The deciding difference is operational: Braintrust can run on infrastructure you control, Pydantic Logfire cannot. If that constraint is real for you, it settles the choice before anything else is considered.
Eval-first platform — scorers, datasets and a playground for prompt iteration.
OpenTelemetry observability with first-class Python and Pydantic AI support.
| Braintrust | Pydantic Logfire | |
|---|---|---|
| Licence | Proprietary | Open source |
| Pricing | freemium | freemium |
| Self-hostable | Yes | No |
| Languages | Python, TypeScript | Python, TypeScript |
| Install | — | pip install logfire |
| Keys required | BRAINTRUST_API_KEY | LOGFIRE_TOKEN |
The deciding difference is operational: Braintrust can run on infrastructure you control, Pydantic Logfire cannot. If that constraint is real for you, it settles the choice before anything else is considered. Braintrust: Eval-first platform — scorers, datasets and a playground for prompt iteration. Pydantic Logfire: OpenTelemetry observability with first-class Python and Pydantic AI support.
Braintrust can run on your own infrastructure. Pydantic Logfire is a hosted service only.
Braintrust is proprietary (freemium). Pydantic Logfire is open source (freemium).
Every page here answers to Accept: text/markdown and returns the same content at roughly a tenth the tokens. No separate site, no toggle — same URL.
curl -s -H "Accept: text/markdown" https://newagent.build/compare/braintrust-vs-logfire