Prompt & Build

Prompt & Build develops open-source AI governance tools for developers running autonomous coding agents in production. The company builds GuardRail and the broader AgentStack suite — five tools covering pre-execution security, LLM routing, overnight code improvement, codebase knowledge graphs, and self-improving agent frameworks. Founded and operated by Frederik van der Heyden, the team runs 13 production applications with AI agents and zero dedicated ops staff, extracting guard patterns and governance frameworks from real incidents. Their work also includes a KI-Governance Masterclass and the book *Runs Without Me*.