9 API Integration Services for B2B SaaS Companies

API integration services help software companies connect applications, automate data exchange, and reduce the engineering effort required to maintain multiple integrations. Demand for these services continues to grow: the global market reached $5.54 billion in 2026 and is projected to reach $7.68 billion by 2032.

However, API integration services use very different models. A SaaS company can build integrations in-house, work with a custom integration provider, use an iPaaS, or connect through a unified API. The right approach depends on the systems you need to connect, the workflows your product supports, and the resources required to maintain those integrations over time. As a result, this guide compares nine API integration services and explains how to evaluate them for B2B SaaS use cases.

What Are API Integration Services?

API integration services connect software applications through their APIs so they can exchange data and automate workflows. Depending on the integration model, they can handle tasks such as authentication, data mapping, synchronization, error handling, and communication between different systems.

For SaaS companies, these services can reduce the amount of custom integration logic developers need to build and maintain. However, custom integration providers, iPaaS platforms, and unified APIs solve this problem in different ways, so the right option depends on the product and its integration needs.

For a detailed explanation of how these services work, see our guide to API integration services and their core components.

How to Choose an API Integration Service

The right API integration service depends on your product architecture, the number of integrations you need, and who will maintain those integrations over time. For B2B SaaS companies, the initial development effort is only one part of the decision.

When comparing API integration services, evaluate the following factors:

• Integration coverage: Check whether the provider supports the platforms and applications your customers actually use.
• Integration model: Determine whether you need custom development, an iPaaS, workflow automation, or a unified API.
• Data normalization: Check whether your developers need to handle a different data model for every connected platform.
• API features: Review supported read and write operations, webhooks, filtering, pagination, and platform-specific limitations.
• Maintenance responsibility: Define who will handle authentication changes, deprecated endpoints, API version updates, and integration failures.
• Developer experience: Evaluate documentation, test environments, SDKs, monitoring tools, and technical support.
• Total cost of ownership: Compare the provider cost with the engineering resources required to build and maintain integrations internally.

9 API Integration Services to Consider

API integration services use different approaches to connecting applications, automating workflows, and managing data exchange. The options below include unified APIs, iPaaS platforms, workflow automation tools, and enterprise integration solutions. The right choice depends on your product architecture, integration scope, and long-term maintenance needs.

1. API2Cart

Best for: B2B SaaS vendors that need to connect their software with multiple eCommerce platforms and marketplaces.

Integration model: Unified eCommerce API.

Among the API integration services in this comparison, API2Cart is designed specifically for software vendors that need eCommerce integrations. Additionally, it provides a single API interface for connecting SaaS applications with 80+ eCommerce platforms and marketplaces, including WooCommerce, Shopify, BigCommerce, Magento, eBay, Amazon, Etsy, Wix, Shopee, Temu, TikTok Shop, Flipkart, and others.

Instead of building and maintaining separate integration logic for every platform, developers can use normalized API methods to work with common eCommerce data such as products, orders, customers, categories, inventory, prices, and shipments. API2Cart also supports event-driven workflows through webhooks, allowing applications to react to supported store events without relying only on repeated polling.

Key strengths: eCommerce specialization, normalized data access across multiple platforms, REST API, webhooks, SDKs, OpenAPI specification, and Postman collection.

Consideration: API2Cart is focused specifically on eCommerce integrations rather than general-purpose enterprise application integration.

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API2Cart Integration Example

For example, a SaaS application can use the order.list method to retrieve orders from a connected store. The method supports filtering and pagination, while API2Cart returns order data through a normalized API structure across supported eCommerce integrations.

