What is Braintrust used for?

Braintrust is an evaluation and observability platform for AI applications that traces production agents, runs evals and catches regressions before release. It is a good fit for catching regressions before deployment, debugging production agent behavior and turning production failures into test cases.

Yes. Braintrust has a free plan, and paid plans start at $249 per month.

Is Braintrust open source?

No. Braintrust is proprietary (closed-source) software. Open-source alternatives to Braintrust include Opik, Arize Phoenix and Langfuse.

What are some alternatives to Braintrust?

Braintrust competes with LangSmith, Arize AI and Galileo. For open-source options, see Enlisted's ranked list of open-source Braintrust alternatives.

Braintrust: features, pricing and alternatives

About Braintrust

Braintrust is a platform for measuring and improving the quality of AI applications and agents. It combines production observability with evaluation, so teams can see what their agents did, score the results and prevent regressions from reaching users.

The product is organized into Observe, Evaluate and Discover. Observe lets teams inspect prompts, responses and tool calls in real time and search large volumes of logs while tracking latency, cost and quality. Evaluate scores outputs using language models, code or human reviewers and can block bad releases. Discover surfaces patterns and behaviors in production that can be turned into new evals. The site also provides an eval library, workshops and an encyclopedia of eval concepts.

Braintrust is a proprietary commercial service with a published pricing page, sign-up and a contact-sales route. It is positioned for whole teams, from engineering to product, working on production AI.

Key features

Real-time inspection of agent traces
Evals scored by LLMs, code or humans
Regression checks that block bad releases
Search across large log volumes
Pattern discovery in production behavior
Eval library and learning resources

Good fit for

→Catching regressions before deployment
→Debugging production agent behavior
→Turning production failures into test cases

Tags: llm-evaluation; llm-observability; tracing; evals; agents; llmops; regression-testing; ai-infrastructure

Braintrust: questions and answers

What is Braintrust used for?: Braintrust is an evaluation and observability platform for AI applications that traces production agents, runs evals and catches regressions before release. It is a good fit for catching regressions before deployment, debugging production agent behavior and turning production failures into test cases.
Is Braintrust free?: Yes. Braintrust has a free plan, and paid plans start at $249 per month.
Is Braintrust open source?: No. Braintrust is proprietary (closed-source) software. Open-source alternatives to Braintrust include Opik, Arize Phoenix and Langfuse.
What are some alternatives to Braintrust?: Braintrust competes with LangSmith, Arize AI and Galileo. For open-source options, see Enlisted's ranked list of open-source Braintrust alternatives.