Armorer Labs is for security and engineering leaders at regulated companies that build their own AI agents. It finds issues those agents can actually be pushed into, including prompt injection, goal hijacking, and data leaks, then prepares a fix the team can approve without stopping the work the agent is there to do. The company launched publicly in October 2026 from Y Combinator's Fall 2026 batch, as firms put agents on live files, tools, and keys, where a hidden instruction or a tampered tool result can move confidential data outside the company. The workflow has four parts. Armorer maps what an agent can reach, including tools, permissions, identities, and data. It simulates attacks and reports the ones that actually succeed. It writes the smallest change as a pull request or a runtime policy, and the customer's engineers approve it after Armorer shows the attack fails and the original workflow still completes. In production, Armorer Guard checks each action on CPU, with no GPU required, and allows, holds, or denies it. The company says a verified fix is ready for approval in about four hours, onboarding takes under 30 minutes, and the software can run in the customer's cloud or on-premises, including air-gapped environments. Findings are mapped to ISO/IEC 42001 and AIUC-1, so the same evidence can sit in a certification review. Co-founders Daniel Begimher and Cristian Leo spent years on AI security at AWS before starting the company. Begimher, CEO, led development of AWS Security Incident Response's first customer-facing investigative agent from early work through public launch. Leo, CTO, led AI security science at AWS and created ThreatForest, an open-source agent that builds attack trees from source code. Y Combinator partner Kulveer Taggar said the firm funded them in the F26 batch. Paul Vixie, inducted into the Internet Hall of Fame in 2014, is an advisor and investor.