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Open Client Registry (OpenCR)
What it is
Open Client Registry (OpenCR) links patient identities across information systems to support care coordination, continuity of care, and reporting. It accepts FHIR messages from point-of-service systems such as labs and EMRs, and can assign or look up unique identifiers. Matching is configurable, with probabilistic and deterministic methods and multiple algorithm variations. Users can inspect records in its interface and break matches between records. The documented deployment combines the OpenCR Service and HAPI FHIR Server with OpenSearch or Elasticsearch; OpenHIM is optional. Transaction audit events, including queries, are stored in HAPI FHIR and can be viewed in the interface. OpenCR is open source and supports API, Linux, macOS, self-hosted, web, and Windows environments. It does not contain clinical data or function as a shared health record, and the documented implementation does not let point-of-service systems retrieve patient demographic information. Production setup expects Linux, command-line familiarity, and Linux administration expertise. HAPI FHIR also needs a production database, such as PostgreSQL or MySQL. User authentication solutions such as JWT are not included out of the box.
For and against
For
- Configurable probabilistic and deterministic matching
- Accepts FHIR messages from labs and EMRs
- Users can review and break record matches
- Stores transaction audit events in HAPI FHIR
- Open source and supports self-hosting
Against
- Does not store clinical data
- Point-of-service systems cannot retrieve demographics
- Production deployment requires Linux administration expertise
- User authentication is not provided out of the box
The verdict
OpenCR provides configurable identity matching and record review for organizations connecting information systems. It is not a shared clinical record, and production deployment requires technical expertise and additional database and authentication planning.
Who it suits
OpenCR is intended as a community project for organizations to adapt to their use cases. It may suit teams linking patient identities across systems that have the Linux and command-line skills needed for production deployment.
On the record
- Architecture
- The documented stack includes the OpenCR Service, HAPI FHIR Server, and either OpenSearch or Elasticsearch; OpenHIM is optional.intrahealth.github.io · read 4 Oct 2026
- Auditing
- Transactions, including queries, are stored as audit events in HAPI FHIR and can be viewed in the OpenCR UI.intrahealth.github.io · read 4 Oct 2026
- Authentication limitation
- The documentation says JWT and other user authentication solutions are not provided out of the box and can be added for a deployment.intrahealth.github.io · read 4 Oct 2026
- Data limitation
- OpenCR is not a shared health record and does not contain patient clinical data.intrahealth.github.io · read 4 Oct 2026
- Deployment
- Documentation describes standalone and OpenHIM mediator deployment, and recommends mediator deployment for production use.intrahealth.github.io · read 7 Oct 2026
- History
- IntraHealth International developed OpenCR with USAID support through MEASURE Evaluation, informed by stakeholders in Uganda and technical teams at CDC and USAID.openclientregistry.org · read 7 Oct 2026
- Identifiers and messages
- OpenCR can assign and look up unique identifiers and accept FHIR messages from point-of-service systems such as labs and EMRs.intrahealth.github.io · read 4 Oct 2026
- Installation requirements
- The local installation guide is for demonstrations or tests, not production, and lists a modern CPU with 8GB RAM among its prerequisites.intrahealth.github.io · read 7 Oct 2026
- Integrations
- The documentation describes FHIR R4, HAPI FHIR, OpenHIM, and OpenSearch or Elasticsearch as components or connections in an OpenCR deployment.intrahealth.github.io · read 4 Oct 2026
- Intended users
- The project describes itself as a community project intended for others to adapt to their use cases.intrahealth.github.io · read 7 Oct 2026
- Limits
- The documented implementation does not let point-of-service systems retrieve patient demographic information from the registry, and it does not contain patient clinical data.intrahealth.github.io · read 7 Oct 2026
- Maker
- The About page says OpenCR was developed by IntraHealth International with USAID support through the MEASURE Evaluation project.openclientregistry.org · read 4 Oct 2026
- Manual review
- Its user interface lets users manually correct automatic linkages.openclientregistry.org · read 7 Oct 2026
- Matching
- It supports probabilistic and deterministic matching, configurable decision rules, and 25 algorithm variations.openclientregistry.org · read 7 Oct 2026
- Production storage
- HAPI FHIR requires a database backend in production, with PostgreSQL or MySQL given as examples.intrahealth.github.io · read 4 Oct 2026
- Purpose
- OpenCR links patient identities across information systems to support clinical safety, continuity of care, and accurate reporting.openclientregistry.org · read 7 Oct 2026
- Security
- The documentation says the registry should communicate only with known, trusted clients using TLS certificates, and that standalone mode runs TLS by default and requires signed certificates.intrahealth.github.io · read 7 Oct 2026
- Standards
- OpenCR is open source and open standards-based, and accepts FHIR messages from point-of-service systems such as lab and EMR systems.intrahealth.github.io · read 7 Oct 2026
