# SDK Feature Decision Engine

## Process multiple decisions

 - [POST /zephr/decide](https://developer.zuora.com/zephr-api-reference/zephr-public-api/sdk-feature-decision-engine/processmultipledecisions.md): Processes multiple decisions. The SDK Feature Decision Engine can be invoked via the Public API to calculate a decision output response based upon Feature SDK Rules created in the Zephr Console.

## Process a single decision

 - [POST /zephr/decision-engine](https://developer.zuora.com/zephr-api-reference/zephr-public-api/sdk-feature-decision-engine/processsingledecision.md): Processes a single SDK feature decision. An SDK feature rule can be configured in the console, and allows a custom decision to be made using a range of inputs to drive the behaviour of a website or app. SDK features can output any one of several data types as configured in the console.
  - String: The output can be any string.
  - Number: The output can be any numerical value
  - Enum: The output can be one of a list of strings as configured in the developer panel for the rule. This is used for short output strings.
  - Component: The output can be one of a list of strings as configured in the developer panel for the rule. This is used for long output strings, such as HTML or JSON.
  - JSON: The output can be any JSON object. JSON schema validation can optionally be enforced when creating JSON outputs in the console.
  - Transformation: The output will be a JSON array of transformations to be applied to content on a webpage or in an app. This allows the configuration of the same types of outcomes that can be built with an HTML feature rule, such as hiding content and displaying a payment form.


SDK features permit business decisions to drive access or behaviour to be made in an app that is not using HTML content. SDK decisions are relevant for both anonymous and authenticated sessions. If no session is provided via the request then an anonymous session will not be created.

Invoking an SDK decision may cause side effects as configured in the rule, such as invoking webhooks or recording trial usages. When dryRunMode is enabled in the request, trial usages will not be recorded.

## Retrieve a single decision

 - [GET /zephr/decision-engine](https://developer.zuora.com/zephr-api-reference/zephr-public-api/sdk-feature-decision-engine/getsingledecision.md): For compatibility with CDN, any web headers (Referrer, User-Agent) will be accepted and passed onto the rule engine