OPEN SOURCE · MIT

The FHIR server for clinical analytics, written in Rust.

R4 through R6 in one system, complete FHIRPath and SQL-on-FHIR engines, and exports straight to Parquet. Free under MIT.

Get started

Book a call

docker run -p 8080:8080 ghcr.io/heliossoftware/hfs:latest

From the engineers building some of the largest FHIR applications.

A walkthrough of the Helios FHIR Server console, using synthetic patient data.

R4 → R6, one system
100+ FHIRPath functions
5 storage backends
4,300+ commits, MIT

SQL-on-FHIR, built in.

Run ViewDefinitions against live data and export to CSV, JSON, NDJSON, or Parquet. Python bindings included.

View Definitions

Author and manage the ViewDefinitions that SQL on FHIR runs flatten resources with.

VIEW DEFINITIONS⌕ Filter viewsRECENTLY USED

patient_addressesPatient
us_core_blood_pressuresObservation
shareable_patient_demographicsPatient
questionnaire_response_itemsQuestionnaireResponse
patient_names_with_indexPatient

ALL VIEW DEFINITIONS

code_system_hierarchyCodeSystem
condition_flatCondition
encounter_flatEncounter
patient_addressesPatient
patient_and_contact_addressesPatient
patient_demographicsPatient
patient_names_with_indexPatient
questionnaire_response_itemsQuestionnaireResponse
shareable_patient_demographicsPatient
us_core_blood_pressuresObservation

▦ patient_addresses⧉ Duplicate🗑 Delete+ Create New

Definition (JSON)● Runs as you type — results follow the current definitionFormat

2"resourceType": "ViewDefinition",

3"resourceDefinition":

4"http://hl7.org/fhir/uv/sql-on-fhir/StructureDefinition/ViewDefinition",

5"select": [

7"column": [

8{ "path": "getResourceKey()", "name": "patient_id" }

10},

11{

12"forEach": "address",

13"column": [

14{

15"path": "line.join('\n')",

16"name": "street",

17"description": "The full street address."

18},

19{ "path": "use", "name": "use" },

20{ "path": "city", "name": "city" },

21{ "path": "postalCode", "name": "zip" }

22]

23}

24]

25}

CancelSave

⚙ Guided formNo issues.

● Checked as you type: structure, cardinality, required bindings and FHIRPath syntax

ViewDefinition ViewDefinition

id id01a15a1e-93ad-7b13-8ada-a353a1b21574Logical id of this artifact

versionId id1Version specific identifier

lastUpdated instant2026-10-20T16:21:55.758ZWhen the resource version last changed

language codeenLanguage of the resource content

status codegeneratedgenerated | extensions | additional | empty

name stringpatient_addressesName for this view definition (computer friendly)

status codedraftdraft | active | retired | unknown

resource codePatientFHIR resource for the ViewDefinition

Results50 rows · 11 ms

PATIENT_IDSTREETUSECITYZIP

7d24f7a0-6f2e-ce3b-5568-db7b14695583492 Conn ClubhomeEverett02149

44219cdc-80b3-18be-fd67-fbb019971384194 Willms MewshomeArlington02476

44a2f44f-1f46-43ee-8c1f-fd86d4081520386 Watsica Loaf Unit 10homeWestwood02090

06c5e8e3-0e46-d195-bf30-7a5396894b57895 Mosciski CamphomeTyngsboro01879

24531131-f9df-5f7f-7e6f-5630151caeed290 Leffler ForkhomeWaltham02472

627deb5a-b17b-5c08-3bae-bf384381adac107 Mueller CrossroadhomeBoston02210

8a18f5ac-c2e7-6318-a76c-d5ae4f54c13b206 Dare Trailer Unit 8homeCanton02021

73980a37-c279-25bc-7506-fc58b97984fe164 Monahan ValehomeMethuen01841

65c3af91-faec-8df4-7b6d-29f9b6cf3d1e1067 Kiehn Port Suite 12homeCanton02021

c0832d57-9cc4-7178-d8d8-7437f1c312f01032 McKenzie TrafficwayhomeNeedham02494

3b9eadad-d44c-568c-88b4-89cd73a6a33f236 Block Club Unit 44homeTaunton02718

fcc6a489-3d58-c9cc-cc1e-512ef74f5911767 Toy CrossroadworkHull02045

4a76fd03-96e7-9482-4167-be6006ea79b5535 Rippin Underpass Unit 36homeNatick01760

3a04a0d9-a4df-a097-205b-f59044ec1844261 Sauer CrossinghomeEverett02149

f49dd24f-6e78-eb3b-eb47-cd5955babb2d223 Moen Wynd Apt 1homeWorcester01602

aaea74e0-f712-9256-0c69-1618624ef029834 Littel JunctionhomeFall River02721

SQL Exports

0 exports · 0 running

+ New SQL Export

No SQL exports yet. Use New SQL Export to start one.

patient_addressesIn progressCancel⋮

Writing patient_addresses · 0 of 1 subject (1 ViewDefinition) · NDJSON · started 20:37 UTC

‹ SQL Exports

New SQL Export

Run stored view definitions, SQL queries and SQL views as a long-running $sql-export job and download the output files.

