Safely let AI agents complete Shopify purchases

In short: give the agent a spend limit before it can check out on Shopify, and get a receipt after. Your agent should not create a checkout or complete an order without a bounded spend boundary and an audit trail. Paybond sits at the tool execution boundary — Harbor verifies the operation and amount before your handler runs.

• Spending limits

  Harbor verifies operation and amount before checkout runs.

• Audit evidence

  Signed completion digests bind the tool result to the intent.

• Merchant verification

  Binding metadata ties agent checkouts to your Shopify shop.

• Works with MCP agents

  Guard UCP Checkout MCP tools without rewriting your agent stack.

Why not just Shopify?

Shopify APIs create checkouts. They do not enforce per-agent spend limits, per-operation permission checks (capability tokens), or a signed receipt of what ran. Paybond adds that guardrail layer without replacing UCP or Admin.

How it works

{
  "operation": "commerce.checkout",
  "requested_spend_cents": 4500
}

3-minute quickstart

Smoke the sandbox contract with a sandbox intent — no Shopify credentials required:

paybond login
paybond agent sandbox smoke \
  --operation commerce.checkout \
  --requested-spend-cents 4500 \
  --evidence-preset cost_and_completion \
  --format table

paybond login
paybond agent sandbox smoke \
  --operation commerce.checkout \
  --requested-spend-cents 4500 \
  --evidence-preset cost_and_completion \
  --format table

Optional policy scaffold: paybond policy init --preset shopping.

When the smoke succeeds you should see:

• ✓ Spend approved
• ✓ Checkout completed
• ✓ Receipt generated

What success looks like

Wire middleware

Prefer Kit’s instrumentShopifyCheckout helper so binding metadata is injected on every call. Tenant and intent IDs come from the Paybond session binding — never from unauthenticated tool args.

import { Paybond, instrumentShopifyCheckout } from "@paybond/kit";

const paybond = await Paybond.open({ apiKey: process.env.PAYBOND_API_KEY! });

const instrumented = await instrumentShopifyCheckout(paybond, {
  policy: "./paybond.policy.yaml",
  executeCheckout: async (input) => {
    // Call UCP Checkout MCP / storefront with input.checkoutPayload
    // (note_attributes already include paybond_intent_id and tenant_id).
    return {
      status: "completed",
      cost_cents: 4500,
      order_id: "gid://shopify/Order/123",
      shop: "paybond-agent-commerce-dev.myshopify.com",
    };
  },
});

// After sandbox bind / attach — populate Shopify bindingRef, then bind Harbor:
instrumented.bindingRef.tenantId = tenantId;
instrumented.bindingRef.intentId = intentId;
await instrumented.bind({ intentId, capabilityToken });

import { Paybond, instrumentShopifyCheckout } from "@paybond/kit";

const paybond = await Paybond.open({ apiKey: process.env.PAYBOND_API_KEY! });

const instrumented = await instrumentShopifyCheckout(paybond, {
  policy: "./paybond.policy.yaml",
  executeCheckout: async (input) => {
    // Call UCP Checkout MCP / storefront with input.checkoutPayload
    // (note_attributes already include paybond_intent_id and tenant_id).
    return {
      status: "completed",
      cost_cents: 4500,
      order_id: "gid://shopify/Order/123",
      shop: "paybond-agent-commerce-dev.myshopify.com",
    };
  },
});

// After sandbox bind / attach — populate Shopify bindingRef, then bind Harbor:
instrumented.bindingRef.tenantId = tenantId;
instrumented.bindingRef.intentId = intentId;
await instrumented.bind({ intentId, capabilityToken });

Binding metadata

Every agent-initiated checkout must write binding metadata into Shopify so the async webhook path can resolve tenant scope.

Production checklist

Works with

Ready to test?

Related guides

• Configure Shopify settlement — tenant-admin prerequisites (manual capture, shop link)
• Settlement with payment providers — provider touchpoints, webhooks, capture timing