Sample API Response

{
  "return_code": 0,
  "return_message": "string",
  "pagination": {
    "previous": "string",
    "next": "string",
    "additional_fields": {},
    "custom_fields": {}
  },
  "result": {
    "orders_count": 0,
    "order": [
      {
        "id": "string",
        "order_id": "string",
        "basket_id": "string",
        "channel_id": "string",
        "customer": {
          "id": "string",
          "email": "string",
          "first_name": "string",
          "last_name": "string",
          "phone": "string",
          "additional_fields": {},
          "custom_fields": {}
        },
        "create_at": {
          "value": "string",
          "format": "string",
          "additional_fields": {},
          "custom_fields": {}
        },
        "currency": {
          "id": "string",
          "name": "string",
          "iso3": "string",
          "symbol_left": "string",
          "symbol_right": "string",
          "rate": 0,
          "avail": true,
          "default": true,
          "additional_fields": {},
          "custom_fields": {}
        },
        "shipping_address": {
          "id": "string",
          "type": "string",
          "first_name": "string",
          "last_name": "string",
          "postcode": "string",
          "address1": "string",
          "address2": "string",
          "phone": "string",
          "phone_mobile": "string",
          "city": "string",
          "country": {
            "code2": "string",
            "code3": "string",
            "name": "string",
            "additional_fields": {},
            "custom_fields": {}
          },
          "state": {
            "code": "string",
            "name": "string",
            "additional_fields": {},
            "custom_fields": {}
          },
          "company": "string",
          "fax": "string",
          "website": "string",
          "gender": "string",
          "region": "string",
          "default": true,
          "tax_id": "string",
          "identification_number": "string",
          "alias": "string",
          "additional_fields": {},
          "custom_fields": {}
        },
        "billing_address": {
          "id": "string",
          "type": "string",
          "first_name": "string",
          "last_name": "string",
          "postcode": "string",
          "address1": "string",
          "address2": "string",
          "phone": "string",
          "phone_mobile": "string",
          "city": "string",
          "country": {
            "code2": "string",
            "code3": "string",
            "name": "string",
            "additional_fields": {},
            "custom_fields": {}
          },
          "state": {
            "code": "string",
            "name": "string",
            "additional_fields": {},
            "custom_fields": {}
          },
          "company": "string",
          "fax": "string",
          "website": "string",
          "gender": "string",
          "region": "string",
          "default": true,
          "tax_id": "string",
          "identification_number": "string",
          "alias": "string",
          "additional_fields": {},
          "custom_fields": {}
        },
        "payment_method": {
          "name": "string",
          "additional_fields": {},
          "custom_fields": {}
        },
        "shipping_method": {
          "name": "string",
          "additional_fields": {},
          "custom_fields": {}
        },
        "shipping_methods": [
          {
            "name": "string",
            "additional_fields": {},
            "custom_fields": {}
          }
        ],
        "status": {
          "id": "string",
          "name": "string",
          "history": [
            {
              "id": "string",
              "name": "string",
              "modified_time": {
                "value": "string",
                "format": "string",
                "additional_fields": {},
                "custom_fields": {}
              },
              "notify": true,
              "comment": "string",
              "additional_fields": {},
              "custom_fields": {}
            }
          ],
          "refund_info": {
            "shipping": 0,
            "fee": 0,
            "tax": 0,
            "total_refunded": 0,
            "time": {
              "value": "string",
              "format": "string",
              "additional_fields": {},
              "custom_fields": {}
            },
            "comment": "string",
            "refunded_items": [
              {
                "product_id": "string",
                "variant_id": "string",
                "order_product_id": "string",
                "qty": 0,
                "refund": 0,
                "additional_fields": {},
                "custom_fields": {}
              }
            ],
            "additional_fields": {},
            "custom_fields": {}
          },
          "additional_fields": {},
          "custom_fields": {}
        },
        "totals": {
          "total": 0,
          "subtotal": 0,
          "shipping": 0,
          "tax": 0,
          "discount": 0,
          "additional_fields": {},
          "custom_fields": {}
        },
        "total": {
          "subtotal_ex_tax": 0,
          "wrapping_ex_tax": 0,
          "shipping_ex_tax": 0,
          "total_discount": 0,
          "total_tax": 0,
          "total": 0,
          "total_paid": 0,
          "additional_fields": {},
          "custom_fields": {}
        },
        "discounts": [
          {
            "code": "string",
            "value": 0,
            "type": "string",
            "additional_fields": {},
            "custom_fields": {}
          }
        ],
        "order_products": [
          {
            "product_id": "string",
            "order_product_id": "string",
            "model": "string",
            "name": "string",
            "price": 0,
            "price_inc_tax": 0,
            "quantity": 0,
            "discount_amount": 0,
            "total_price": 0,
            "tax_percent": 0,
            "tax_value": 0,
            "tax_value_after_discount": 0,
            "options": [
              {
                "option_id": "string",
                "name": "string",
                "value": "string",
                "price": 0,
                "weight": 0,
                "type": "string",
                "product_option_value_id": "string",
                "additional_fields": {},
                "custom_fields": {}
              }
            ],
            "variant_id": "string",
            "weight_unit": "string",
            "weight": 0,
            "barcode": "string",
            "parent_order_product_id": "string",
            "additional_fields": {},
            "custom_fields": {}
          }
        ],
        "bundles": [
          {
            "product_id": "string",
            "order_product_id": "string",
            "model": "string",
            "name": "string",
            "price": 0,
            "price_inc_tax": 0,
            "quantity": 0,
            "discount_amount": 0,
            "total_price": 0,
            "tax_percent": 0,
            "tax_value": 0,
            "tax_value_after_discount": 0,
            "options": [
              {
                "option_id": "string",
                "name": "string",
                "value": "string",
                "price": 0,
                "weight": 0,
                "type": "string",
                "product_option_value_id": "string",
                "additional_fields": {},
                "custom_fields": {}
              }
            ],
            "variant_id": "string",
            "weight_unit": "string",
            "weight": 0,
            "barcode": "string",
            "parent_order_product_id": "string",
            "additional_fields": {},
            "custom_fields": {}
          }
        ],
        "modified_at": {
          "value": "string",
          "format": "string",
          "additional_fields": {},
          "custom_fields": {}
        },
        "finished_time": {
          "value": "string",
          "format": "string",
          "additional_fields": {},
          "custom_fields": {}
        },
        "comment": "string",
        "store_id": "string",
        "warehouses_ids": [
          "string"
        ],
        "refunds": [
          {
            "id": "string",
            "shipping": 0,
            "fee": 0,
            "tax": 0,
            "total": 0,
            "modified_time": {
              "value": "string",
              "format": "string",
              "additional_fields": {},
              "custom_fields": {}
            },
            "comment": "string",
            "items": [
              {
                "product_id": "string",
                "variant_id": "string",
                "order_product_id": "string",
                "qty": 0,
                "refund": 0,
                "additional_fields": {},
                "custom_fields": {}
              }
            ],
            "additional_fields": {},
            "custom_fields": {}
          }
        ],
        "gift_message": "string",
        "order_details_url": "string",
        "additional_fields": {},
        "custom_fields": {}
      }
    ],
    "additional_fields": {},
    "custom_fields": {}
  },
  "additional_fields": {},
  "custom_fields": {}
}

