AI agents now issue refunds and move money, but top models get irreversible actions right only about 56% of the time. Worlds lets you test your agent locally in exact replicas of Stripe, Zendesk, and Salesforce. Describe a scenario in plain English, inject failures like an expired API key, and fast-forward time to catch delayed mistakes. Every run is graded on real state, is deterministic, and fits your CI/CD: one command, no SDK, free today. Feel free to find us here: usesparta.co

Hey everyone 👋 Arya here. I left Berkeley to build Worlds. We kept seeing the same thing with AI agents. They're great at talking, but the moment one needs to issue a refund or cancel an order, everyone gets nervous and it ships read only. Fair enough, since top models get those actions right only about 56% of the time. Worlds lets you test your agent in exact replicas of the tools it touches, then checks what actually changed, not just what the agent said it did. We have 97 worlds ready today, including Stripe, Zendesk, Salesforce, and Workday. Need one we don't have? Drop it in the comments, and we'll build it within 72 hours. And if you give Worlds a try, we'd love to say thanks with a donation to your favorite nonprofit. Just tell us which one 💙 I'll be here all day replying to everyone!

Sparta

The frontier of agent verification. Prove what changed.

The frontier of agent verification. Prove what changed.