GraphQL vs REST: Choosing the Best API for Shopify Headless Commerce Development

Shopify has become a popular choice for businesses looking to power their eCommerce platforms. Its robust backend and extensive capabilities make it ideal for traditional storefronts and the modern headless commerce approach. As businesses move toward headless commerce development, the choice of API plays a pivotal role in determining success. Shopify supports two primary API paradigms: GraphQL and REST. Each has its strengths and weaknesses, making it essential to choose the right one for your specific needs. This article dives into the technical details of these APIs, helping you make an informed decision for your Shopify headless commerce development project.

What Is GraphQL and REST?

When developing a headless Shopify store, the API serves as the bridge between the backend (Shopify) and the front end, which can be a custom-built interface or a third-party solution.

GraphQL

GraphQL, a query language for APIs originally developed by Facebook, uses a single endpoint instead of multiple ones. This allows developers to specify exactly what data is needed, enabling them to fetch only the necessary information in a single request.

For example, GraphQL lets you retrieve only the product name, price, and inventory in one query if you’re building a product page. This reduces unnecessary data transfer, improving performance.

REST

REST (Representational State Transfer) is a widely used architectural style that relies on predefined endpoints. Each endpoint serves a specific purpose, such as retrieving product details or updating inventory. REST follows standard HTTP methods like GET, POST, PUT, and DELETE, making it straightforward for developers to understand and use.

For example, fetching a product’s information via REST requires calling the product endpoint, which might include data you don’t need, such as vendor details or timestamps. This will result in over-fetching or under-fetching the data.

Shopify’s API Options for Headless Development

Shopify offers two primary APIs for headless commerce development:

1. Storefront API
   This GraphQL-based API is tailored for front-end developers to fetch product information, collections, and checkout details. It powers the customer-facing side of a Shopify store, enabling custom storefronts that integrate with Shopify’s backend.
2. Admin API
   Available in both REST and GraphQL, this API is used for backend operations, such as managing orders, customers, and inventory. It allows businesses to handle the administrative tasks necessary for running their eCommerce operations.

Understanding these APIs’ roles is crucial in determining which to use for specific tasks in your headless commerce project.

Comparing GraphQL and REST for Shopify Headless Commerce Development

1. Data Fetching and Flexibility

GraphQL’s ability to fetch precise data in a single query gives it a significant advantage over REST. With REST, you often need to make multiple requests to gather the same information.

For example:

• REST: To fetch a product’s details and its associated inventory, you might call /products/{id} and /inventory/{id} separately.
• GraphQL: A single query retrieves both product and inventory data in one request.

GraphQL’s flexibility shines in complex scenarios where data from multiple relationships is required. REST, on the other hand, is limited to the structure defined by its endpoints.

2. Performance and Bandwidth Usage

GraphQL reduces over-fetching and under-fetching, resulting in better performance and reduced bandwidth usage. By fetching only the required data, GraphQL minimizes payload sizes, which is particularly beneficial for mobile-first and performance-sensitive applications.

In contrast, REST often returns more data than needed. For example, calling a product endpoint in REST might return metadata, vendor information, and timestamps, even if you only need the product’s name and price.

3. Developer Experience

GraphQL provides an interactive query playground (like GraphiQL) that allows developers to test queries and see real-time results. This feature improves productivity and debugging.

REST, while simpler in structure, lacks such an interactive interface. However, tools like Postman make working with REST APIs straightforward. REST’s simplicity can be advantageous for developers new to APIs, but its rigid structure may limit advanced use cases.

4. Error Handling

GraphQL centralizes error handling, providing clear and consistent messages when something goes wrong. For instance, if you query a non-existent field in GraphQL, it returns a detailed error message specifying the issue.

REST’s error handling varies across endpoints. While some REST APIs follow standard error codes (like 404 for not found or 500 for server errors), others may not provide consistent feedback, making debugging more challenging.

5. Caching

Caching is essential for improving API performance. REST leverages standard HTTP caching, allowing browsers and intermediaries to store responses and reuse them when needed. This built-in capability simplifies caching strategies.

