Key Highlights
- Mysten Labs and Google Cloud announced the Verifiable Agent Arbiter (VAA) as an evidence layer for AI agent activity.
- VAA creates independently verifiable records covering prompts, model outputs, tool calls, and policy decisions.
- Detailed telemetry remains in customer-controlled Google Cloud Storage, while cryptographic proofs are stored on Walrus and coordinated on Sui.
Mysten Labs, working with Google Cloud, announced Verifiable Agent Arbiter (VAA) on Tuesday. The evidence layer is designed so that cryptographic proofs of AI agent activity are stored on Walrus and coordinated on the Sui blockchain, while detailed records remain under customer control.
According to the official announcement, VAA produces records of agent activity that can be verified independently of the platform that generated them. Organizations seeking to place agents into production currently lack records that counterparties, auditors, or regulators can rely on. VAA is intended to supply those records and support compliance with requirements such as the EU AI Act.
Structure of evidence layer and listed capabilities
The announcement further notes that VAA keeps the detailed record of an agent’s activity separate from the cryptographic proof of that record’s integrity. Telemetry data, including prompts, model outputs, tool calls, and policy decisions, remains in customer-controlled Google Cloud Storage. Cryptographic proofs of the record are stored on Walrus, a data platform, and coordinated on the Sui Layer 1 blockchain.
When agents from different organizations transact under the Agent2Agent (A2A) protocol, which Google Cloud developed and donated to the Linux Foundation, both parties can replay a disputed workflow against the same verifiable receipts. The process is intended to establish what was committed, what was delivered, and where a failure occurred. Security teams can reconstruct the instructions, policies, decisions, outputs, and tool actions linked to a suspected unauthorized execution.
The reconstruction is designed to distinguish among prompt-injection attacks, policy bypasses, model failures, and post-incident alterations to logs. Archived evidence can be re-proven under future cryptographic standards, including post-quantum methods, while retaining its connection to the original record.
VAA links to the Sui Agent Payments facilitator, which enables agents to discover services and settle payments for API calls under the x402 protocol. The system records the underlying authorization, spending decisions, and service delivery.
Related developments on AI agents
On September 29, blockchain security firm Blockaid published a blog post addressing risks associated with AI trading agents. The firm stated that malicious instructions can be embedded in token names, symbols, and descriptions. If an AI system treats that text as an instruction rather than untrusted data, it may generate an unintended transaction. The risk increases when the agent is connected to a wallet or has authority to execute transactions.
In a September 2026 whitepaper titled The Machine-Native Economy, BlackRock’s Digital Assets Research group examined the intersection of artificial intelligence and digital assets. The paper, authored by Will Su, Robert Mitchnick, Jay Jacobs, and William Helm, describes AI systems as machine-native intelligence and crypto assets as machine-native money.
It states that as AI systems become capable of multistep tasks with limited human oversight, they will require native payment methods, and that traditional payment infrastructure is not well suited to that requirement.
Meanwhile, Binance published a leadership blog stating that centralized trading platforms will need to serve software agents in the same manner they currently serve human customers. The post references a developer layer the company introduced earlier in the year.
No further technical specifications, deployment timelines, or commercial terms for VAA were included in the Mysten Labs and Google Cloud statement.
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