The External Host Interface provides a facility to enable exchange of data between Thredd and external systems via our web services. All transaction data processed by Thredd is transferred to the External Host side via EHI in real time. For certain types of transactions, such as Authorisations, the External Host can participate in payment transaction authorisation. data feed and transaction XML reports. You can use the information in the XML reports to match and reconcile against data received via EHI, check for any duplicate records, and match authorisation records (e.g., authorisation advices and authorisation reversals) to financial records (e.g., presentments and chargebacks).