Agnos APIs are made of a set of abstraction levels provided to integrators to develop their applications should it be a payment application, a transit application, a cash withdrawal application, a vending machine application, a test application, … This level of applications is called L3.
L2 API has not been standardized by EMVCo and payment stakeholders. Hence, there are different ways to interact with a L2 stack from a L3 stand point. All L2 stacks provides its own advantages and drawbacks. Normalization and complexity have been the 2 criterias considered to develop Agnos API.
We list different levels of abstraction to integrate with Amadis' L2:
Rich API: this is a legacy API provided a low granularity
OLA: this is a normnalized API provided for payment applications that fit into NexoFast’s model
Callbacks: this is a normalized API provided to better control the card processing flow
Exit conditions: this is a normalized API provided to better control the card processing flow without the drawbacks of using calllbacks
See Developer's guide.