Kristina King
Today, Proof put verified legal identity and transaction authorization for AI agents into production with the launch of x401, an open protocol that lets any website ask an AI agent to prove who it’s acting for and what that person approved. Proof works with Meta’s Muse, ChatGPT dots, Grok, Claude and other assistants that support the Model Context Protocol (MCP).
The launch comes weeks after Amazon blocked Muse from its marketplace, exposing a problem every business on the agentic web now faces: There is no reliable way to know who an AI agent is acting on behalf of, or whether that person authorized what it is doing. It also follows September guidance from FinCEN and federal banking regulators recognizing digital certificates and verifiable credentials, under certain conditions, as a permissible way for banks to verify customer identity.
With Proof, a consumer can authorize a wire transfer, approve an itemized purchase or sign a payment mandate through an AI agent. At the center of the launch is Proof’s agent identity wallet. It holds a person’s verified legal identity and lets them approve, on their own device, exactly what their AI agent can do. The agent carries the request; the person’s wallet signs it.The business receiving the request can independently confirm the consumer’s verified legal identity and check the cryptographic signature on the transaction itself. If the agent changes the amount, recipient or other signed terms, the signature no longer validates.
Three capabilities are live today:
– Proof’s agent identity wallet, which shows the information and transaction terms being requested
– x401, an open HTTP protocol for requesting and verifying that evidence
– A production Model Context Protocol (MCP) server that works with AI assistants, including Meta’s Muse, ChatGPT dots, Grok and Claude.
Websites can request verified identity claims without a sales process or a negotiated agreement, with the option to pay per claim over x402.
Developers can deploy x401 today using the protocol, identity scheme, implementation guides and reference implementation at proof.com/x401. Consumers can set up their agent identity wallet at proof.com/digital-credential. Organizations requiring higher assurance, signed authorization evidence or credential issuance can register with Proof.
Proof will demonstrate the end-to-end experience at Money20/20 in Las Vegas, October 18–21, Booth #5069, and host developer sessions for organizations implementing x401.
