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National Events Management Service - FHIR API

Publish and subscribe to patient-centric healthcare event messages with the National Events Management Service (NEMS) - FHIR API.  This national service is implemented on the NHS Spine. 

Overview

Sending System
Sending System
NEMS
NEMS
publish event
publish event
MESH
MESH
send event to all
subscribing systems
send event to all...
Subscribed
System B
Subscribed...
Subscribed
System A
Subscribed...
Subscribed
System C
Subscribed...
manage subscriptions
manage subscriptions
Text is not SVG - cannot display How to publish and subscribe to patient-centric healthcare event messages using NEMS and MESH APIs.

 

Use this API to publish and subscribe to patient-centric healthcare event messages with the National Events Management Service (NEMS).  This national service is implemented on the NHS Spine.

As a sending system, you can:

  • publish an event message

As a subscribing system, you can:

  • create a subscription
  • read a subscription 
  • delete a subscription

This API uses a publish-subscribe model - the sending system publishes specific range of healthcare event messages to National Events Management Service (NEMS), and NEMS forwards the events to all subscribed systems via MESH.

NEMS authorises a specific list of system suppliers and health and social care organisations to publish information as events.

For more details, see the Introduction to the National Events Management Service.


Who can use this

This API can only be used where there is a legal basis to do so.

Make sure you have a valid use case before you go too far with your development. To do this, contact us

For details of the legal basis for sharing NEMS healthcare events, see the NEMS controller catalogue.

You must do this before you can go live (see 'Onboarding' below).



Status

This API is in production.


Service level

This API is a bronze service, meaning it is operational and supported only during business hours (8am to 6pm), Monday to Friday excluding bank holidays.

For more details, see service levels.


Technology

This API is a publish-subscribe event API .

All endpoints use FHIR, specifically FHIR STU3, and:

  • the subscription endpoints use RESTful FHIR 
  • the publish endpoint uses FHIR messaging

To collect events that you have subscribed to, use our MESH API.

The message payload is also FHIR - the same format as used by the sending system.


Network access

This API is available on the internet and on the Health and Social Care Network (HSCN).

For more details see Network access for APIs.


Security and authorisation

This API is application-restricted, meaning the calling application is authenticated but the end user is either not authenticated or not present.

In particular, this API uses TLS-MA authentication.

It also implements authorisation controls which restrict the event types the connecting application can subscribe to or publish.

For more details, see application-restricted APIs.


Environments and testing

NEMS is also available for testing purposes in:

The base URLs are as follows:

Environment Network availability URL
Development HSCN https://msg.dev.spine2.ncrs.nhs.uk/
Integration HSCN https://msg.int.spine2.ncrs.nhs.uk/
Integration Internet https://msg.intspineservices.nhs.uk/
Deployment HSCN https://msg.dep.spine2.ncrs.nhs.uk/
Production HSCN Contact us
Production Internet Contact us

The base URL for the publishing and subscribing interactions are the same, but the path is different, for example:

  • publish in integration over HSCN:
    https://msg.int.spine2.ncrs.nhs.uk/STU3/Events/1/$process-message
  • subscribe in integration over HSCN:
    https://msg.int.spine2.ncrs.nhs.uk/STU3/Subscription
  • publish in integration over the internet:
    https://msg.intspineservices.nhs.uk/STU3/Events/1/$process-message
  • subscribe in integration over the internet:
    https://msg.intspineservices.nhs.uk/STU3/Subscription

There is a testing tool which allows you to simulate a provider publishing event messages. You can also simulate making changes on PDS to trigger PDS-published event messages so you can test event message consumption.

To get advice on how to begin testing, contact us.


Onboarding

You need to get your software approved with us before it can go live with this API. We call this onboarding. The onboarding process can sometimes be quite long, so it’s worth planning well ahead.

As part of this process, you need to demonstrate that you can manage risks and that your software conforms technically with the requirements for this API. This might impact the design of your software. For details, see NEMS FHIR API onboarding support information.

To understand how our online digital onboarding process works, see digital onboarding.

To get started, sign in or create a developer account, then select 'product onboarding'.


Interactions

For a full list of interactions for this API , see Publish an Event Message and Subscriptions Overview.

For details on the general structure of the interactions, see FHIR.

Last edited: 6 March 2025 9:59 am