Salesforce SOAP API: Integrate Salesforce with External Systems Using WSDL and Web Services

 This article explains how to integrate an external system with Salesforce using the SOAP API and Salesforce-generated WSDLs.

Step 1: Access the WSDL from Salesforce

Navigate to Setup > Develop > API (Classic) or Setup > Integrations > API (Lightning Experience) to download the Enterprise or Partner WSDL. Choose the Enterprise WSDL if building against a specific org, or the Partner WSDL if building a multi-org integration tool.

Step 2: Generate Client Stubs in Your External System

Import the WSDL into your external system's development environment to auto-generate client stubs. These stubs provide pre-built classes for all Salesforce operations (query, create, update, delete, upsert) and the corresponding object types.

Step 3: Configure the API Endpoint URL

Set the API endpoint URL in your integration to target your Salesforce org's SOAP API endpoint. For Enterprise WSDL, the endpoint format is: https://[instance].salesforce.com/services/Soap/c/[version]. The correct endpoint URL is returned in the Login response.

Step 4: Define Data Synchronization Logic

In your external system's web service, define the conditions that trigger Salesforce data operations. For example, when a record is created in your ERP, call the Salesforce create() method to insert a corresponding record in Salesforce.

Additional resources for SOAP API 

• Introducing SOAP API
• Integrating with the Force.com Platform
• Integration Patterns and Practices
• Which API do I use?