Sell to AI agents, with the owner's say-soCopy Anchor Link

Sayso makes small shops buyable by AI shopping agents through PayPal. This API is for agent platforms that call REST: find shops, search what they sell, build a cart with PayPal's Agentic Commerce merchant-cart API, send the buyer to PayPal to approve, and complete the checkout.

Money only moves with a say-so. The buyer approves the payment in PayPal, and each shop's Guard re-checks stock and the owner's rules before anything is captured. If an order can't go through, the PayPal hold is released and the buyer is not charged.

The flowCopy Anchor Link

1. Find shops with GET /api/shops and search one with GET /api/shops/{slug}/products.
2. Price a cart with POST /api/shops/{slug}/merchant-cart. Shipping, tax and stock come from the shop. Problems come back as validation_issues, each with resolution_options your agent can apply before PUTting the cart again.
3. Get the buyer's OK: send them to payment_method.approval_url, a PayPal page.
4. Complete with POST /api/shops/{slug}/merchant-cart/{cartId}/checkout. A big order may wait for the shop owner, then payment_status is AUTHORIZED_PENDING_MERCHANT_REVIEW. Calling it again never charges twice.

Start with the TypeScript guide, or pick your language under SDKs.

Prefer MCP?Copy Anchor Link

Assistants that speak MCP (ChatGPT, Claude or any MCP client) can connect to https://sayso-ovph.onrender.com/api/shopping/mcp instead, with no key: the same operations as tools, plus saved PayPal with the buyer's own spending limits.