The model runs inside Intel TDX with NVIDIA confidential GPUs on NEAR AI Cloud, and signs each reply with a key that never leaves the enclave. The app checks that signature against the model's attestation report before it charges the pet, and the charge carries the hash of the signed text as its receipt. A reply it can't verify is free and marked unproven. Each brain size's prompt and model are stored on the contract, and Mochi's diary is published to NEARFS with its fingerprint (the memory root) kept on chain.