Mysten Labs Announces Verifiable Agent Arbiter in Collaboration with Google Cloud

Mysten Labs, in collaboration with Google Cloud, today announced Verifiable Agent Arbiter (VAA), an evidence layer being co-developed to enable enterprises to prove their AI agents acted within the authority they were granted. As agents move to executing transactions, negotiating with other agents, and acting across company boundaries, VAA gives enterprises a record of that activity that can be verified independently of the platform that produced it.

Today’s organizations want to move agents into production but are held back by the absence of a record that a counterparty, auditor, or regulator can trust. VAA is designed to provide that record and help companies comply with upcoming regulatory requirements, including the EU AI Act, which from 2027 will introduce penalties of up to €15 million or 3% of global annual turnover for logging failures.

VAA separates the record of an agent's activity from the proof of its integrity. Detailed telemetry, including prompts, model outputs, tool calls, and policy decisions, remains private in customer-controlled Google Cloud Storage. Cryptographic proofs of that record will be stored on Walrus, the data platform built for the demands of AI, and coordinated on Sui, a Layer 1 blockchain. 

Key Enterprise Capabilities

• Dispute replay across companies. When two organizations' agents transact through the open Agent2Agent (A2A) protocol, developed by Google Cloud and donated to the Linux Foundation,  both parties can replay a disputed workflow against the same verifiable receipts, establishing what was committed, what was delivered, and where it failed, in minutes rather than days spent reconciling conflicting logs.

• Incident reconstruction. Security teams can reconstruct the instructions, policies, decisions, outputs, and tool actions surrounding a suspected rogue execution, and distinguish a prompt-injection attack, a policy bypass, a model failure, and a post-incident change to the logs.

• Durable record retention. Archived evidence can be re-proven under future cryptographic standards, including post-quantum, without breaking its link to the original record.

• End-to-end agentic commerce. VAA connects directly with the Sui Agent Payments facilitator, which lets agents discover services and settle payments for API calls instantly using the x402 protocol. VAA cryptographically logs the underlying authorization, spend decisions, and service delivery.

"AI agents are starting to make decisions with financial and legal consequences, and we need systems to ensure they cannot exceed their authority. This requires evidence any counterparty can verify," said Evan Cheng, Co-Founder and CEO of Mysten Labs. "Verifiable Agent Arbiter brings together records of what an agent was permitted to do, what it did, and what resulted, and anchors proof to Sui and Walrus. We’ve engineered these networks to be neutral, resilient, and to hold up at the speed and scale of autonomous agents. With Google Cloud we are putting them to work inside enterprise workflows."

Initial deployments with enterprise customers are planned ahead of broader availability. For more information or to register interest, contact [email protected].