A system and method may simplify API design maintenance by providing an interface for configuring cryptographic parameters in the development of secure APIs to allow configuring MLE and X-Pay parameters, testing MLE and X-Pay-supported APIs, and directly viewing decrypted output of APIs which requires MLE. Rather than a pre-configured key store or creating a key store for each API, the system may refer to stored credentials and certificates to make, Mutual SSL and X-Pay token calls within the developer playground and create the key store programmatically. The configuration may be saved in a JSON format so that it may be reused at a later stage for retesting and also may allow saving the complete configuration including credentials, end point, request and response payload so that there is no need to update credentials in a centralized place. The solutions described herein may also eliminate sharing the private key over a network.