Infer JSON Schema from a SOAP Response

SOAP Response to JSON Schema

SOAP (Simple Object Access Protocol) is an XML-based messaging protocol still widely used in enterprise applications. Converting SOAP responses to JSON Schema is essential for API migration and integration projects.

Example SOAP Response

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Header>
    <auth:Authentication xmlns:auth="http://example.com/auth">
      <auth:Token>eyJhbGciOiJIUzI1NiJ9</auth:Token>
      <auth:Timestamp>2024-01-01T00:00:00Z</auth:Timestamp>
    </auth:Authentication>
  </soap:Header>
  <soap:Body>
    <ns:GetOrderResponse xmlns:ns="http://example.com/orders">
      <ns:Order>
        <ns:OrderId>12345</ns:OrderId>
        <ns:Status>shipped</ns:Status>
        <ns:Total>99.99</ns:Total>
        <ns:Items>
          <ns:Item>
            <ns:ProductId>A001</ns:ProductId>
            <ns:Quantity>2</ns:Quantity>
            <ns:Price>29.99</ns:Price>
          </ns:Item>
          <ns:Item>
            <ns:ProductId>B002</ns:ProductId>
            <ns:Quantity>1</ns:Quantity>
            <ns:Price>40.01</ns:Price>
          </ns:Item>
        </ns:Items>
      </ns:Order>
    </ns:GetOrderResponse>
  </soap:Body>
</soap:Envelope>

Namespace Handling

The converter preserves namespace prefixes in property names. soap:Envelope, soap:Header, ns:Order all appear as-is in the schema. This is intentional — it maintains a clear mapping between the XML element names and their schema representation.

Schema Structure

The generated schema mirrors the SOAP envelope pattern:

• Envelope → object
  • Header → object (authentication data)
  • Body → object
    • Response → object (business data)
      • Order → object with typed fields
      • Items → array of Item objects

Type Inference in SOAP

SOAP responses often contain strongly typed data:

• OrderId → integer (12345)
• Total → number (99.99)
• Quantity → integer
• Status → string
• Token → string

Migration to REST/JSON

This schema becomes the bridge when migrating from SOAP to REST APIs. You can:

1. Generate the schema from existing SOAP responses
2. Simplify the schema by removing the SOAP envelope layers
3. Use the inner schema as the response schema for your new REST API
4. Validate that the transformation preserves data integrity