What it sells
Block bots & bad behavior
Business model breakdown
Buyer: who owns the budget?
Security, risk and fraud leaders at consumer web/app companies (Atlassian, Canva, Framer, Lovable, DailyPay, Rakuten).
Trigger: what makes them buy now?
Fake accounts, account takeover, multi-accounting, SMS pumping, API abuse and content abuse.
Workflow: what inputs become what output?
Send device, email, IP and behavioral signals through Castle SDK/API, get risk scores and block or challenge abusive accounts.
Economics: what it saves and how it charges
Usage-based API pricing with included usage per plan, scaling linearly.
Distribution: how it reaches customers
Self-serve free tier plus contact sales for enterprise.
Funding history and coverage
| Round date | Stage | Amount | Investors | Source |
|---|---|---|---|---|
| — | Y Combinator Winter 2016 | — | Y Combinator | ycombinator.com |
Profiles summarize public reporting and company websites. Business-model notes are MaxBC's reading of that material, not confirmed facts; unknowns are left blank rather than guessed. Updated 2026-10-12.