16.4 API and Backend Security

When integrating FreCx into applications, backend systems act as intermediaries between users and the blockchain.

These systems must be designed to:

• securely manage private keys

• validate all incoming requests

• prevent unauthorized transaction execution

APIs should implement authentication and authorization mechanisms to ensure that only valid users can initiate actions. Rate limiting should be applied to prevent abuse, and all requests should be logged for audit purposes.

Sensitive operations, such as transaction signing, should never be exposed directly to client applications.