WSDL in Salesforce: Enterprise vs Partner WSDL Explained

What is WSDL in Salesforce?

WSDL stands for Web Services Description Language.
It’s an XML-based document that describes how to connect to and interact with a web service.

In Salesforce, a WSDL file acts like a contract between Salesforce and another system, telling it:

What functions/methods are available
What inputs (parameters) are needed
What outputs (responses) to expect
The endpoint URL of the service

Types of WSDL in Salesforce:

There are two main types: Enterprise WSDL and Partner WSDL. While they both allow integration, they differ in structure, flexibility, and use cases.

Let’s break it down in detail:

1. Enterprise WSDL

Definition:
Enterprise WSDL is a strongly typed WSDL generated for a specific Salesforce org. It contains metadata about all objects and fields in that org.

Key Characteristics:

Feature	Enterprise WSDL
Type	Strongly typed
Org-Specific	Yes, tied to a single Salesforce org
Fields/Objects	Includes all custom fields and objects in that org
Stability	Changes in org (adding/deleting fields) require regenerating WSDL
Use Case	Best for internal integrations where the org schema is known and stable
Ease of Use	Easier to work with in strongly typed languages like Java or C# because classes map directly to Salesforce objects

Example:
If you have a Contact object with custom field Custom_Field__c, the generated class will include that field explicitly.

2. Partner WSDL

Definition:
Partner WSDL is a loosely typed WSDL that works with any Salesforce org. It uses generic data structures like sObject instead of specific object classes.

Key Characteristics:

Feature	Partner WSDL
Type	Loosely typed
Org-Specific	No, works across multiple orgs
Fields/Objects	Does not include org-specific fields; uses sObject to represent objects
Stability	More flexible; changes in org schema do not require regenerating WSDL
Use Case	Best for applications integrating with multiple orgs or when object schema may change
Ease of Use	More complex to work with in strongly typed languages because you have to handle fields dynamically

Example:
Contact object would be represented as a generic sObject. Fields are accessed dynamically using key-value pairs instead of predefined class members.

Key Differences

Aspect	Enterprise WSDL	Partner WSDL
Typing	Strongly typed	Loosely typed
Org Dependency	Tied to one org	Works with any org
Schema Changes	Requires regenerating WSDL if schema changes	No regeneration needed
Ease of Use	Easier for coding, compile-time checking	More flexible, runtime handling required
Best For	Internal integrations with fixed schema	Multi-org apps or dynamic integrations

Choosing Between Them

Use Enterprise WSDL when:
- You know the object structure in advance.
- You’re building internal apps for a single org.
- You want compile-time checks and easier development.
Use Partner WSDL when:
- You’re building apps that need to work with multiple Salesforce orgs.
- The object schema might change over time.
- You need more flexibility in handling objects dynamically.