Raindrop Simulations promises to build agent test environments for every pull request

Raindrop Simulations automatically creates simulated worlds to test agents on every pull request, according to a post describing the tool. The author claims its mocked services and databases enable replaying thousands of historical traces on a completely new harness—the setup that runs the agent. In a follow-up, they call simulations the most effective way they've seen to test agent changes before production, but say making those tests survive harness changes, such as adding a tool, is especially difficult.