API and software flows
WSDL and SOAP services as flowcharts
A WSDL file describes a SOAP web service: its operations, messages and endpoints. Like an OpenAPI file, it lists what the service can do but not in which order a process uses it, so combine it with a description of the process to get a flowchart where each automated step names its operation.
What a WSDL file is
WSDL (Web Services Description Language) is an XML format for describing web services, most often SOAP services. WSDL 1.1, the version most commonly found in existing systems, organises a description into:
- types: the data structures, usually as XML Schema,
- messages: the data exchanged,
- portType: the set of operations the service offers,
- binding: how operations are carried (for example SOAP over HTTP),
- service: the network address of the endpoint.
WSDL 2.0 renames some of these concepts (interface instead of portType, endpoint instead of port) but keeps the same idea.
Finding the operations
The operations are the useful part for a flowchart: names such as CreatePolicy, GetQuote or CancelOrder. In WSDL 1.1, look for the operation elements inside portType. Their names usually describe a business action, which makes them good labels for automated steps.
From operations to a process
Operations are a catalogue, not a sequence. The order ("get a quote, then create the policy if the customer accepts") comes from the business process. As with OpenAPI files, the best result comes from combining:
- a short description of the process, naming the owner of each step,
- the WSDL, so that automated steps carry the exact operation name.
Importing a WSDL into Flowchartio
Save the WSDL with an .xml extension (the importer accepts .json, .yaml, .yml and .xml, up to 5 MB). Flowchartio reads the operations and uses them as endpoints during generation, so a step like "Create the policy" can be labelled with CreatePolicy.
What to document for SOAP integrations
- Faults: SOAP faults returned by each operation and how your system reacts.
- Timeouts and retries, with limits, as in any API integration workflow.
- Security steps such as signing or authentication headers, when they affect the flow.
- Hand-offs to people, for example a manual review when the service rejects a request.
Flowchart or BPMN?
Organisations with SOAP services often have BPMN models too. If the goal is to explain the integration to people, a flowchart is enough; if it must run in a process engine, see flowchart vs BPMN.
Turn your process into a flowchart
Describe it in a few sentences. Flowchartio draws the flowchart, then you refine it in conversation.
Generate a flowchart