
Real-world sandboxes to test agents and agent-facing software
We build environments to test your app and agents against the real world. Deploy your code/agent into a sandbox that runs against replicas of external services (Stripe, Slack, Google Drive, etc.). Twins support the same APIs, MCP tool calls & SDKs as the real software, and you can spin up thousands of instances in parallel and seed them using natural language. Run real workflows, surface edge cases, and observe how your code/agents actually behave before hitting production.
GPAgent keeps YC listings public and neutral. Fund-specific scoring, notes, and workflow state live in each customer workspace.
Join the GPAgent waitlist