coding tools. It indexes a codebase into Neo4j and exposes that graph through MCP, so tools like GitHub Copilot, Claude Code, Codex-style agents, or other MCP-compatible clients can ask better questions before editing. The basic idea is: The assistant is the AI. CodeMeridian is the project map. It does not replace the coding assistant. It gives the assistant a structured way to ask about the codebase. Examples: What calls this method? What tests cover this area? What files are likely in scope for this feature? Is the graph stale before I trust it? How is this frontend component connected to backend code? Why a graph? Code is already a graph. Methods call methods. Classes implement interfaces. Tests cover production paths. Frontend components call API clients. API handlers touch services. Services use repositories. Docs mention symbols. Projects depend on other projects. A normal file search can find text. A graph can answer relationship questions. That matters because many AI coding mistakes are relationship m