FHIR Schema Validator

While all validation features work correctly, we're still integrating FHIR Schema validator into Aidbox.

Test FHIR Schema Validator on public demo page.

This new validation engine is set to replace the existing Zen Schema Validator and JSON Schema validator. The primary objectives for this new validator are enhanced performance, easy configuration, and straightforward interaction. Internally, the new validator utilizes the FHIR Schema for the validation process. We believe that it has the potential to become a community standard, and we are actively working towards this goal. Building on our past experiences, we've simplified the interaction process with the validation module. If you wish to use the StructureDefinition resource as a source of truth, simply POST it.

FHIR Schema

FHIR Schema is a format designed to simplify the implementation and validation of FHIR resources. It is heavily inspired by the design of JSON Schema and introduces a more developer-friendly representation of FHIR StructureDefinitions.

Key features of FHIR Schema include:

  • Simplified Structure FHIR Schema represents FHIR resources and their elements in a more straightforward and intuitive manner compared to FHIR StructureDefinition. Each element is represented as a property of the resource with its type specified directly. This representation is similar to how data structures are typically defined in programming languages.

  • Nested Elements FHIR Schema provides a clear and simple way to represent and validate nested elements in FHIR resources. This is a key requirement for many healthcare data use cases.

  • First-class Arrays Identify and label arrays. Most non-XML implementations distinguish between arrays and singular elements, so it's beneficial to pre-calculate this distinction.

  • Clear Implementation Semantics FHIR Schema offers clear semantics for implementing FHIR validation rules. This clarity can make it easier for developers to create robust and reliable FHIR implementations.

  • Source of metadata This is essential for FHIRPath, CQL, and code-generation.

In summary, FHIR Schema is a format that aims to make FHIR more accessible and easier to work with for developers, potentially leading to improved interoperability of healthcare systems.

Validator Features

Comparison of features with previous validation engines

FeatureFHIR SchemaZen SchemaJSON Schema


Forbidden elements (max 0)

Required elements


Union types

Empty values check

Primitive types


Ordered slicing

Default slice

Type slicing

Binding slicing

Target slicing


Terminology bindings

Extensions validation

Underscore properties


Recursive schemas

Useful pages

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