PromptLayer

PromptLayer provides an infrastructure layer for managing, evaluating, and monitoring large language model applications. It operates as a proxy that intercepts and logs all LLM API calls, capturing requests, responses, and associated metadata. This mechanism enables a central Prompt Registry where prompts can be versioned, organized, and deployed without altering application code. Core capabilities include a no-code prompt editor for collaborative editing, historical backtests against previous inputs, and functions for running regression tests to ensure consistent performance. The platform is designed for AI engineering teams, ML developers, and prompt engineers building production-grade systems. A primary workflow involves A/B testing a new prompt variant against a control version to validate performance before deployment. Teams also use it to run regression tests on curated evaluation sets, preventing performance degradation after a model or prompt update. For debugging, developers can use the observability traces to jump from a bug report directly to the specific failed LLM interaction.