XML format
WSDL
The machine-readable contract for a SOAP service: operations, messages, bindings and endpoints.
A WSDL is what generates client code for a SOAP service, which makes it the single most consequential document in a SOAP integration. Its types section is usually inline XSD, so a WSDL is really two schema languages in one file.
WSDL 1.1 is a W3C Note, not a Recommendation, and it is what essentially every deployed service uses. WSDL 2.0 changed the namespace and renamed portType to interface, and never achieved adoption.
Constraints that bite
- WSDL 1.1 and 2.0 use different namespaces and different element names.
- The types section is normally inline XSD — validate it as a schema, not just as XML.
- soapAction and the endpoint address are the parts most likely to drift between environments.
- Imported schemas may live at separate URLs; a WSDL alone is often not self-contained.
- Root element
<definitions>- Media type
application/wsdl+xml- Extensions
.wsdl, .xml- Namespaces
http://schemas.xmlsoap.org/wsdl/
- XMLDir label
xml
Specification: WSDL 1.1 note
A minimal valid document
Every example on this site is checked against the same parser the workspace uses, so what you see below is known to be well-formed.
<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://schemas.xmlsoap.org/wsdl/"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="https://example.com/orders">
<message name="GetOrderRequest"/>
<portType name="OrdersPort">
<operation name="GetOrder">
<input message="GetOrderRequest"/>
</operation>
</portType>
</definitions>Namespaces you will meet
WSDL 1.1
http://schemas.xmlsoap.org/wsdl/The service-description namespace for SOAP web services. Still the version almost every deployed WSDL uses.
SOAP 1.1 envelope
http://schemas.xmlsoap.org/soap/envelope/The SOAP 1.1 envelope namespace. Distinct from SOAP 1.2 — the version is encoded in the URI.
XML Schema Definition (XSD)
http://www.w3.org/2001/XMLSchemaThe vocabulary a schema document is written in. Conventionally bound to xs: or xsd:.
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