0.security is launching 0cloud, a hosted service that tests pull requests before code ships. Developer teams connect a GitHub repository, and deterministic scanning plus AI agents run targeted tests in an isolated sandbox, then post evidence and a one-click fix on that same pull request. A cyber intelligence check also matches newly disclosed vulnerabilities and known exploits against the codebase, so the fix arrives inside the workflow the team already uses. The hosted product runs on an open-source security harness with a web console, a CLI, and an MCP server. The company uses that harness for authorized testing from web apps and dependencies down to binaries and the Linux kernel. It reports more than 30 merged Linux kernel zero-days, and its Y Combinator profile says the team has found and fixed dozens of previously unknown vulnerabilities in government software across multiple countries and in software running on more than 3 billion devices. Current work includes EY, leading tech companies, and defense organizations. The harness is free to run locally with your own model provider. 0cloud is the managed service, with a free start, no per-seat fee, and pull request security tests at $5 each. Co-founders Doruk Tan Öztürk and Fabian Zbinden started the company in Zurich and are in Y Combinator’s Fall 2026 batch in San Francisco. Öztürk, the CEO, previously worked as a cyber defense engineer at the largest Swiss conglomerate retailer. This launch puts a managed version of that research in front of any team that can connect a repository.