Upjack

Upjack is a framework for building AI-native applications by describing your data model and domain expertise, rather than writing backend code. You define entity schemas in JSON and domain rules in Markdown, then tell an AI agent what you want—it generates a complete MCP server with CRUD tools, validation, search, and storage, all automatically.

The maker says it was built with Claude Code. Built on FastAPI and MCP (Model Context Protocol), Upjack eliminates boilerplate by generating six tools per entity (create, read, update, delete, list, search), enforcing JSON Schema validation, providing full-text search, and storing data as git-friendly JSON files. Apps run locally in Claude Desktop, Claude Code, or any MCP client.