Fabraix
Fabraix is an artificial intelligence company in San Francisco, United States, founded in 2026. It has raised $500K across 1 round, most recently a $500K Pre-Seed in June 2026.
Find vulnerabilities in your AI systems before users do.
- Headquarters
- San Francisco, California
- Employees
- 1–10
- Founded
- 2026
- Business Model
- B2B
- Website
- fabraix.com
- Total Funding
- $500K
- Last Round
- $500K Pre-SeedJun 2026
- Rounds
- 1
Totals include recorded grants and other qualifying funding, not just equity. What counts toward funding.
Indexed holds 1 funding round and 2 investors for this company. The full record is or through the API.
About
Fabraix is a Y Combinator-backed (S26) AI security research lab that builds autonomous red-teaming agents to continuously find vulnerabilities in customer-facing AI systems. Its flagship product, Nyx, probes AI agents in pure blackbox mode — no source code access required — using a library of over 10,000 adaptive attack strategies that dynamically adjust based on the target agent's defenses, covering security, logic, and alignment failures across chat, voice, browser, and coding agents. Fabraix has achieved a 78% attack success rate on the AgentHarm benchmark (vs. 67% for GPT-5.6 Sol) and has already surfaced exploitable vulnerabilities in AI agents at dozens of Fortune 500 companies.
Summary
It lists 1–10 employees. It has raised $500K in total across 1 round, most recently a $500K Pre-Seed round in Jun 2026. Investors include Y Combinator and Byld Ventures.
Funding History
Jun 2026
Investors
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