Langfa.st

Langfa.st helps AI teams develop and test prompts faster with structured evaluation and version control. It solves the core problem of unreliable and unscalable prompt iteration by offering collaborative tools for testing, regression detection, and performance tracking. Built using TypeScript, Python, and OpenAI's API, Langfa.st supports JSON/HTML schema validation, diff-based comparisons, and cost analytics. Ideal for teams shipping AI features into production.