SOAP (Simple Object Access Protocol) is an XML-based messaging protocol for exchanging structured information in web services, standardized by W3C as SOAP 1.2 (Second Edition, 2007). It provides a platform-independent, language-neutral framework for web service communication with built-in standards for security (WS-Security), reliable messaging, and transactions.
- SOAP 1.2 Part 1 (Messaging Framework): https://www.w3.org/TR/soap12-part1/
- SOAP 1.2 Part 2 (Adjuncts/HTTP Binding): https://www.w3.org/TR/soap12-part2/
- SOAP 1.1 Note (2000): https://www.w3.org/TR/2000/NOTE-SOAP-20000508/
- W3C XML Protocol Working Group: https://www.w3.org/2000/xp/Group/
A SOAP message consists of:
- Envelope — root element wrapping the entire message
- Header (optional) — metadata and processing directives for SOAP nodes
- Body (required) — the main payload for the ultimate receiver
- Fault — error reporting structure within the Body
| Code | Description |
|---|---|
| VersionMismatch | Unknown SOAP envelope namespace |
| MustUnderstand | Required header block not processed |
| DataEncodingUnknown | Unknown encoding style |
| Sender | Message error caused by the sender |
| Receiver | Processing failure at the receiver |
| Type | File |
|---|---|
| JSON Schema (Envelope) | json-schema/soap-envelope.json |
| JSON Schema (Header) | json-schema/soap-header.json |
| JSON Schema (Header Block) | json-schema/soap-header-block.json |
| JSON Schema (Body) | json-schema/soap-body.json |
| JSON Schema (Fault) | json-schema/soap-fault.json |
| JSON-LD Context | json-ld/soap-context.jsonld |
| JSON Structure | json-structure/soap-envelope-structure.json |
| Vocabulary | vocabulary/soap-vocabulary.yml |
| Examples | examples/soap-envelope-example.json |
- Created: 2025
- Modified: 2026-05-02