# FHIR® API

We support notifications, queries, and writeback messages with the Redox FHIR API. [Learn more about exchanging data via FHIR](/basics/redox-fhir-api/exchanging-fhir-data).

For technical specs, check out the schemas for:

- [FHIR resources](https://docs.redoxengine.com/permalink/fhir-resources-landing-page) (contains schemas for both queries and writebacks) 

> **FHIR spec examples**
>
> We don't currently recommend copying and pasting examples from our FHIR specs for your API calls. Our specs show the shape and possibility of each FHIR resource; they're not code for real-time API calls. 


- [FHIR notifications](https://docs.redoxengine.com/permalink/fhir-notification-landing-page)

Each schema contains a list of supported interactions and operations for that resource.

## FHIR request URLs

All FHIR request URLs start with this base: `https://api.redoxengine.com/fhir/R4/{{destination-slug}}/{{environment-type}}`. 

> **How to fill out the base URL**
>
> The FHIR base URL tells Redox where to send your message.
>
> - `{{destination-slug]`: Represents your connection. This could be the Redox organization name for your connection.
> _Your Redox implementer provides this value._
> - `{{environment-type}}`: Indicates the type of environment you’re querying or writing data to. Set this to `Development`, `Staging`, or `Production`.

Append the path for the FHIR interaction/operation you want to use to the base URL. For example, to retrieve Patient 123, you could use a URL like: `https://api.redoxengine.com/fhir/R4/redox-fhir-sandbox/Development/Patient/123`. 

> **Case sensitive**
>
> Keep in mind that the request URLs are case sensitive. Environment types and resource names are title case (e..g., `Staging`), but everything else should be lowercase. 

## Download dev tools

Explore Redox APIs with developer test tools.

[Learn more](/how-to-use-redox/use-developer-test-tools)

## Test with the Redox FHIR sandbox

Explore and use Redox FHIR sandbox data to test your integration.

[Learn more](/how-to-use-redox/test-with-redox-fhir-sandbox-data)

## Popular articles

### Redox FHIR API

Learn more about the basics of the Redox FHIR API, including FHIR definitions and Redox capabilities via FHIR.

[Learn more](/basics/redox-fhir-api)

### FHIR glossary

Learn basic definitions of the FHIR interoperability world.

[Learn more](/basics/redox-fhir-api/fhir-glossary)

### Quotas and constraints

Find out technical quotas and constraints for data exchange, including message, file, and rate limits.

[Learn more](/api-reference/quotas-and-constraints)

## Articles in this section

FHIR API resources and notifications.

- [Authenticate an OAuth API key](/api-reference/redox-data-model-api/authenticate-an-oauth-api-key)