Aggregate feature flag is contradictory — backend disabled, frontend enable

[GziXnine]

The aggregate router is commented out in the backend (main.py lines 89–96) with a # TEMPORARILY DISABLED comment, but the frontend config has ui.aggregate_enabled: true and there are ~280 lines of client code in src/services/aggregateApi.js that call endpoints which don't exist.

This means a contributor could wire up aggregate UI, watch it fail with 404s, and not understand why.

Current state

Layer	File	Status
Backend import	main.py line 5	# , aggregate — commented out
Backend router	main.py lines 89–96	Entire app.include_router(aggregate.router) block commented out
Backend config	config.yaml → aggregate.enabled	false
Frontend config	config.yaml → ui.aggregate_enabled	true ← contradicts backend
Frontend API client	src/services/aggregateApi.js	280 lines, calls /api/aggregate/...
Frontend hook	src/hooks/useAggregatedData.js	Ready to use
Backend router file	fhir-backend-dynamic/app/routers/aggregate.py	Exists, never loaded
Backend service file	fhir-backend-dynamic/app/services/aggregation.py	Exists, never called

What to do

Pick one of two approaches — don't leave it in this half-state.

Option A: Re-enable behind the existing feature flag

The guard logic is already written — it just needs uncommenting:

# main.py — uncomment line 5:
from app.routers import resources, health, servers, filters, metadata, aggregate

# main.py — uncomment lines 89-96:
if config.aggregate_enabled:
    try:
        app.include_router(aggregate.router, prefix="/api")
        logging.info("Aggregate endpoints enabled successfully")
    except Exception as e:
        logging.error(f"Failed to include aggregate router: {e}")

Then align the config: set ui.aggregate_enabled to match aggregate.enabled (both false by default, both true to test).

If there are runtime errors when enabled, file them as separate issues instead of commenting out the whole feature.

Option B: Mark it experimental explicitly

Move the frontend aggregate files into src/experimental/ so they're clearly separated from production code. Add a note in README.md stating the feature is under development.

References

• FastAPI conditional routers — how include_router is used with feature flags
• Feature flags best practices — Martin Fowler's guide on managing feature toggles (explains why half-enabled states cause problems)