feat(2-B): add NIFC WFIGS adapters for incidents and perimeters

Two new adapters for wildfire data from NIFC WFIGS:
- wfigs_incidents: Active fire incident locations
- wfigs_perimeters: Active fire perimeter polygons

Features:
- IRWIN GUID dedup via is_published/mark_published
- Fall-off detection with removal events when fires exit current
- Bbox post-filtering with shapely polygon intersection
- Severity mapping from DailyAcres (0-4 scale)
- Subject hierarchy: central.fire.<layer>.<state>.<county>

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/central/adapters/wfigs_common.py

@@ -0,0 +1,211 @@
+"""Shared utilities for WFIGS (Wildland Fire Interagency Geospatial Services) adapters."""
+
+import sqlite3
+from datetime import datetime, timezone
+from typing import Any
+
+# WFIGS FeatureServer endpoints
+WFIGS_INCIDENTS_URL = (
+    "https://services3.arcgis.com/T4QMspbfLg3qTGWY/ArcGIS/rest/services/"
+    "WFIGS_Incident_Locations_Current/FeatureServer/0/query"
+)
+WFIGS_PERIMETERS_URL = (
+    "https://services3.arcgis.com/T4QMspbfLg3qTGWY/ArcGIS/rest/services/"
+    "WFIGS_Interagency_Perimeters_Current/FeatureServer/0/query"
+)
+
+# Fall-off sweep window: 14 days (matches WFIGS's longest fall-off: large fires)
+FALLOFF_WINDOW_DAYS = 14
+
+
+def severity_from_acres(acres: float | None) -> int:
+    """Map DailyAcres to severity level 0-4."""
+    if acres is None or acres == 0:
+        return 0
+    if acres < 10:
+        return 1
+    if acres < 100:
+        return 2
+    if acres < 1000:
+        return 3
+    return 4
+
+
+def parse_wfigs_timestamp(epoch_ms: int | None) -> datetime | None:
+    """Parse WFIGS epoch milliseconds to UTC datetime."""
+    if epoch_ms is None:
+        return None
+    return datetime.fromtimestamp(epoch_ms / 1000, tz=timezone.utc)
+
+
+def build_regions(state: str | None, county: str | None) -> tuple[list[str], str | None]:
+    """
+    Build geo.regions list and primary_region from POOState and POOCounty.
+
+    Returns (regions, primary_region).
+    """
+    if not state:
+        return [], None
+
+    state_upper = state.upper()
+    if county:
+        # Normalize county: remove spaces, uppercase
+        county_normalized = county.replace(" ", "_").upper()
+        region = f"US-{state_upper}-{county_normalized}"
+        return [region], region
+    else:
+        region = f"US-{state_upper}"
+        return [region], region
+
+
+def subject_suffix(state: str | None, county: str | None) -> str:
+    """
+    Build subject suffix from state and county.
+
+    Returns lowercase state.county (county with spaces→underscores).
+    Falls back to "unknown" if state is not available.
+    """
+    if not state:
+        return "unknown"
+
+    state_lower = state.lower()
+    if county:
+        county_lower = county.lower().replace(" ", "_")
+        return f"{state_lower}.{county_lower}"
+    return state_lower
+
+
+def init_observed_table(db: sqlite3.Connection) -> None:
+    """Create the wfigs_observed table if it doesn't exist."""
+    db.execute("""
+        CREATE TABLE IF NOT EXISTS wfigs_observed (
+            layer TEXT NOT NULL,
+            irwin_id TEXT NOT NULL,
+            last_observed_at TEXT NOT NULL,
+            state TEXT,
+            county TEXT,
+            PRIMARY KEY (layer, irwin_id)
+        )
+    """)
+    db.commit()
+
+
+def get_observed_guids(db: sqlite3.Connection, layer: str) -> dict[str, tuple[str, str | None, str | None]]:
+    """
+    Get all observed IRWIN GUIDs for a layer.
