Cosine is an AI knowledge engine specializing in understanding codebases within the software development industry. The company offers a tool that provides developers with answers to coding questions, explanations of code features, and suggestions for writing new code, all through a VS Code extension. Cosine's technology is designed to index and comprehend codebases on multiple levels, utilizing semantic search and other heuristics to deliver fully contextual answers and facilitate the planning and implementation of new features. Cosine was formerly known as Buildt.