Furthermore, it provides users with a FREE trial to see how they can solve their business needs.

2. Jitterbit

Best for: Companies that need to connect applications, APIs, data, and business processes across cloud and on-premises environments.

Integration model: iPaaS, API management, and automation platform.

Jitterbit takes a broad approach to API integration services through its Harmony platform. In particular, it supports application and data integration, workflow orchestration, API management, EDI, and low-code application development within one environment.

Teams can use Jitterbit to build integrations, expose integration workflows as managed APIs, and connect both cloud and privately hosted systems. Furthermore, its API management features also cover API creation, publishing, security, monitoring, and lifecycle management.

Key strengths: Low-code integration, API management, workflow automation, cloud and on-premises connectivity, and support for broader enterprise integration scenarios.

Consideration: Jitterbit covers a wider integration and automation scope than a specialized unified API, so the implementation model depends on the workflows and systems an organization needs to connect.

3. Boomi

Best for: Companies with complex application, API, and data integration needs across multiple environments.

Integration model: Enterprise iPaaS and automation platform.

Boomi provides integration and automation features for connecting applications, APIs, data, and other enterprise systems. Moreover, its platform supports cloud and on-premises integration scenarios and includes pre-built connectors and reusable integration components.

As an API integration solution, Boomi is designed for companies that need to coordinate multiple systems and integration patterns rather than maintain isolated point-to-point connections.

Key strengths: Enterprise application integration, data connectivity, API integration, process automation, and reusable connectors.

Consideration: Boomi is primarily designed for broad enterprise integration environments, which can make it a different fit from a category-specific unified API used inside a SaaS product.

4. Workato

Best for: Enterprises that need to integrate applications and automate cross-system business processes.

Integration model: Enterprise iPaaS and orchestration platform.

Workato combines integration, workflow automation, data orchestration, API management, and AI features within one platform. Moreover, it can connect cloud applications, databases, APIs, and on-premises systems and orchestrate workflows across them.

Among the API integration services in this comparison, Workato places a strong emphasis on enterprise-wide automation. Teams can use pre-built connectors or create custom connectors for systems that expose REST or SOAP APIs.

Key strengths: Enterprise orchestration, application integration, workflow automation, API management, custom connectors, and hybrid connectivity.

