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FHIR Infrastructure icon Work Group Maturity Level: 5Trial Use Compartments: N/A

This operation asks the server to check that it implements all the resources, interactions, search parameters, and operations that the client provides in its capability statement. The client provides its capability statement inline, or by referring the server to the canonical URL of its capability statement.

The canonical URL for this operation definition is


Formal Definition (as a OperationDefinition).

URL: [base]/CapabilityStatement/$implements

URL: [base]/CapabilityStatement/[id]/$implements

This is an idempotent operation

In Parameters:

A canonical reference to the server capability statement - use this if the implements is not invoked on an instance (or on the /metadata end-point)


A canonical reference to the client capability statement - use this if the implements is not invoked on an instance (or on the /metadata end-point)


The client capability statement, provided inline

Out Parameters:

Outcome of the CapabilityStatement test

Note: as this is the only out parameter, it is a resource, and it has the name 'return', the result of this operation is returned directly as a resource

The operation does not perform a full conformance check; in particular it does not check that the profiles align. It merely checks that the behaviors the client wishes to use are provided Technically, this operation is implemented as follows:

  • The server's capability statement must have an entry for each resource in the client's capability statement
  • The server's resource support must have matching flags for updateCreate, conditionalCreate, conditionalRead, conditionalUpdate, conditionalPatch, conditionalDelete, searchInclude, searchRevInclude
  • The server's capability statement must have a matching interaction for each interaction in the client capability statement (whether or not it is on a resource)
  • The server's capability statement must have a search parameter with matching name and definition for any search parameters in the client capability statement
  • The server must have an operation definition with a matching reference for any operations in the client capability statement

If the capability statements match by these rules, then the return value is a 200 OK with an operation outcome that contains no issues with severity >= error. If the capability statement doesn't match, the return value is a 4xx error, with an OperationOutcome with at least one issue with severity >= error

Request: Request a CapabilityStatement implements comparison between a client and server systems

POST [base]/CapabilityStatement/$implements
[other headers]

<Parameters xmlns="http://hl7.org/fhir">
    <name value="server"/>
    <valueUri value="http://server.example.org/fhir/metadata"/>
    <name value="client"/>
    <valueUri value="http://client.example.org/fhir/metadata"/>


HTTP/1.1 200 OK
[other headers]

<?xml version="1.0" encoding="UTF-8"?>
<OperationOutcome xmlns="http://hl7.org/fhir">
  <id value="implementsok"/>
    <status value="additional"/>
    <div xmlns="http://www.w3.org/1999/xhtml">
      <p>Server http://server.example.org/fhir/metadata implements client http://client.example.org/fhir/metadata capabilities.</p>
    <severity value="information"/>
    <code value="informational"/>
      <text value="Server http://server.example.org/fhir/metadata implements client http://client.example.org/fhir/metadata capabilities."/>


For more information about operations, including how they are invoked, see Operations.