Tutorial: Launch your first Checkout Store

In this tutorial you'll build a working Checkout Store (also called a micro-store) backed by your Shopify catalog. We'll use Comet's GraphQL API to:

1. Fetch products for a campaign collection
2. Create a checkout flow
3. Launch it as a Checkout Store via the Comet console

Prerequisites: Complete the Quick Start first — you need a connected Shopify store and a working API key.

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Overview

A Checkout Store in Comet is a standalone, URL-addressable store page designed for a specific campaign (product launch, seasonal sale, social commerce drop). It:

• Pulls products from your existing Shopify catalog
• Has its own URL (e.g. your-brand.satellites.comet.rocks/summer-launch)
• Handles checkout through Comet's federated cart API
• Can be embedded or shared as a link (e.g. on social media, email, ads)

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Part 1: Select your campaign products

First, identify the products you want to feature. Use tags or a collection ID from Shopify.

Query products by collection

query GetCampaignProducts($organizationId: ID!, $collectionId: String!) {
  productFind(
    organizationId: $organizationId
    filters: { externalCollectionId: $collectionId }
    pagination: { first: 20 }
  ) {
    nodes {
      id
      name
      description
      sku
      externalId
      type
      variantOf {
        id
        name
      }
    }
  }
}

TIP

externalId is the Shopify product GID. Use this to cross-reference with Shopify Admin.

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Part 2: Build the checkout flow

A complete checkout in Comet follows this sequence:

cartCreate → cartAddProducts → cartApplyShippingAddress
  → cartGetShippingMethods → cartCreatePaymentIntent → orderSubmit

1. Create a cart

mutation CreateCart($orgId: ID!) {
  cartCreate(input: { organizationId: $orgId }) {
    id
    bags {
      id
      merchantId
    }
  }
}

2. Add campaign products

mutation AddProducts($cartId: ID!, $productId: ID!) {
  cartAddProducts(input: {
    cartId: $cartId
    products: [{ productId: $productId, quantity: 1 }]
  }) {
    id
    bags {
      id
      products {
        productId
        quantity
        price {
          amount
          currencyCode
        }
      }
      subtotal {
        amount
        currencyCode
      }
    }
  }
}

3. Apply shipping address

mutation SetAddress($cartId: ID!) {
  cartApplyShippingAddress(input: {
    cartId: $cartId
    useSameForBilling: true
    address: {
      firstName: "Jane"
      lastName: "Doe"
      address1: "123 Main St"
      city: "New York"
      province: "NY"
      country: "US"
      zip: "10001"
      phone: "+1 212 555 0100"
    }
  }) {
    id
    bags {
      availableShippingMethods {
        id
        title
        price {
          amount
          currencyCode
        }
      }
    }
  }
}

4. Select shipping method

Take the id of your chosen shipping method from the response above:

mutation SetShipping($cartId: ID!, $bagId: ID!, $methodId: ID!) {
  cartApplyShippingMethods(input: {
    cartId: $cartId
    shippingMethods: [{ bagId: $bagId, shippingMethodId: $methodId }]
  }) {
    id
    total {
      amount
      currencyCode
    }
  }
}

5. Create payment intent

mutation CreatePayment($cartId: ID!) {
  cartCreatePaymentIntent(input: { cartId: $cartId }) {
    paymentIntentId
    clientSecret
    amount
    currency
  }
}

Use the clientSecret with Stripe.js to collect payment on the frontend.

6. Submit the order

mutation SubmitOrder($cartId: ID!) {
  orderSubmit(input: { cartId: $cartId }) {
    id
    status
    bags {
      id
      externalOrderId
    }
  }
}

On success, Comet places the order in Shopify. The externalOrderId is the Shopify order GID.

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Part 3: Launch your Checkout Store

Now publish this campaign as a live URL using the Comet console.

1. In console.comet.rocks, navigate to Storefronts
2. Click New Storefront
3. Set:
   • Name: Summer Launch
   • Slug: summer-launch → your URL will be your-brand.satellites.comet.rocks/summer-launch
   • Organization: select your Shopify org
4. Under Products, add the product IDs from Part 1
5. Click Publish

Your storefront is now live. Share the URL in ads, email, or social posts.

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What's next?

• Custom domain: Point a subdomain (e.g. launch.yourbrand.com) to satellites.comet.rocks via CNAME
• Styling: The satellite storefront supports custom CSS and logo upload from the console
• Discount codes: Use cartApplyCoupons to support promo codes
• Analytics: Each storefront tracks conversion events — view them in the console under Analytics
• Multi-merchant campaigns: Add products from multiple connected stores to the same cart

Explore the full Checkout API reference for advanced options.