A balancing and control (B&C) system for API transactions is disclosed. The system may write a request confirmation and a request acknowledgement to a blockchain in response to an API request being transmitted from a consumer system to a provider system, with the request confirmation and the request acknowledgement each comprising a request hash of the API request. The system may also write a response confirmation and a response acknowledgement to the blockchain in response to an API response being transmitted from the provider system to the consumer system, with the response confirmation and the response acknowledgement each comprising a response hash of the API response. The blockchain may execute a smart contract to compare the request hashes from the request confirmation and the request acknowledgement and the response hashes from the response confirmation and the response acknowledgement to identify one or more out-of-balance events.