Consideration: Workato is optimized for broad workflow orchestration and enterprise automation rather than providing one normalized data model across a specific category of third-party APIs.

5. Zapier

Best for: Teams that need to automate workflows between SaaS applications with minimal development effort.

Integration model: Workflow and AI automation platform.

Zapier connects applications, data, and business processes through automated workflows. Additionally, its core workflow model uses triggers and actions, allowing one application event to initiate tasks in other connected applications.

Zapier also supports no-code, low-code, and developer-oriented automation options, making it useful for teams that need to automate operational processes without building every application connection from scratch.

Key strengths: Large application ecosystem, quick workflow setup, trigger-and-action automation, and options for custom actions and private apps.

Consideration: Zapier primarily solves workflow automation needs. Specifically, it is not a direct replacement for a normalized API layer designed to become part of a SaaS product's own integration architecture.

6. Informatica

Best for: Enterprises with complex application, API, data integration, and data management needs.

Integration model: Enterprise iPaaS and data integration platform.

Informatica provides API, application, and data integration features through its Intelligent Data Management Cloud. In addition, its integration services support real-time application connectivity, business process automation, cloud and on-premises systems, and API lifecycle management.

The broader Informatica platform also combines integration with data management features such as data quality, governance, master data management, and B2B connectivity. In this way, this makes it particularly relevant to enterprises where integration is part of a larger data architecture.

Key strengths: Application and API integration, data integration, enterprise data management, API lifecycle features, and hybrid cloud connectivity.

Consideration: Informatica has a broad enterprise data-management scope that may exceed the needs of SaaS teams looking only for a focused set of customer-facing integrations.

7. Celigo

Best for: Companies that need to integrate business applications and automate processes across systems such as ERP, CRM, eCommerce, and other SaaS tools.

Integration model: iPaaS and intelligent automation platform.

Celigo provides application integration and automation features through an iPaaS platform. As a result, it supports pre-built connectors, configurable workflows, API management, B2B/EDI processes, data ingestion, and centralized integration management.

Celigo is designed to help IT and business teams build and operate workflows across multiple applications while maintaining centralized visibility and governance.

Key strengths: Application integration, pre-built connectors and templates, process automation, API management, B2B integration, and centralized governance.

Consideration: Celigo focuses on orchestrating integrations and business processes between applications rather than exposing one standardized API model across an entire software category.

8. MuleSoft

Best for: Large companies that need to build, manage, secure, and reuse APIs and integrations across complex application environments.

Integration model: API management and enterprise integration platform.

MuleSoft provides API integration services through Anypoint Platform, which combines tools for API design, development, integration, management, security, governance, and monitoring.

Developers can use the platform to build APIs and integrations, connect cloud and on-premises systems, manage API traffic and security policies, and reuse APIs and integration assets across different projects.

Key strengths: Full API lifecycle management, enterprise integration, API security and governance, reusable integration assets, and hybrid deployment support.

Consideration: MuleSoft targets complex enterprise API and integration architectures, so its scope and implementation needs can be greater than those of a specialized API integration service.

9. Oracle Integration

Best for: Enterprises that need to connect cloud and on-premises applications, automate business processes, and integrate systems within or beyond the Oracle ecosystem.

Integration model: Enterprise integration and automation platform.

Oracle Integration provides application and data integration, process automation, and connectivity features in a managed cloud environment. Furthermore, it supports integrations between cloud and on-premises applications and provides adapters for Oracle and third-party systems.

The platform includes tools for data mapping, monitoring integration activity, managing errors, and building automated business processes. As a result, its native Oracle SaaS connectivity can be particularly relevant to companies already using Oracle enterprise applications.

Key strengths: Cloud and on-premises application integration, pre-built adapters, data mapping, process automation, monitoring, and Oracle ecosystem connectivity.

Consideration: Oracle Integration is primarily designed for enterprise integration and automation scenarios and can be especially relevant when Oracle applications already form part of the organization's technology stack.

Conclusion

API integration services can reduce the complexity of connecting applications, exchanging data, and maintaining integrations over time. However, the right solution depends on your architecture, the systems you need to support, and whether you need workflow automation, enterprise integration, custom development, or a unified API.

For B2B SaaS vendors that need to connect with multiple eCommerce platforms and marketplaces, API2Cart provides a unified API for working with products, orders, customers, inventory, shipments, and other eCommerce data through a single integration.

Ready to explore API2Cart for your SaaS product? Sign up for free and start testing the integration.