# SecTransformSetAttribute(_:_:_:_:) Sets a static value for an attribute in a transform. ``` func SecTransformSetAttribute(_ transformRef: SecTransform, _ key: CFString, _ value: CFTypeRef, _ error: UnsafeMutablePointer?>?) -> Bool ``` ## Parameters `transformRef` The transform whose attribute is to be set. `key` The name of the attribute to be set. See [Transform Attributes](/documentation/Security/transform-attributes) for a list of valid keys and possible values. `value` The static value to set for the named attribute. `error` A pointer that the function uses to provide an error object with details if an error occurs. The caller becomes responsible for the object’s memory. Pass `NULL` to ignore the error. ## Return Value A Boolean set to if the call succeeds. Otherwise, the `error` parameter contains information about the failure. ## Discussion This function is useful for things like iteration counts and other non-changing values. It returns an error and the named attribute is not changed if [`SecTransformExecute(_:_:)`](/documentation/Security/SecTransformExecute(_:_:)) has already been called on the transform. Compare this function with the [`SecTransformConnectTransforms(_:_:_:_:_:_:)`](/documentation/Security/SecTransformConnectTransforms(_:_:_:_:_:_:)) function which sets derived data. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)