Carrier Services

A CarrierService lets your Shopify app provide real-time shipping rates at checkout by responding to rate requests at a public callback_url.

Source

• CarrierService (REST Admin API)
• Prefer GraphQL Admin API for new apps (REST legacy from Oct 2024)

How it works

1. App registers a carrier service with name, callback_url, and service_discovery
2. At checkout Shopify POSTs cart origin, destination, items, and currency to your URL
3. Your server returns JSON { "rates": [ … ] } with service_name, service_code, total_price (subunits), currency, optional delivery dates
4. Empty rates + 2xx = “cannot ship”; 4xx/5xx triggers backup rates

Access requirements

• App scope: write_shipping
• Store must be Advanced Shopify+, Shopify annual with carrier feature, or a development store

Rate limits & caching

• Dynamic timeouts: 10s / 5s / 3s based on requests per minute per shop-app pair
• Shopify caches identical rate requests ~15 minutes (variant IDs, addresses, weights, box dimensions)

Create example

curl -d '{"carrier_service":{"name":"My Rates","callback_url":"https://shipping.example.com/rates","service_discovery":true}}' \
  -X POST "https://{shop}.myshopify.com/admin/api/2026-01/carrier_services.json" \
  -H "X-Shopify-Access-Token: {token}" -H "Content-Type: application/json"

Related

• Shopify Dev
• Fulfillment Orders