The qu3-app is a comprehensive client-side application designed to facilitate secure interactions with Quantum-Safe Multi-Compute Provider (MCP) environments. It employs advanced post-quantum cryptography algorithms such as Kyber-768 for key encapsulation and SPHINCS+ for digital signatures to ensure data integrity, authentication, and confidentiality. The app manages cryptographic keys, establishes secure sessions through a KEM handshake, and encrypts requests and responses using AES-256-GCM. It also verifies server attestations and signs requests for client authentication. The system includes a mock server for testing, supporting functionalities like inference, policy updates, and key distribution in a quantum-resistant manner.