# Braintrust vs Arize Phoenix

Arize Phoenix is open source and Braintrust is not, so the question is whether you want source access and the option to fork, or would rather have a vendor accountable for it.

| | Braintrust | Arize Phoenix |
| --- | --- | --- |
| Licence | Proprietary | Open source |
| Pricing | freemium | open source |
| Self-hostable | Yes | Yes |
| Languages | Python, TypeScript | Python, TypeScript |
| Install | — | pip install arize-phoenix |
| Keys required | BRAINTRUST_API_KEY | None |

## Full pages

- https://newagent.build/c/braintrust
- https://newagent.build/c/phoenix

## Machine interfaces

- `GET https://newagent.build/api/registry` — every component as JSON
- `GET https://newagent.build/api/vendors` — vendors, with the repo and releases feed to watch
- `GET https://newagent.build/api/advise?q=<plain english>` — recommended stack for a description
- `GET https://newagent.build/api/stack?<layer>=<id>&format=sh|json|md|yml|agents|env` — a stack as files
- `GET https://newagent.build/llms.txt` — the whole registry in one fetch

Any page here also returns markdown if you send `Accept: text/markdown`.