ChatCrystal
A local-first personal knowledge app for developers that imports past conversations from tools such as Claude Code, Cursor and Codex CLI, distills them into searchable notes with a tag knowledge graph, and exposes that knowledge to agents through MCP.
ChatCrystal imports AI coding conversations from the local data directories of tools such as Claude Code, Cursor, Codex CLI, Trae and GitHub Copilot, then distills each one into a structured note with a title, summary, conclusions, code snippets and tags. Notes can be searched semantically with embeddings and relation-aware result expansion, and a tag knowledge graph visualizes knowledge points as tags with edges weighted by how often they co-occur.
Its CLI and MCP interfaces let an agent recall and write back reusable experience from that knowledge base during a later coding session, and the app runs with configurable LLM and embedding providers, including a built-in OpenAI-compatible router. It is distributed as a desktop application, a CLI and web server, or a Docker Compose deployment for self-hosting across multiple devices.
It requires Node.js 24 or later, is written in TypeScript, and is licensed under Apache-2.0.