The fine-dust proxy now resolves natural-language region hints through
city-level station lists and only returns a report when a single station
can be justified. When the hint is ambiguous, the proxy returns a small
candidate list so callers can retry with an exact station name instead
of silently guessing.
The skill guidance was updated to match that runtime contract: region
hint first, then retry with stationName when candidate_stations are
returned. Coordinate-centric guidance was removed from the primary skill
surface so the default path stays lightweight and consistent with the
live proxy behavior.
Constraint: The current AirKorea key can access city-level and station-level measurement APIs but station-info lookups may still return 403
Constraint: Free-API proxy responses must stay safe to expose publicly, so ambiguous locations should not be auto-guessed
Rejected: Auto-pick the first city-level station for unmatched district hints | hides ambiguity and returns misleading air-quality data
Rejected: Keep coordinate-first language in the primary skill | no coordinate source exists in the default user flow
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Preserve the ambiguous_location contract; if you improve matching later, prefer evidence-backed narrowing over silent fallback guesses
Tested: node --test scripts/skill-docs.test.js; npm run test --workspace k-skill-proxy; python3 -m unittest discover -s scripts -p test_fine_dust.py; live curl for ambiguous regionHint=광주 광산구 and exact stationName=우산동(광주)
Not-tested: Broader region alias quality outside the manually checked examples
The fine-dust lane now treats the public proxy as the default surface,
keeps a simple summarized report endpoint, and also exposes a narrow
AirKorea passthrough shape so callers can reuse upstream query patterns
without carrying service keys on the client side.
The skill instructions were trimmed down so the default path is obvious,
region-name guidance stays visible, and detailed implementation notes
move into feature docs instead of bloating the primary skill surface.
Constraint: Free-API proxy endpoints are intentionally public and must avoid embedding upstream secrets in the repo
Constraint: AirKorea station-info access can return 403 even when measurement access succeeds, so the report path needs a measurement-only fallback
Rejected: Keep proxy auth via shared token | contradicts the intended public free-API proxy policy
Rejected: Force all callers onto the summary endpoint only | passthrough compatibility is useful for direct HTTP consumers
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Keep the proxy allowlist narrow; if new upstream routes are exposed, document them explicitly rather than turning this into a generic open proxy
Tested: node --test scripts/skill-docs.test.js; npm run test --workspace k-skill-proxy; python3 -m unittest discover -s scripts -p test_fine_dust.py; live curls against /health, /v1/fine-dust/report, and /B552584/ArpltnInforInqireSvc/getMsrstnAcctoRltmMesureDnsty
Not-tested: Fresh reboot validation of PM2/cloudflared persistence after the latest code-only changes
Jeffrey (Dongkyu) Kim