Free & open — a public good
SybilShield is a free public good, not a product. No prices, no plans, no checkout. Anyone can use the sandbox and the public methodology at no cost — fair-use limits keep the shared service healthy.
Public sandbox
Register with an email, get an API key, and score address cohorts with the full evidence pipeline. No card, ever.
- · Full DROP / REVIEW / KEEP decisions + evidence reports
- · All six detection methods · public appeal flow
- · CSV export · dashboard polling and reads are free
// no card · email only
Fair-use limits
Sensible caps that keep the shared sandbox healthy for everyone — not a paywall. Doing heavy research? Email us and we'll help.
- · 100 calls / month (writes; reads are free)
- · Up to 1,000 addresses per analysis
- · 1 analysis at a time · 1 MB CSV upload
Open methodology
Any project can call GET /v1/score/:address for free at low volume — no registration required for read-only lookups on cached scores.
All six detection methods, the audit-log schema, and the appeal protocol spec are MIT-licensed. You can fork, self-host, or just borrow the methodology.
How this is funded
Grants, not customers
SybilShield is sustained by public-goods funding — ecosystem grants such as the Ethereum Foundation ESP, Gitcoin, Octant, Optimism RetroPGF, and Arbitrum — plus the open-source community. Sybil resistance is shared infrastructure, so we fund it the way other shared infrastructure is funded.
Why free?
A Sybil-detection tool that airdrop teams, DAOs, and grant committees can all trust works best when it's open and neutral. Charging per analysis would gate the exact teams who most need honest scoring. So it's free, the methodology is public, and the code is MIT-licensed.
Want to support it?
Fund a grant, contribute on GitHub, or send feedback that improves the models. Reach us at support@sybilshield.org.