Boundary

Boundary builds BAML, a programming language for developers building AI applications and agents. Developers declare model calls as typed functions, specifying inputs and expected outputs, with tools for streaming, testing, tracing, and coordinating concurrent work. BAML can run independently or within existing applications: generated typed language bindings let developers call BAML functions from eight languages, including Python, TypeScript, Go, and Swift, without rewriting their codebase.

Founded in 2023, Boundary is led by co-founders Vaibhav Gupta, CEO, and Aaron Villalpando, CTO. Gupta previously worked on Google’s Pixel 4 and Microsoft’s HoloLens; Villalpando built monitoring and streaming systems at Amazon. BAML’s technical approach includes schema-aligned parsing, which repairs malformed model output against declared types. Its language bridges combine a shared native interface with generated typed interfaces, connecting BAML functions to code in other languages.

BAML is free, Apache-2 licensed, and works offline. Boundary’s commercial offering is Boundary Web Services, with observability offered through early access. In its recap of 2024, the company reported growth from 10 to more than 1,000 active developers.