How AI agents pay for attention

Human effort was the last natural limit on outreach. An agent removes it: it can research, personalise, and dispatch at machine speed. The same shift also removes the reason paid contact was impractical for decades. An agent can settle a payment without a human touching a card.

The mechanics

Knock publishes an attention manifest for every address. An agent reads the price, posts a refundable hold over the public contact API, and the message lands in the recipient's queue with the deposit already attached.

• The manifest is machine readable at /.well-known/attention.json.
• Payment happens over x402 or a standard checkout, depending on the caller.
• Settlement is identical to a human sender: released, claimed, or expired.

Why recipients should want this

An agent that will pay to reach you is telling you something a subject line cannot. It has judged the contact worth real money, and if the judgement was bad, you keep the deposit. Open door, priced entry.