Weft is a programming language purpose-built for AI systems. It provides first-class primitives for calling LLMs, coordinating agents, integrating humans into workflows, and wiring together APIs and infrastructure. The language includes a durable executor with pause-and-resume capabilities, a visual graph representation of programs, and type-safe connections between nodes. Its node catalog supports LLM calls, code execution, communication, flow control, storage, and triggers, with the long-term goal of letting projects define their own nodes in the language itself.