BrainTrust

Braintrust is an end-to-end platform for evaluating, testing, and improving LLM applications. It helps teams move from vibes-based prompt tuning to data-driven iteration with systematic evaluation, scoring, and regression detection.

Key use cases include:

• LLM evaluation — systematically score outputs with custom and built-in metrics
• A/B comparisons — compare different prompts, models, and pipeline configurations side by side
• Dataset management — build and maintain golden test sets for regression testing
• Human review — annotation workflows for labeling and scoring LLM outputs
• Prompt playground — iterate on prompts with instant evaluation feedback
• CI/CD integration — run evaluations automatically in your deployment pipeline

Braintrust is used by product and engineering teams who need to ship LLM features with confidence — knowing that changes improve quality and do not cause regressions. It bridges the gap between prototype and production by providing a systematic evaluation workflow.

The platform includes Braintrust AI Proxy, a unified API gateway with caching, logging, and fallback support.

1. Sign up at braintrust.dev and create a project.
2. Install the SDK:

   pip install braintrust

3. Run your first evaluation:

   from braintrust import Eval
   
   async def task(input):
       # Your LLM call here
       return output
   
   Eval('my-project',
       data=[{'input': 'question', 'expected': 'answer'}],
       task=task,
       scores=[Levenshtein]
   )

4. View results in the Braintrust dashboard with detailed comparisons and drill-downs.

Pricing: Free tier for individual use. Team plans starting at $25/user/month. See braintrust.dev/pricing.