GraphQL’s flexibility comes at the cost of caching complexity. Since each query can request different data, caching requires custom solutions, such as persisted queries or tools like Apollo Client.

6. Community Support and Ecosystem

REST has been around for decades, making it the most widely adopted API paradigm. Its maturity ensures extensive community support, documentation, and tools.

GraphQL, while newer, has rapidly gained traction. The ecosystem continues to grow with robust tools, libraries, and frameworks like Apollo and Relay. However, it still lags behind REST in terms of maturity.

ALSO READ: How Headless Shopify Boosts Luxury Brand Experiences?

Pros and Cons of Using GraphQL and REST with Shopify

GraphQL Pros

• Fetch only the data you need, reducing payload sizes.
• Combine multiple data sources into a single request.
• Improved developer experience with interactive tools like GraphiQL.

GraphQL Cons

• Requires learning new concepts, such as schema definitions and mutations.
• Custom caching strategies can be challenging to implement.

REST Pros

• Simple and intuitive structure.
• Built-in HTTP caching for efficient performance.
• Extensive community resources and tools.

REST Cons

• Limited flexibility in data fetching, often resulting in over-fetching or under-fetching.
• Multiple requests may be required for complex data relationships.

When to Use GraphQL or REST for Shopify Headless Commerce Development

Use GraphQL When:

• Building highly dynamic and interactive frontends, such as SPAs (Single Page Applications).
• The application requires complex data relationships (e.g., nested products and collections).
• Performance is critical, and you want to minimize API calls.

Use REST When:

• Developing simple applications or MVPs (Minimum Viable Products).
• HTTP caching is a priority for performance optimization.
• Your team prefers a straightforward and widely adopted API approach.

A Hybrid Approach

In some cases, combining GraphQL and REST makes sense. For example:

• Use the Storefront API (GraphQL) for customer-facing data like products and checkout.
• Use the Admin API (REST) for backend tasks like order management and inventory updates.

This approach allows you to leverage the strengths of both APIs.

Practical Examples: GraphQL vs REST in Action

Example 1: Fetching Product Data

REST:

GET /admin/api/2023-01/products/{id}.json

Returns all product details, including unnecessary metadata.

GraphQL:

{
  product(id: "gid://shopify/Product/12345") {
    title
    price
    inventory {
      available
    }
  }
}

• Fetches only the title, price, and inventory availability.

Example 2: Filtering and Sorting

• REST: Filtering options are predefined, requiring multiple queries to achieve complex filters.
• GraphQL: Filters and sorting can be customized in a single query, offering greater flexibility.

Example 3: Updating Inventory Levels

• REST:
  PUT /admin/api/2023-01/inventory_levels.json
  Requires a specific payload format.
• GraphQL:

mutation {
  inventoryAdjustQuantity(input: {inventoryLevelId: "12345", availableDelta: 10}) {
    inventoryLevel {
      available
    }
  }
}

Simple mutation with customizable fields.

Conclusion

Choosing between GraphQL and REST for Shopify headless commerce development depends on your project’s requirements and the expertise of your team. GraphQL excels in scenarios where flexibility, performance, and complex data relationships are critical. On the other hand, REST remains a reliable option for simpler applications, thanks to its straightforward design and built-in caching capabilities.

In many cases, a hybrid approach combining the strengths of both APIs can yield the best results. Whether you’re fetching product data, handling orders, or creating a custom frontend, understanding the nuances of GraphQL and REST will empower you to make the best decision for your Shopify headless commerce development project.

Ready to take your Shopify headless commerce development to the next level? Discover the range of Shopify Headless Commerce Development services offered by CartCoders. Whether you’re looking to build a dynamic, high-performance eCommerce platform using GraphQL, REST, or a blend of both, our expert team is equipped to deliver tailored solutions that meet your business needs.

Learn more about our full suite of Shopify services or contact us today to kickstart your project with a consultation. Let’s create a seamless and powerful shopping experience together!