You asked about Security
49 people built something like it. 4 are gone.
That is 8% of the ones whose fate we could settle, against 23% across the whole register.
| Launched | What it was | Today |
|---|---|---|
| 2021-01-01 | YCCyble Cyble - World’s First Intelligence-Driven, AI-Native Security… · cyble.com | still up |
| 2017-01-01 | AI company transforming enterprise physical security to prevent… · ambient.ai | still up |
| 2021-06-01 | YCRootly AI-native on-call and incident response carefully crafted to help… · rootly.com | still up |
| 2022-01-01 | YCAgency Agency replaces traditional security and compliance headcount with AI. · getagency.com | still up |
| 2021-01-01 | YCauthzed Authorization Infrastructure securing AI at OpenAI, Zoom, & more · authzed.com | still up |
| 2022-01-01 | YCCinder Infrastructure to protect companies from AI abuse · cinder.ai | still up |
| 2017-06-01 | YCD-ID Enable creators and developers to generate realistic AI personas · d-id.com | still up |
| 2024-01-01 | Autonomous offensive and defensive cybersecurity platform · codeant.ai | still up |
| 2021-01-01 | AI-powered Compliance Platform for PCI 4, CCPA, HIPAA, CIPA, 50+ laws · feroot.com | still up |
| 2020-06-01 | YCSwif.ai Manage every device. Govern every AI agent. · swif.ai | still up |
| 2024-06-01 | Automate security and privacy reviews · clearly-ai.com | still up |
| 2021-06-01 | Security Delivery Platform to orchestrate AI agents for Service… · contraforce.com | still up |
| 2025-01-01 | YCConntour AI to monitor thousands of security cameras. · conntour.com | still up |
| 2023-01-01 | The Control Plane for Enterprise Agents · credal.ai | still up |
| 2023-01-01 | YCVariance AI Agents for Fraud Review and Investigations · variance.com | still up |
| 2020-01-01 | YCSkypher AI agent for Compliance Questionnaires Automation · skypher.co | still up |
| 2021-06-01 | AI-driven mobile cybersecurity · mallocprivacy.com | still up |
| 2021-06-01 | YCidemeum AI-powered Application Control · idemeum.com | still up |
| 2019-06-01 | YCTraces Transform your video monitoring with AI · traces.ai | still up |
| 2021-06-01 | Never code alone. · squire.ai | gone |
| 2022-01-01 | YCStrac Data Discovery, DLP, DSPM for SaaS, Cloud, Gen AI & Endpoints · strac.io | still up |
| 2024-06-01 | YCUnbound Use AI tools without fear of data leakage · getunbound.ai | still up |
| 2025-09-01 | Zero-trust authentication, authorization, and auditing for AI agents · multifactor.com | still up |
| 2020-01-01 | AI for security cameras · visualone.tech | gone |
| 2026-06-01 | AI cybersecurity for financial institutions' digital assets · verdictmachine.com | still up |
| 2021-06-01 | Web infra for AI agents · hyperbrowser.ai | still up |
| 2026-06-01 | Autonomous AI defense system for cyber attack · nebusec.ai | still up |
| 2025-06-01 | YCPangolin Open networking and security for your workforce, AI agents, and infra · pangolin.net | still up |
| 2025-06-01 | AI infrastructure for biosecurity · twentytwo.bio | still up |
| 2025-09-01 | Continuous AI pentesting that finds and fixes vulnerabilities · verialabs.com | still up |
| 2026-01-01 | Frontier AI Defenses for Social Engineering Attacks · beesafe.ai | still up |
| 2024-01-01 | YCRisotto Risotto auto-solves IT support requests using AI · tryrisotto.com | still up |
| 2023-01-01 | Detect every data leak into third-party GenAI tools · compliantllm.com | still up |
| 2026-01-01 | YCLexius AI for Corporate Security Cameras · lexius.ai | still up |
| 2026-06-01 | YCFabraix The world's frontier hacker of AI agents. · fabraix.com | still up |
| 2024-01-01 | Security for AI-native developers · superagent.sh | still up |
| 2024-01-01 | YCAedilic Open-Source AI-generated image/deepfake detection · nonescape.com | gone |
| 2024-09-01 | The AI Security Engineer to Find and Fix Vulnerabilities · gecko.security | still up |
| 2025-09-01 | The sensitive data redaction layer for AI · logosguard.com | still up |
| 2023-01-01 | YCBlyss End-to-end encrypted AI. · blyss.dev | gone |
| 2026-06-01 | YCDecawork Training company-specific models that approve AI actions. · decawork.ai | still up |
| 2026-01-01 | The control plane for AI agents. · agenticfabriq.com | still up |
| 2025-09-01 | AI Agents for Platform Engineering · usekestrel.ai | still up |
| 2026-06-01 | CrowdStrike for AI Agents · traceforce.ai | still up |
| 2024-06-01 | YCwinfunc ai-native security engineering for mission critical codebases · winfunc.com | still up |
| 2026-06-01 | YCPalisade AI that finds and fixes OS-level vulnerabilities across device fleets · palisade-ai.com | still up |
| 2024-01-01 | YCTracecat The open source AI-native security automation platform · tracecat.com | still up |
| 2026-06-01 | YCOneCLI The open source AI teammates for your company. · onecli.sh | still up |
| 2024-01-01 | LLM Security and Compliance · promptarmor.com | still up |
How this compares
The register re-probes every domain it holds. Some that answered last month stop answering. We send that list — what went quiet, and what it was — once a month. Nothing else.
How this was made. Show HN entries are every post from 2021 to 2023 with at least five points that linked to its own domain; code hosts and free hosting are excluded, because a repository outlives the effort behind it. Product Hunt entries needed 100 votes — a far higher bar, so they are the promoted top slice rather than a like-for-like sample. Both are judged by asking the domain whether it still answers: gone means it no longer resolves, refuses the connection, serves a parking page, or says plainly that it shut down. An HTTP error is not counted as gone — a server answering 404 is one somebody still pays for, and an audit of 25 gone-calls found two such sites alive with only a moved homepage. Y Combinator entries use the status YC publishes itself, which is why only those can say acquired. Squatted domains — a lapsed name now serving somebody else's site — are not detected, so these figures run slightly low.