Integration Middleware
Mirth Connect Integration
Mirth Connect (also known as NextGen Connect) is a widely used, open-source healthcare integration engine for routing and transforming messages between systems — most commonly HL7 v2, but also FHIR, XML, and custom formats. It gives engineering teams fine-grained, self-hosted control over interfaces without per-message platform fees. This guide explains how Mirth works, where it fits versus a hosted platform, the setup path, and the compliance considerations.
How Mirth Connect works
Mirth is built around channels. Each channel has a source connector that receives messages (for example, an HL7 v2 feed over MLLP, a file drop, or an HTTP/FHIR endpoint) and one or more destination connectors that send transformed output onward. Between them, transformers — written in JavaScript — let you map, filter, enrich, and reformat messages, including HL7-to-FHIR conversion. This channel-and-transformer model makes Mirth extremely flexible for the messy, point-to-point interface work that dominates real hospital environments.
When to use Mirth
Mirth is a strong fit when you need self-hosted control, want to avoid per-transaction platform costs, or must handle legacy HL7 v2 interfaces that hosted FHIR-first platforms address less directly. The trade-off versus a managed platform like Redox is that you own the infrastructure, monitoring, and maintenance. Teams often use Mirth as the on-the-ground interface engine inside a hospital, complementing — or feeding — cloud FHIR stores and applications further up the stack.
Compliance and operations
Because Mirth is self-hosted, you are responsible for its security and operations: encrypting message channels and storage, controlling access, hardening the server, logging, and ensuring high availability for interfaces that clinicians depend on. Handling Protected Health Information through Mirth means the same HIPAA, UK GDPR, and NHS DSP Toolkit obligations apply. Operational discipline — monitoring channel health, alerting on failures, and managing message persistence — is essential because these interfaces are often mission-critical.
How to integrate with Mirth Connect
- 1
Deploy and secure a Mirth server
Install Mirth Connect on hardened infrastructure with encryption, access control, and reliable storage.
- 2
Define channels for each interface
Create channels with source and destination connectors for the systems and message types you need to connect.
- 3
Write transformers
Use JavaScript transformers to map, filter, and convert messages, including HL7 v2 to FHIR where required.
- 4
Test with representative messages
Validate channels against realistic message samples, covering edge cases and error handling.
- 5
Operate with monitoring and alerting
Run channel monitoring, alerting, and high-availability so mission-critical interfaces stay reliable.
Common use cases
- On-premise HL7 v2 routing between hospital systems
- HL7-to-FHIR conversion feeding modern apps and cloud stores
- Custom point-to-point interfaces a hosted platform doesn't cover cost-effectively
- Lab, radiology, and ADT message integration within a facility
Workflow example
Lab results to a modern app
- An HL7 v2 ORU (results) feed arrives at a Mirth channel over MLLP.
- A transformer maps the message into FHIR Observation and DiagnosticReport resources.
- The destination connector posts the FHIR data to your application or cloud FHIR store.
- Channel monitoring alerts the team if any message fails to process.
Frequently asked questions
Is Mirth Connect free?
Mirth Connect has a long-standing open-source edition that is free to self-host, alongside commercial editions (NextGen Connect) with support and additional features. The open-source engine is widely used in production.
Mirth Connect vs Redox — which should I use?
Mirth gives self-hosted, low-level control and avoids per-transaction fees but you operate it yourself. Redox is a managed platform that reduces operational burden and scales across EHRs. Many architectures use Mirth on-site and a platform or cloud store upstream.
Can Mirth convert HL7 v2 to FHIR?
Yes. Using transformers, Mirth can map HL7 v2 messages into FHIR resources (and vice versa), making it a practical bridge between legacy hospital interfaces and modern FHIR-based applications.
Need a self-hosted interface engine done right? We build and operate Mirth Connect channels and HL7-to-FHIR pipelines. Book a discovery call.