> For the complete documentation index, see [llms.txt](https://docs.vida.id/identity-stack/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vida.id/identity-stack/verify/id-fraud-shield-sdk/signals-and-rules.md).

# Signals and Rules

Signals are raw data points collected from the device, session, network, and user behavior during each transaction. Unlike rules — which fire only when a specific fraud pattern is matched — signals are always returned in every API response, giving you a complete picture of the session context. You can use signals to build your own risk logic, enrich your internal fraud models, or audit specific sessions in detail.

**Note:** Signal availability depends on the SDK integration type. Some signals are only available via Mobile SDK (iOS/Android), others via Web SDK, and some from both.

Rules are **predefined fraud patterns** evaluated automatically by ID Fraud Shield on every session. When a session matches a rule's conditions, the rule is triggered and returns a **risk level** — which can be used for alerting, automated blocking, or manual review workflows.

For further info regarding signals and rules coverage, **please reach out to our Sales Team at <bd@vida.id>**.&#x20;