Credential stuffing defense for login APIs
How velocity, bot-like clients, and breach-aware signals help stop stuffing without locking out real users.
By AbuseGraph Team
Stuffing looks like many correct attempts
Credential stuffing replays leaked username/password pairs. Rate limits help, but sophisticated clients rotate IPs and mimic browsers. You need risk context, not only a 429.
Layered defense
- Edge / bot challenges for obviously automated traffic
- Account risk check on sign-in with velocity and client signals
- Step-up (MFA) when the verdict is uncertain
- Exposure monitoring after accounts exist — so you learn when credentials appear in new dumps
Why check-based metering helps
Stuffing spikes create traffic. MAU-only pricing can punish growth; opaque enterprise pricing delays rollout. AbuseGraph Free (1,000 live checks) and published Pro/Scale overages make it easier to put checks on the hot path.
Do not confuse CAPTCHA with account risk
Challenges stop some bots. They do not explain why a login looks like takeover, and they do not build a multi-account graph. Use both when you need both.
Further reading
Next
Put a live check on signup
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