Sepal AI
The business, the turning points, and the decisions behind them.
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Sections to complete：02 · 05
01 / WHAT IT BUILT
What the company did
Sepal AI was a San Francisco AI data startup founded in 2024 and a member of Y Combinator's Summer 2024 batch. With a team of 15, it did data development for advanced AI — building reinforcement-learning training environments in which AI agents could interact with realistic simulated software, make mistakes and learn, all without touching live systems. Its work sat at the bottleneck of agentic AI training: runnable environments that teach models to perform tasks inside enterprise software.
02 / FAILURE REASONS
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03 / EVENT HISTORY
Events in the structured record
- Founded
Sepal AI is founded in San Francisco and joins Y Combinator's Summer 2024 batch, building RL training environments and data development for advanced AI.
- Acquired by Mercor
In February 2026, Mercor — the AI talent and training-data company with over $2 billion in annualized revenue — acquires Sepal AI as part of a deliberate strategy to roll up specialized AI training tools; Y Combinator marks Sepal AI's status as Acquired.
04 / CONTEMPORARY REBUILD ASSESSMENT
Difficulty of rebuilding this project today
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Overall assessment: Not completed
05 / CAUSAL CHAIN / AFTERMATH
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