Payments for AI agents, without giving them your keys

Agents are good at preparing payments and bad places to keep money. With send21 an agent creates payment requests and drafts through a scoped API key, and the payment is signed in a wallet the agent does not control.

Agent proposes, human signs

  • The agent calls create_payment_request or create_draft over MCP, or the same REST endpoints.
  • The payer, or the operator, reviews and signs in their own wallet.
  • The agent follows the result through get_draft_status or a webhook.
  • A leaked key can create instructions but cannot spend anything, because send21 holds nothing.

Built for automation

  • Idempotency keys make retries safe.
  • Batch creation of up to 25 drafts per call, and recurring templates.
  • Machine-readable pay pages and responses, with your order id echoed in every webhook.
  • Discovery files for agents: /llms.txt, /llms-full.txt and /openapi.json.

Selling to agents

A webshop can let an AI agent complete checkout: the backend creates a payment request per order, the agent picks a currency and pays from its operator's wallet, and the shop marks the order paid on draft.confirmed.

Related

This page is also available as Markdown: /ai-agent-payments.md. Questions: [email protected].