NexArt is an AI evidence layer that turns any AI execution into a Certified Execution Record: a tamper-evident, cryptographically signed artifact capturing the inputs, parameters, outputs, and execution context of an AI decision. Engineers integrate it via a single SDK call without replacing existing infrastructure, and sensitive data can remain private through cryptographic commitments. The attestation node signs each record so that auditors, regulators, customers, or courts can independently verify its integrity without relying on internal logs or a live NexArt service. NexArt is designed for regulated industries and compliance teams that need portable, defensible proof of AI decisions for audits, disputes, and incident investigations.