Addressing the Lack of Business Issue Reporting in BAP to BPP Communication

[emmayank]

Problem Description
The current communication flow between BAP and BPP lacks a mechanism for reporting business issues back to BPP. When a BAP receive /on_action call, the process involves protocol-level checks, business-level processing, and communication through next /action endpoint. However, when BAP encounters a business issue within the payload during the processing stage, there is no established way to convey this error back to BPP.

Current Flow

1. BAP Initiates /action Call to BPP
2. BPP perform protocol level check and send ACK synchronously
3. BPP perform Business level check and processing and call /on_action
4. BAP perform protocol level check and send ACK synchronously
5. BAP perform Business Level Check and Processing and identifies a business-level issue within the payload.
6. Currently, there is no established way for BAP to convey the encountered error back to BPP.

Examples of Business Issues

1. Incorrect Quote in on_select:
   If BPP sends a wrong quote in on_select, BAP acknowledges it at the protocol level but cannot proceed with the transaction due to the incorrect payload.

2. item_id getting changed in on_action:
   If BPP sends a different item_id in on_action, BAP acknowledges it at the protocol level but faces difficulties in processing the transaction.

@92shreyansh and @tanyamadaan Please review the outlined communication flow and gap. Feel free to add any additional points or considerations.

@ravi-prakash-v Your input on potential solutions to address this problem would be valuable. How can we establish a mechanism for BAP to report business-level issues back to BPP?

Next Steps
Let's collaboratively discuss and brainstorm potential solutions to address the lack of business issue reporting in the current communication flow. Feel free to suggest improvements, alternative approaches, or any additional considerations.

Please contribute to the discussion, and let's work towards enhancing the robustness of the communication process between BAP and BPP.