# SelectRequest

The SelectRequest object is submitted as part of the Select request message (input).

Parameter | Type | Constraints | Description
--- | --- | --- | ---
TransactionData | sequence | Required | Transaction data in the form of a XML file, confirming to the ExpereTxn schema, used to process the request.
ContentIdentifier | string | Required | Defines the type of content to be used.
CallbackUri | string | Required | A string of characters used to identify a system resource. In this implementation, the value should reflect the fully qualified URL used as the recipient of a response (the callback URI) after the document has been generated. The callback is submitted without security parameters.
AccountId | string | Required | A unique identifier for the account associated with the request. This is assigned as part of an account's administration setup process.
ProductType | string | Required | The type of the product associated with the instance.
IdentityId | string | Required | An identifier for the entity associated with the generated documents submitted on the transaction data.
ExternalKey | string | Required | An identifier defined by the requesting application and passed as a string value. It is typically used to supply an identifier or reference value for a given request and is mapped to the RequestID.
RequestID | string | Required | A unique identifier for the submitted request. Often used for request tracking purposes.