The 3-File Context Kit: Everything Your AI Needs to Understand Your Project

Every time you start a new AI coding session, you re-explain your project. The stack, the conventions, the folder structure, the gotchas. It takes 10 minutes. Every. Single. Time. Here's how I fixed it with three files that take 15 minutes to set up once. The Problem AI assistants have no memory between sessions. Each conversation starts from zero. So you either: Dump your entire codebase (wasteful, confusing) Re-explain everything each time (tedious, inconsistent) Just wing it and hope for the best (chaotic) None of these work well. Option 3 is why your AI keeps suggesting Express when you use Fastify. The 3-File Kit File 1: PROJECT.md — The Identity Card This tells the AI what your project is. Keep it under 50 lines. # Project: invoice-api ## Stack - Runtime: Node.js 22 + TypeScript 5.4 - Framework: Fastify - Database: PostgreSQL 16 via Drizzle ORM - Auth: JWT (access + refresh tokens) - Testing: Vitest ## Structure src/ routes/ # Fastify route handlers services/ # Business logic db/