FHIR Extensions Pack
5.3.0 - May 2026 International flag

FHIR Extensions Pack, published by HL7 International / FHIR Infrastructure. This guide is not an authorized publication; it is the continuous build for version 5.3.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-extensions/ and changes regularly. See the Directory of published versions

Extension: Operation Synchronicity Control

Official URL: http://hl7.org/fhir/StructureDefinition/synchronicity-control Version: 5.3.0
Standards status: Trial-use Maturity Level: 3 Computable Name: OperationSynchronicityControl
Other Identifiers: OID:2.16.840.1.113883.4.642.5.1046

Indicates that an operation or interaction must always be handled as synchronous or asynchronous, or that the server must or does provide both, and clients can choose. In R6, use OperationDefinition.synchronicity

Context of Use

This extension may be used on the following element(s)

This extension is allowed for use with FHIR versions R4 to R5 .

Usage info

Usages:

  • This Extension is not used by any profiles in this Implementation Guide

You can also check for usages in the FHIR IG Statistics

Changes since version 5.2.0:

  • New Content

    • Formal Views of Extension Content

    Description of Profiles, Differentials, Snapshots, and how the XML and JSON presentations work.

    This structure is derived from Extension

    Summary

    Simple Extension with the type uri: Indicates that an operation or interaction must always be handled as synchronous or asynchronous, or that the server must or does provide both, and clients can choose. In R6, use OperationDefinition.synchronicity

    Maturity: 3

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
    .. Extension 0..1 Extension synchronous | asynchronous | either
    ... extension 0..0 Extension
    ... url 1..1 uri "http://hl7.org/fhir/StructureDefinition/synchronicity-control"
    ... value[x] 1..1 uri Value of extension
    Binding: OperationSynchronicityControl (required)

    doco Documentation for this format
    NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
    .. Extension 0..1 Extension synchronous | asynchronous | either
    ... id 0..1 id Unique id for inter-element referencing
    ... extension 0..0 Extension
    Slice: Unordered, Open by value:url
    ... url 1..1 uri "http://hl7.org/fhir/StructureDefinition/synchronicity-control"

    doco Documentation for this format

    This structure is derived from Extension

    Summary

    Simple Extension with the type uri: Indicates that an operation or interaction must always be handled as synchronous or asynchronous, or that the server must or does provide both, and clients can choose. In R6, use OperationDefinition.synchronicity

    Maturity: 3

    Differential View

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
    .. Extension 0..1 Extension synchronous | asynchronous | either
    ... extension 0..0 Extension
    ... url 1..1 uri "http://hl7.org/fhir/StructureDefinition/synchronicity-control"
    ... value[x] 1..1 uri Value of extension
    Binding: OperationSynchronicityControl (required)

    doco Documentation for this format

    Snapshot View

    NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
    .. Extension 0..1 Extension synchronous | asynchronous | either
    ... id 0..1 id Unique id for inter-element referencing
    ... extension 0..0 Extension
    Slice: Unordered, Open by value:url
    ... url 1..1 uri "http://hl7.org/fhir/StructureDefinition/synchronicity-control"

    doco Documentation for this format

     

    Other representations of profile: CSV, Excel, Schematron

    Terminology Bindings

    Path Status Usage ValueSet Version Source
    Extension.value[x] Base required Operation Synchronicity Control ValueSet 📦5.3.0 This IG

    Constraints

    Id Grade Path(s) Description Expression
    ele-1 error **ALL** elements All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
    ext-1 error **ALL** extensions Must have either extensions or value[x], not both extension.exists() != value.exists()

    R4B

    The extension is unchanged in R4B

    R4

    The extension is unchanged in R4

    R3

    The extension is unchanged in R3

    Search Parameters for this Extension

    (none found)