Review areas
Solutions
Six focused review areas, each scoped to how payment and transaction APIs actually get misused. Engagements can cover one area or all of them, depending on where a platform is in its lifecycle.
Authentication & session review
We examine how tokens are issued, refreshed, and revoked, and whether session boundaries hold up when a user tries to act outside their intended scope.
- Token expiry and refresh flow behavior
- Cross-account and cross-role access attempts
- Multi-factor and step-up authentication triggers
- Session invalidation after password or credential changes
Rate limiting & abuse controls
We map which endpoints enforce limits, how those limits are calculated, and whether they hold up against distributed or bursty request patterns.
- Per-account, per-key, and per-IP limiting behavior
- Retry and backoff handling under load
- Card testing and enumeration resistance
Data exposure & response filtering
Response payloads are reviewed field by field to see whether internal identifiers, partner data, or excess transaction detail is returned unnecessarily.
- Field-level review of response payloads
- Role-based response differences
- Error message and stack trace exposure
Token & key lifecycle assessment
API keys and secrets often outlive their purpose. We look at issuance, rotation, storage, and how a compromised key would actually be detected and revoked.
- Key rotation policy and enforcement
- Scope granularity per issued key
- Detection path for anomalous key usage
Logging, monitoring & alerting review
We assess whether the events that matter for a payment API are actually captured, retained, and connected to an alert someone will see in time.
- Coverage of authentication and authorization events
- Retention windows against investigation needs
- Alert thresholds for anomalous transaction patterns
Incident readiness tabletop exercises
A structured walkthrough of a hypothetical API incident, from first alert to containment, to see how the team would actually respond and where the process has gaps.
- Simulated incident timeline and decision points
- Communication path review
- Post-exercise gap summary
How an engagement gets scoped
Scope is set before any testing begins, based on a short technical questionnaire and, where useful, a walkthrough of the API documentation. This covers the number of services involved, the authentication models in use, and any parts of the system considered out of bounds for testing.
Engagements can focus narrowly on one review area, such as authentication alone, or span the full set. Smaller platforms with a single service often start with a combined authentication and data exposure review, then expand from there.
What the report looks like
Reports are organized by finding, not by tool output. Each entry includes what was tested, the observed behavior, why it matters specifically for payment or transaction data, and a suggested severity.
A short executive summary sits at the front for stakeholders who need the overall picture without reading every technical detail, while the appendix holds the request and response evidence for engineering teams doing the fix.
Not sure which review area applies to you?
Describe your API setup and we'll suggest where to start.
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