Top 10 The Best APIs of eCommerce Platforms

An API of an eCommerce platform is a core part of modern eCommerce software integration. According to the 2025 State of the API Report, 82% of organizations use an API-first approach to some degree. Moreover, 69% of respondents spend at least 10 hours per week on API-related work.

For eCommerce software providers, APIs provide access to data and operations available on shopping platforms and marketplaces. However, every platform can expose different endpoints, authentication methods, data structures, rate limits, and API capabilities. Therefore, developers need to understand these differences before building an integration.

For example, an order management system can use an eCommerce platform API to retrieve new orders. Similarly, inventory software can use APIs to read or update available stock. The exact operations depend on the capabilities and permissions provided by each platform.

This guide explains how APIs of eCommerce platforms work and what developers should consider before integrating with them. It also compares popular eCommerce APIs and explores an approach to connecting software with multiple platforms through one integration.

What Is an API of an eCommerce Platform?

An API of an eCommerce platform provides programmatic access to supported platform data and operations. External software can use it to retrieve or modify resources without interacting with the platform's user interface.

Depending on the platform, these resources may include products, orders, customers, inventory, prices, shipments, and payments. However, API capabilities vary between platforms. Each provider can define its own endpoints, authentication requirements, data models, permissions, and usage limits.

How Does an eCommerce Platform API Work?

Most eCommerce APIs use a request-response model. An application sends a request to an API endpoint for a specific resource or operation. The platform then processes the request and returns a response in a supported format, commonly JSON.

REST-based eCommerce APIs commonly use HTTP methods such as:

• GET to retrieve resources such as orders, products, or customers.
• POST to create supported resources or initiate operations.
• PUT or PATCH to update existing resources.
• DELETE to remove resources when the platform supports this operation.

For example, an OMS may retrieve new orders and send supported fulfillment updates. Meanwhile, inventory software may retrieve product data and update stock quantities. The available operations depend on the API provided by each eCommerce platform.

Why APIs of eCommerce Platforms Matter for Software Providers

APIs of eCommerce platforms enable SaaS providers to build commerce functionality into their own products. For example, they can support order import, inventory updates, product management, fulfillment workflows, and customer data exchange.

This connectivity is particularly important for OMS, WMS, PIM, ERP, shipping, inventory, and multichannel solutions. However, supporting more platforms also increases integration complexity. Developers must account for differences in API capabilities, authentication, data structures, limits, and ongoing API changes.

Popular APIs of eCommerce Platforms

Popular eCommerce platforms provide APIs for products, orders, inventory, customers, fulfillment, and other commerce operations. However, their API architectures and capabilities differ. Developers should evaluate the available resources, authentication, versioning, and platform-specific limitations before building an integration.

eBay API

eBay provides RESTful APIs for selling, buying, inventory, fulfillment, and other marketplace workflows. Its REST APIs use OAuth 2.0 access tokens for authentication and authorization.

Magento API

Adobe Commerce and Magento Open Source provide REST, GraphQL, and SOAP web APIs. Developers can use them to work with supported catalog, customer, order, and other commerce functionality.

WooCommerce API

WooCommerce provides REST APIs for working with store resources such as products, orders, customers, and other supported data. Available capabilities depend on the WooCommerce API and extensions used by the store.

Shopify API

Shopify provides the GraphQL Admin API for building apps and integrations that interact with store data. The REST Admin API is now legacy, and new integrations should use GraphQL.

BigCommerce API

BigCommerce provides APIs for catalog, orders, customers, inventory, channels, and other commerce operations. Its developer APIs support integrations between BigCommerce stores and external software systems.

Squarespace API

Squarespace Commerce APIs cover products, inventory, orders, transactions, contacts, discounts, and other commerce resources. The platform also provides webhook subscriptions for supported events.

Ecwid API

Ecwid provides APIs for accessing and managing supported store data, including products, orders, customers, and inventory. It also supports webhooks for responding to available store events.

Etsy API

Etsy Open API v3 supports inventory, listings, sales orders, shops, and other marketplace workflows. It uses API credentials and OAuth 2.0 authorization for endpoints that require scoped access.

Wix API

Wix provides APIs for products, inventory, orders, and other eCommerce functionality. Its newer Catalog V3 APIs add expanded product, variant, inventory, and multi-location capabilities.

MercadoLibre API

Mercado Libre provides APIs for marketplace integrations across Latin American markets. Developers can work with supported listings, orders, users, shipping, and other marketplace resources.

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What Is an API of an eCommerce Platform?

An API of an eCommerce platform provides programmatic access to supported platform data and operations. External software can use it to retrieve or modify resources without interacting with the platform's user interface.

Depending on the platform, these resources may include products, orders, customers, inventory, prices, shipments, and payments. However, API capabilities vary between platforms. Each provider can define its own endpoints, authentication requirements, data models, permissions, and usage limits.

How Does an eCommerce Platform API Work?

Most eCommerce APIs use a request-response model. An application sends a request to an API endpoint for a specific resource or operation. The platform then processes the request and returns a response in a supported format, commonly JSON.

REST-based eCommerce APIs commonly use HTTP methods such as:

• GET to retrieve resources such as orders, products, or customers.
• POST to create supported resources or initiate operations.
• PUT or PATCH to update existing resources.
• DELETE to remove resources when the platform supports this operation.

