Humanloop
Humanloop is a platform for managing prompts, running experiments, and evaluating LLM outputs in production. It provides a prompt editor, version history, A/B testing across models, and human plus automated eval workflows — keeping your prompts in sync with your code.
Vellum
End-to-end platform for prompt engineering teams. Version prompts, run A/B tests, evaluate quality, and deploy to production with a visual interface.