5.5 Implementing a Reusable Transaction

A Transaction Definition is not a standalone specification that repeats the entire framework. Chapter 3 defines the common grammar once. The Transaction Definition specializes that grammar for one Shared Activity. Implementers SHALL therefore apply the Transaction Definition together with Chapter 3 and the endpoint capability requirements in Chapter 4.

Transaction Definition section	Implementation use
1. Transaction Overview — WHY	Confirm that the selected Shared Activity matches the intended exchange.
2. Direct Message and Structured Payload Requirements — WHAT	Apply information-object, Task, human-readable content, Provenance (2.4), and transport requirements.
3. XD Metadata Guidance — HOW	Apply transaction-specific requirements when XD/XDM represents structured payload metadata.
4. FHIR Metadata Guidance — HOW	Apply the same metadata semantics when FHIR represents structured payload metadata.
5. Context IG Guidance	Apply specified Context IG guidance; retain TBD where the definition reserves this section.
6. Technical Actor Functional Requirements — WHO DOES WHAT	Apply Section 6.1 Sender Actor and Section 6.2 Receiver Actor functional and Provenance requirements.
7. Transaction-Specific Processing — WHAT IS SPECIAL	Apply additional transaction-specific rules. Common anomaly handling and workflow status reporting are specified in Chapter 3 and TX8.
8. Relevant Examples	Use illustrative snippets and patterns without depending on versioned whole-sample filenames.