Create @fhir.predict() decorator for simplified ML model deployment

[rohan-019]

🧠 Add @fhir.predict() Decorator for Simplified ML Model Deployment

Closes : #143

Summary

This PR introduces a new @fhir.predict() decorator in the BaseFHIRGateway to make deploying machine learning models as FHIR-compliant endpoints simpler and more consistent. It abstracts the boilerplate involved in constructing FHIR resources, letting developers focus purely on model inference logic.

Key Features

• ✅ New decorator: @fhir.predict(resource=RiskAssessment)
• ✅ Automatically wraps raw prediction outputs (float or dict) into FHIR RiskAssessment resources.
• ✅ Supports both sync and async prediction functions.
• ✅ Integrates seamlessly with FastAPI route registration and the existing FHIR gateway pattern.
• ✅ Updates CapabilityStatement to include prediction endpoints.

Implementation Details

• Added prediction handling logic in healthchain/gateway/fhir/base.py:
  • _wrap_prediction() to construct FHIR-compliant resources.
  • Enhanced _execute_handler() to handle async/sync predictions.
  • predict() decorator to register ML endpoints.
• Added comprehensive unit tests in tests/gateway/test_base_fhir_gateway.py.

Example Usage

@fhir.predict(resource=RiskAssessment)
def sepsis_risk(patient_id: str) -> float:
    return 0.85  # High risk

Automatically serves a FHIR endpoint:
GET /predict/RiskAssessment/{id}

Response:

{
  "resourceType": "RiskAssessment",
  "status": "completed",
  "subject": {"reference": "Patient/123"},
  "prediction": [{"probabilityDecimal": 0.85}]
}

Checklist

• I have read the contributing guidelines
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[adamkells]

Hi @rohan-019, just a heads up that you can run the tests and code formatting locally before pushing. There are instructions in the Contributing.md file.

[rohan-019]

Hey, @jenniferjiangkells
please review !!

[rohan-019]

Hi @rohan-019, just a heads up that you can run the tests and code formatting locally before pushing. There are instructions in the Contributing.md file.

Hey @adamkells
Thankyou for your instructions and also it's good things to check the tests and code formatting.
and I have checked tests and formatting.