Playgent

Playgent is a Y Combinator-backed company that sandboxes for AI agents. Based in San Francisco, USA, the company participated in the Summer 2025 batch of Y Combinator.

When enterprise agents fail in production, the conditions that caused the failure are critical: user state, data, tool calls, and context. Without a way to recreate these conditions, teams can't fix what broke.

Playgent provides infrastructure to create high-fidelity sandbox environments for AI agents. Our environments come packaged as a single MCP url where tool calls are mocked, authentication is abstracted away, and test data can be initialized via natural language or JSON specifications.

Playgent was part of Y Combinator's Summer 2025 cohort, has a team of approximately 2 employees, and is actively operating.