Boundary

BAML is a programming language for building AI agents, designed to address the reliability and observability challenges of code written largely by models. It combines TypeScript-like syntax with strict typing that rejects unchecked casts and `any`, alongside fast compilation and concurrency features. The language runs standalone on macOS, Linux, and Windows, or integrates into existing projects through bridges to Python, TypeScript, Node.js, Java, C#, C++, Go, Rust, Kotlin, Swift, and PHP.

Core capabilities include typed AI functions with schema-aligned parsing for structured model output, always-on tracing and profiling of every function, an agent-first toolchain with a fast compiler and CLI, workflow primitives such as concurrency, retries, cancellation, and sandboxing, and testing that grades distributions across many runs. BAML is open source under Apache-2 and runs entirely on your machine without calling external servers. A cloud offering covering observability, team controls, and governance is planned for later availability.