What is KYH? How AI agents use it to pay
PilotKey date
Know Your Human (KYH) is Sardine's protocol for passing a shopper's device and network identifiers to a merchant when an AI agent checks out, so the merchant can tell that person from a bot.
Who backs it
Sardine. The Paypers reported on November 6, 2026 that Sardine is seeking design partners among agent developers and merchants.
What it is
Sardine describes Know Your Human as a way to bind a person to a shopping agent. The agent adds a few HTTP headers so the merchant can retrieve a device ID, a device fingerprint, and an IP address. Sardine's page calls email, phone, KYC, and identity verification possible extensions, not the default headers.
The Paypers reported the launch on November 6, 2026. It says many agent checkouts come from cloud browsers, with data-center IP addresses and automation user-agent strings, so fraud systems can decline a real customer's order.
Who it is for
An agent developer can bind the shopper's device with Sardine's SDK, or request a Method URL from a merchant that supports KYH and load it on the shopper's device. At checkout the merchant uses Sardine to read the device and IP signals.
A merchant can text the customer a verification link. Sardine says the link expires five minutes after it is created and can be opened up to three times. If it expires, a new link can be sent for the same session. The Paypers says Sardine has implemented KYH in its own Personal Agent. Neither source names other merchants that have adopted it.
Status
This tracker marks KYH as a pilot. The protocol is public, and Sardine says it complements existing agentic commerce protocols. Sardine is seeking design partners, so this is not a general merchant rollout.
KYH passes identifiers. It does not charge a card, and it does not replace a checkout protocol.
Note on this pageSardine's page calls email, phone, and KYC possible extensions. The Paypers lists email and phone among the identifiers and calls KYC an extended use case. This page does not treat email or phone as default headers. No merchant adoption list was published.
Sources
Which players support it
A player is listed only when its tracker row names KYH. Everyone else is not yet confirmed.
not yet confirmed
Tracker row: Sardine KYH
Recent related news
- Sardine launches Know Your Human for agent checkout · November 6, 2026
Questions people ask
What is KYH? How AI agents use it to pay
Know Your Human (KYH) is Sardine's protocol for passing a shopper's device and network identifiers to a merchant when an AI agent checks out, so the merchant can tell that person from a bot.
What is Know Your Human?
KYH is a Sardine protocol that lets an AI shopping agent pass a shopper's device ID, device fingerprint, and IP address to a merchant in a few HTTP headers. Sardine says this is meant to reduce false declines when an agent looks like a bot.
How does an agent connect the shopper's device?
The agent can embed Sardine's SDK, or it can request a Method URL from a merchant that supports KYH and load that URL on the shopper's device. The merchant then reads the device and IP signals from Sardine at checkout.
How long does the verification link last?
Sardine says a merchant can text the customer a verification link that expires five minutes after it is created and can be opened up to three times. If it expires, a new link can be sent for the same session.
Does KYH take a payment?
No. Sardine says KYH complements existing agentic commerce protocols. It passes identifiers so a merchant can recognize the person behind an agent. It does not itself charge a card. The Paypers said on November 6, 2026 that Sardine is seeking design partners, and neither source names merchants that have adopted it.