- Bureau of the Fiscal Service
- Central Accounting Reporting System
- Reference and Guidance
- Application Program Interface (API) 

## Application Program Interface (API) 

Fiscal Service plans to replace the current bulk transaction upload process in the Classification Transactions and Accountability (CTA) module with an Application Program Interface (API).  An API is a connection between two computers, computer systems, or computer programs.  As part of the process, Fiscal Service will develop an API specification for distribution to entity partners.  This specification will outline how to establish a connection with the new API and what specific data elements will be needed to support the new reclassification process.

## API Requirements

The new API for CARS reclassifications is intended to support agencies with high volume of source and reclassification transactions, offering a system-to-system interface to allow agencies to automate their reclassification process.  Only one connection will be needed to support bulk transaction upload.  Both TanC and Reclassification transaction will be processed through the same interface.  

Soon, Fiscal Service will be releasing a connection guide on how to set up and interact with the Reclass and TanC API.  Refer to the CARS Reclass Modernization project website Key Target Dates for updates when the guide will be available.  There will be separate message types needed to support each transaction type.  

## Subject to Change:

*The data elements for the API are subject to change as result of development work and change in requirements.  Fiscal Service has not begun the development for the new API for CARS reclassifications and TanC activity, so changes most likely will occur.  Fiscal Service wanted to share with the CARS reclassification users what is documented to provide some insight about what the API will most likely look like and allow users to provide feedback.*

## Data elements needed to support TanC include the following:

Note 1: Please contact Fiscal Service for the “TanC Unique Code” mapping to group, scenario, and description information for your ALC.

Note 2:  Several “from” and “to” TAS/BETC entries can be sent in the same transaction message.

Sample TanC entries can be provided on request.

For Reclassification entries, the follow data elements must be sent:

## Data elements needed to support Reclassifications include the following:

## Important Note on Reclassification APIs:

Please note that for Reclassification API transmission, Fiscal Service is asking agencies to submit back to CARS the Business Event Control Number and GWA Rec number of the source transactions that need to be reclassified.  These data elements can be found on the CARS Account Statement download.  Rather than using the Business Event Control Number/GWA Rec number, agencies may submit a document number or schedule number of the CARS source system transaction they wish to reclassify.  Although using document number or schedule number is acceptable, using the Business Event Control Number and GWA Rec number combination will help Fiscal Service ensure proper traceability back to the originating source transactions and maintain controls for auditability.  The data integrity of document and schedules numbers are not as consistent and may cause reconciliation issues.  

Last modified 02/10/23