Coming Soon

Merchant SDK

The Merchant SDK checks AI agents' requests on a business's own server, against the business's own rules. The business's traffic never passes through Signet.

What a business sets

A business publishes its Signet policy on its own website, where people's devices read it directly. The policy says:

  • which actions need Signet, so browsing can stay open while, for example, starting a free trial requires a verified person;
  • per-person limits, such as one free trial per person, counted across all of a person's agents and accounts;
  • which actions need the person's approval, confirmed on their device for that one action.

What it checks

For each request to a protected action, the SDK checks, in order:

  1. Person: the request belongs to an open session, so a verified person stands behind it.
  2. Signature: the agent's key signed this exact request, in the format of HTTP Message Signatures (RFC 9421).
  3. Delegation: the agent's permission leads back to the person's device.
  4. Permission: both the agent's permission and the business's policy allow this action.
  5. Freshness: the request is recent and has not been used before.
  6. Limit: the person has allowance left under the business's rule.
Merchant SDKon protected actions
AgentClaudeSarah’s AI agent
Signed requestbuy_pairsize 8 · qty 1signed by the agent’s key
01Personverified, #7A91…
02Signatureagent’s key, exact request
03DelegationSarah authorized it
04Permissionbuy_pair is allowed
05Freshnessfirst use of this request
06Limit1 of 1 pair for #7A91…
DecisionALLOW#7A91…
Your appAtlas Runner 01size 8 · qty 1 · $180Order placedfor #7A91…
An example: Claude buys a pair of sneakers for Sarah at Atlas Supply, which sells one pair per person. The names and the request are illustrative.

Decisions

  • ALLOW: every check passes, and the business's app runs exactly the request that was checked.
  • VERIFY FIRST: the agent has no open session, so it asks its person to verify, then tries again.
  • DENY: any other check fails, or the person has reached the business's limit.

The SDK keeps its state on the business's server: sessions, per-person counts, and the requests already used. Signet sees none of it.

Status

The Merchant SDK is coming soon, and beta partners get it first. People bring Signet Agent with their AI agent. To take part, book a call.