NameMonthly patient flat files

What are you exporting?

⛁ Subjects10All▦ View Definitions<> Queries⛁ ViewsFilter subjects

SUBJECTKINDSTATUS

code_system_hierarchyViewDefinitiondraft

condition_flatViewDefinitiondraft

encounter_flatViewDefinitiondraft

patient_addressesViewDefinitiondraft

patient_and_contact_addressesViewDefinitiondraft

patient_demographicsViewDefinitiondraft

patient_names_with_indexViewDefinitiondraft

questionnaire_response_itemsViewDefinitiondraft

shareable_patient_demographicsViewDefinitiondraft

us_core_blood_pressuresViewDefinitiondraft

0 of 10 selected

⇋ Narrow it downoptional — leave empty to export everything

PATIENTS⌕ Search patients

GROUPS⌕ Search groups

SINCEAll time ⌄

CUSTOM INSTANT2026-08-01T00:00:00Z

Output format

NDJSONOne JSON object per row. Streams well into pipelines.

CSVHeader row plus one line per row. Opens in any spreadsheet.

JSONA single JSON array per output. Easiest to inspect by hand.

ParquetColumnar and typed. Best for analytics engines.

› Advanced

⇪ Start Export

A complete FHIRPath engine.

The full FHIRPath 3.0.0 specification, with more than 100 built-in functions.

A native terminology server.

Code systems, value sets, and validation, served from the same platform.

MeSHMedical Subject Headings
v3.Entity Riskv3 Code System Entity Risk
v2.0121v2 RESPONSE FLAG
NarrativeStatusNarrativeStatus

Storage that fits your stack.

SQLite on a laptop, PostgreSQL, Elasticsearch, or MongoDB in production, S3 for scale.

Every FHIR version, one server

Work with R4, R4B, R5, and R6 data in the same application.

Security by standard.

SMART on FHIR authorization, BALP-compliant audit logging, and multi-tenancy.

Tenant Maintenance

Provision, inspect, and delete the tenants this server isolates data between.

TOTAL TENANTS11 registered

RESOURCES STORED13,213,630across all tenants

⌕ Search by name or tenant id…+ Add Tenant

Resources counted at 00:51:08 UTC.

TENANTRESOURCESCREATEDACTIONS

Ddefaultdefault13.21M2026-10-19🗑

D3Department 33department-33Provisioning… this may take a moment.—

Ready for your pipelines.

Bulk Data Export and CDS Hooks, ready for the systems around you.

Subscriptions

Topic-based notifications over rest-hook, WebSocket, and email, the moment a resource changes.

WHAT PEOPLE BUILD

Research-ready datasets with SQL-on-FHIR
Real-time operational dashboards
Data quality checks with FHIRPath
ETL into warehouses and lakes
High-performance FHIR APIs
Research-ready datasets with SQL-on-FHIR
Real-time operational dashboards
Data quality checks with FHIRPath
ETL into warehouses and lakes
High-performance FHIR APIs

Use all of it, or just the parts you need.

The server runs as one system or as components: CLI tools for FHIRPath and SQL-on-FHIR, embeddable libraries, and standalone services. Start with a single binary on a laptop and grow into a production cluster without changing platforms.

CLI toolsEmbeddable librariesStandalone servicesHelios FHIR Server

SQLitePostgresSQLElasticsearchMongoDBS3

IMPLEMENTATION

Run it yourself, or hire the team that wrote it.

Open source

Free under MIT. Run it anywhere, read everything, keep your data model.

View on Github

Built on Helios

Implementation in your environment, EHR and lab integrations, and new clinical applications on the server, from the engineers who wrote it. Support agreements included when you want them.

Book a call

Every line is public. MIT license, 4,300+ commits, issues and roadmap on GitHub.

Give us a star

Join over 2,500 members on our Helios FHIR Server LinkedIn group

Check it out

Up and running in one command

docker run -p 8080:8080 ghcr.io/heliossoftware/hfs:latest

Get started

Book a call

From the engineers behind a SMART on FHIR platform live in more than 2,000 clinics.

Visit the Helios Github

The Helios FHIR Server is an implementation of the HL7® FHIR® standard, built in Rust for high performance and optimized for clinical analytics workloads.

Visit the Github