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Velocity Checks
SiftlyAPI monitors signup frequency in real-time to detect bulk registration attempts and abuse patterns from the same source.
What Triggers Velocity Flags
Rapid IP Signups
Multiple signups from the same IP address in a short period indicate automated registration
Domain Burst
Sudden spike in signups using the same email domain can indicate a coordinated attack
Pattern Escalation
Risk increases as signup frequency rises — moderate volume gets flagged, high volume is blocked
Cross-Signal Correlation
Velocity signals are combined with Email Intelligence, Network Analysis, and Device Fingerprint data for higher accuracy
Velocity Risk Levels
| Pattern | Risk | What It Means |
|---|---|---|
| Normal signup rate | Low | Natural user registration — no concern |
| Elevated frequency | Medium | Unusual pattern — may require verification |
| Bulk registration | High | Strong indicator of automated abuse |
Handling Velocity Flags
When a signup is flagged for elevated velocity, consider requiring email verification or CAPTCHA rather than outright blocking — it may be a legitimate user behind a shared IP (e.g., office or university).