Radix offers a few different APIs, for different use cases. Notably:
The Gateway API is exposed by the Network Gateway, and is a high-level API intended for use by Wallets and Explorers. It can be used for reading account balances, high-level transaction details, and efficient queries of historic ledger state, and can be used for transaction construction.
The Core API is one of the Node APIs and exposed by Radix Nodes. It is designed to run on a private network, and be used for low level access to the ledger state. It provides an optional transaction stream, and inefficient queries of current ledger state. It also provides transaction construction capabilities, and allows for signing messages with the node’s private key, where enabled. It does not expose the ability to efficiently query account balances.
You can interact with the APIs using clients generated against the Open API specifications, or can use any tool, framework, or language as long as it supports the HTTP protocol.