+
+    Returns dict mapping irwin_id -> (last_observed_at, state, county).
+    """
+    cursor = db.execute(
+        "SELECT irwin_id, last_observed_at, state, county FROM wfigs_observed WHERE layer = ?",
+        (layer,),
+    )
+    return {row[0]: (row[1], row[2], row[3]) for row in cursor.fetchall()}
+
+
+def update_observed(
+    db: sqlite3.Connection,
+    layer: str,
+    current_guids: dict[str, tuple[str | None, str | None]],
+) -> None:
+    """
+    Update the observed table with current poll's GUIDs.
+
+    current_guids: dict mapping irwin_id -> (state, county)
+    """
+    now_iso = datetime.now(timezone.utc).isoformat()
+
+    # Use INSERT OR REPLACE to upsert
+    for irwin_id, (state, county) in current_guids.items():
+        db.execute(
+            """
+            INSERT OR REPLACE INTO wfigs_observed (layer, irwin_id, last_observed_at, state, county)
+            VALUES (?, ?, ?, ?, ?)
+            """,
+            (layer, irwin_id, now_iso, state, county),
+        )
+    db.commit()
+
+
+def delete_observed(db: sqlite3.Connection, layer: str, irwin_ids: set[str]) -> None:
+    """Delete fallen-off GUIDs from the observed table."""
+    for irwin_id in irwin_ids:
+        db.execute(
+            "DELETE FROM wfigs_observed WHERE layer = ? AND irwin_id = ?",
+            (layer, irwin_id),
+        )
+    db.commit()
+
+
+def cleanup_old_observed(db: sqlite3.Connection, layer: str, days: int = FALLOFF_WINDOW_DAYS) -> None:
+    """Remove observed entries older than the sweep window."""
+    cutoff = datetime.now(timezone.utc).isoformat()
+    db.execute(
+        f"""
+        DELETE FROM wfigs_observed
+        WHERE layer = ?
+        AND datetime(last_observed_at) < datetime(?, '-{days} days')
+        """,
+        (layer, cutoff),
+    )
+    db.commit()
+
+
+def point_in_bbox(
+    lon: float,
+    lat: float,
+    west: float,
+    south: float,
+    east: float,
+    north: float,
+) -> bool:
+    """Check if a point is within a bounding box."""
+    return west <= lon <= east and south <= lat <= north
+
+
+def polygon_intersects_bbox(
+    geometry: dict[str, Any],
+    west: float,
+    south: float,
+    east: float,
+    north: float,
+) -> bool:
+    """
+    Check if a GeoJSON geometry intersects a bounding box.
+
+    Uses shapely for accurate polygon intersection.
+    """
+    try:
+        from shapely.geometry import box, shape
+
+        bbox_polygon = box(west, south, east, north)
+        geom = shape(geometry)
+        return bbox_polygon.intersects(geom)
+    except Exception:
+        # If shapely fails, fall back to centroid check
+        if geometry.get("type") == "Point":
+            coords = geometry.get("coordinates", [])
+            if len(coords) >= 2:
+                return point_in_bbox(coords[0], coords[1], west, south, east, north)
+        return True  # Include if we can't determine
+
+
+def extract_centroid(geometry: dict[str, Any]) -> tuple[float, float] | None:
+    """Extract centroid from GeoJSON geometry."""
+    if not geometry:
+        return None
+
+    geom_type = geometry.get("type")
+    coords = geometry.get("coordinates")
+
+    if geom_type == "Point" and coords and len(coords) >= 2:
+        return (coords[0], coords[1])
+
+    # For polygons, use shapely to compute centroid
+    try:
+        from shapely.geometry import shape
+        geom = shape(geometry)
+        centroid = geom.centroid
+        return (centroid.x, centroid.y)
+    except Exception:
+        return None

