FHIR and REST

General considerations

FHIR® resources are exchanged using the RESTful paradigm. Each "resource type" has a selection of the same set of interactions defined that can be used to manage the resources in a highly granular fashion. Transactions are performed on the server resource using an HTTP request/response.

Recommended reading, in complement with this implementation guide, is the FHIR RESTful API.

FHIR Version

This guide uses the R5 version of FHIR.

Resource formats

By default FHIR has support for exchanging data both in JSON and XML format. See HL7 FHIR Resource format.

Basepath

All examples in this implementation guide refers to a [base] in the start of an URI/URL. Base is an abbreviation of Service Base URL.

For more information about the basepath see HL7 Service Base URL.

Special operations

OperationDefinition resources are used to define special operations where the search parameters defined for a resource does not cover a specific use case.

Operations can execute on three different levels:

• system level (POST or GET [base]/[operation]),
• resource type level (POST or GET [base]/[resource]/[operation]) or
• instance level (POST or GET [base]/[resource]/[id]/[operation]).

It is specified on each OperationDefinition on what level and what, if any, resource it can be used on.