For example, an OMS may retrieve new orders and send supported fulfillment updates. Meanwhile, inventory software may retrieve product data and update stock quantities. The available operations depend on the API provided by each eCommerce platform.

Why APIs of eCommerce Platforms Matter for Software Providers

APIs of eCommerce platforms enable SaaS providers to add commerce functionality to their own products. For example, they can support order import, inventory updates, product management, fulfillment workflows, and customer data exchange.

Through these APIs, software can manage product catalogs, import orders, update inventory, and process fulfillment data. It can also work with customer information where the platform provides access to it.

In addition, APIs connect eCommerce platforms with external business systems. These can include shipping software, tax solutions, ERP systems, PIM tools, and order management systems.

This connectivity is particularly important for OMS, WMS, PIM, ERP, shipping, inventory, and multichannel solutions. However, supporting more platforms also increases integration complexity. Developers must account for differences in API capabilities, authentication, data structures, limits, and ongoing API changes.

How to Integrate with Multiple eCommerce Platform APIs

Building integrations with multiple eCommerce platforms can require significant development resources. Each platform has its own API architecture, authentication, data models, limits, and supported operations. In addition, developers need to maintain these connections as external APIs change.

One approach is to build and maintain every integration separately. However, this becomes more complex as a SaaS product adds more sales channels. Alternatively, developers can use a unified API to access multiple eCommerce platforms through one integration layer.

API2Cart provides a unified API for connecting eCommerce software with 80+ eCommerce integrations. Instead of implementing a separate interface for every supported platform, developers can use standardized API methods for common commerce operations.

API2Cart provides 100+ API methods for working with supported products, orders, customers, categories, inventory, prices, shipments, and other eCommerce data. For example, software vendors can use the same API integration layer to retrieve orders or synchronize inventory across supported platforms.

However, the available methods, fields, and operations can differ between platforms. Therefore, developers should verify the required capabilities before implementing a specific integration workflow. See the API2Cart documentation for supported methods, parameters, and response structures.

Advantages of Using API2Cart for eCommerce Platform Integration

API2Cart helps eCommerce software vendors reduce the amount of platform-specific integration work required to support multiple sales channels. Its unified API provides a common integration layer for 80+ eCommerce integrations.

• One API for multiple eCommerce integrations. Developers can connect their software with supported shopping platforms and marketplaces through a unified API. This reduces the need to build a separate integration architecture for every platform.
• 100+ API methods. API2Cart provides 100+ methods for working with supported products, orders, customers, categories, inventory, prices, shipments, and other eCommerce data.
• Standardized data access. Software vendors can use common API methods and response structures across supported integrations. However, available fields and operations can vary depending on each platform's capabilities.
• Reduced integration maintenance. API2Cart maintains its connections as supported eCommerce APIs evolve. Therefore, SaaS teams can reduce the amount of platform-specific integration maintenance handled within their own applications.
• Support for common eCommerce workflows. The API can support workflows such as order import, inventory synchronization, product management, and fulfillment data exchange where the connected platform provides the required functionality.

eCommerce API Integration Example with API2Cart

API2Cart provides standardized API methods for working with supported eCommerce platforms. For example, a WMS or OMS can use the order.list method to retrieve orders from a connected Magento store.

The same API2Cart method can also be used with other supported platforms. However, available parameters and response fields may differ depending on the capabilities of each platform.

Request Example

The following example retrieves up to 10 orders created within a specified period:

GET https://api.api2cart.com/v1.1/order.list.json?count=10&created_from=2026-09-01T00:00:00Z&created_to=2026-09-22T23:59:59Z

Headers:
x-api-key: YOUR_API_KEY
x-store-key: YOUR_STORE_KEY

The request uses the following parameters:

• count defines the number of orders requested.
• created_from filters orders created from the specified date and time.
• created_to filters orders created up to the specified date and time.
• x-api-key authenticates access to the API2Cart API.
• x-store-key identifies the connected store.

Response Example

A successful order.list request returns a standardized API2Cart response. The exact order fields depend on the connected platform and requested response data.

{
  "return_code": 0,
  "return_message": "",
  "pagination": {
    "previous": null,
    "next": null
  },
  "result": {
    "orders_count": 1,
    "order": [
      {
        "id": "000000001",
        "order_id": "1"
      }
    ]
  }
}

The result.order array contains the retrieved orders. Depending on the request and platform, an order can also include customer data, statuses, totals, addresses, products, shipping information, refunds, and other supported fields.

For production integrations, developers should request only the data required by their application. They should also verify which methods, parameters, and fields are supported for the target eCommerce platform.

See the API2Cart Interactive Documentation for the current order.list parameters and response structure.

Conclusion: Simplify eCommerce API Integration with API2Cart

Integrating with multiple eCommerce platform APIs requires developers to work with different authentication methods, data models, endpoints, and platform-specific requirements. In addition, each direct integration requires ongoing maintenance as external APIs evolve.

API2Cart provides a unified API for 80+ eCommerce integrations. Software vendors can use standardized API methods to work with supported orders, products, customers, inventory, shipments, and other commerce data.

As a result, SaaS providers can reduce platform-specific development and maintenance work. They can also expand their integration ecosystem through a common API architecture. However, available methods, fields, and operations depend on the capabilities of each connected platform.

If your software needs to connect with multiple eCommerce platforms and marketplaces, you can test the required API2Cart integrations before implementation.

Start a free API2Cart trial and explore the integrations required for your software.