Braintrust — AI for Software Development

Braintrust is for teams shipping LLM features who want one place for tracing, evals and prompt iteration. Observe lets you inspect prompts, responses and tool calls, search logs and track latency, cost and quality. Evaluate runs experiments against versioned datasets, compares prompts and models side by side, and scores with LLMs, code or humans. A trace can be added to a dataset in one click, so a production failure becomes a regression test. Patterns automatically surfaces recurring issues across traces, and Loop is an agent that generates better prompts, scorers and datasets. The platform is framework agnostic, with native SDKs for Python, TypeScript, Go, Ruby and C#, an MCP server for coding agents, and docs listing 90 integrations such as OpenAI, Anthropic, LangChain, LlamaIndex, CrewAI and OpenTelemetry. Pricing is usage based. Starter is $0 a month with 1 GB of processed data, 10k scores and 14-day retention, and Pro is $249 a month with 5 GB, 50k scores and 30-day retention. Overage is billed per GB and per 1,000 scores, so heavy tracing adds cost. Longer retention, SAML SSO, custom RBAC and an uptime SLA are not in Starter or Pro.