Braintrust

Braintrust lets engineering teams log and trace LLM calls with latency, token, and cost metrics, run structured evals against datasets to score output quality, and replay production traces against new prompts or models to catch regressions before shipping. It includes a playground for side-by-side comparison of prompts and models, supporting continuous quality measurement rather than one-off checks. This is the AI eval company at braintrust.dev, not the Web3 talent marketplace of the same name.