src/central/adapters/wfigs_incidents.py

@@ -0,0 +1,373 @@
+"""WFIGS Incidents adapter for wildfire incident locations."""
+
+import logging
+import sqlite3
+from collections.abc import AsyncIterator
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any
+
+import aiohttp
+from pydantic import BaseModel
+from tenacity import (
+    retry,
+    retry_if_exception_type,
+    stop_after_attempt,
+    wait_exponential_jitter,
+)
+
+from central.adapter import SourceAdapter
+from central.adapters.wfigs_common import (
+    WFIGS_INCIDENTS_URL,
+    build_regions,
+    cleanup_old_observed,
+    delete_observed,
+    extract_centroid,
+    get_observed_guids,
+    init_observed_table,
+    parse_wfigs_timestamp,
+    point_in_bbox,
+    severity_from_acres,
+    subject_suffix,
+    update_observed,
+)
+from central.config_models import AdapterConfig, RegionConfig
+from central.config_store import ConfigStore
+from central.models import Event, Geo
+
+logger = logging.getLogger(__name__)
+
+LAYER_NAME = "incidents"
+
+
+class WFIGSIncidentsSettings(BaseModel):
+    """Settings schema for WFIGS Incidents adapter."""
+
+    region: RegionConfig | None = None
+
+
+class WFIGSIncidentsAdapter(SourceAdapter):
+    """NIFC WFIGS wildfire incidents adapter."""
+
+    name = "wfigs_incidents"
+    display_name = "NIFC WFIGS — Wildfire Incidents"
+    description = "Active wildfire incident locations from NIFC WFIGS."
+    settings_schema = WFIGSIncidentsSettings
+    requires_api_key = None
+    api_key_field = None
+    wizard_order = None  # Not in setup wizard
+    default_cadence_s = 300
+
+    def __init__(
+        self,
+        config: AdapterConfig,
+        config_store: ConfigStore,
+        cursor_db_path: Path,
+    ) -> None:
+        self._config_store = config_store
+        self._cursor_db_path = cursor_db_path
+        self._session: aiohttp.ClientSession | None = None
+        self._db: sqlite3.Connection | None = None
+        self._last_poll_time: datetime | None = None
+
+        # Parse region from settings
+        region_dict = config.settings.get("region")
+        if region_dict:
+            self.region: RegionConfig | None = RegionConfig(**region_dict)
+        else:
+            self.region = None
+
+    async def startup(self) -> None:
+        """Initialize HTTP session and SQLite connection."""
+        self._session = aiohttp.ClientSession(
+            timeout=aiohttp.ClientTimeout(total=60),
+        )
+        self._db = sqlite3.connect(self._cursor_db_path)
+
+        # Create tables for dedup and fall-off tracking
+        self._db.execute("""
+            CREATE TABLE IF NOT EXISTS published_ids (
+                adapter TEXT NOT NULL,
+                event_id TEXT NOT NULL,
+                first_seen TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+                last_seen TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+                PRIMARY KEY (adapter, event_id)
+            )
+        """)
+        self._db.execute("""
+            CREATE INDEX IF NOT EXISTS published_ids_last_seen
+            ON published_ids (last_seen)
+        """)
+        init_observed_table(self._db)
+        self._db.commit()
+
+        logger.info(
+            "WFIGS incidents adapter started",
+            extra={"region": self.region.model_dump() if self.region else None},
+        )
+
+    async def shutdown(self) -> None:
+        """Close HTTP session and SQLite connection."""
+        if self._session:
+            await self._session.close()
+            self._session = None
+        if self._db:
+            self._db.close()
+            self._db = None
+        logger.info("WFIGS incidents adapter shut down")
+
+    async def apply_config(self, new_config: AdapterConfig) -> None:
+        """Apply new configuration from hot-reload."""
+        region_dict = new_config.settings.get("region")
+        if region_dict:
+            self.region = RegionConfig(**region_dict)
+        else:
+            self.region = None
+        logger.info(
+            "WFIGS incidents config updated",
+            extra={"region": self.region.model_dump() if self.region else None},
+        )
+
+    def is_published(self, event_id: str) -> bool:
+        """Check if an event has already been published."""
+        if not self._db:
+            return False
+        cur = self._db.execute(
+            "SELECT 1 FROM published_ids WHERE adapter = ? AND event_id = ?",
+            (self.name, event_id),
+        )
+        return cur.fetchone() is not None
+
+    def mark_published(self, event_id: str) -> None:
+        """Mark an event as published."""
+        if not self._db:
+            return
+        self._db.execute(
+            """
+            INSERT INTO published_ids (adapter, event_id, first_seen, last_seen)
+            VALUES (?, ?, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
+            ON CONFLICT (adapter, event_id) DO UPDATE SET
+                last_seen = CURRENT_TIMESTAMP
+            """,
+            (self.name, event_id),
+        )
+        self._db.commit()
+
+    def bump_last_seen(self, event_id: str) -> None:
+        """Bump the last_seen timestamp for an event."""
+        if not self._db:
+            return
+        self._db.execute(
+            "UPDATE published_ids SET last_seen = CURRENT_TIMESTAMP WHERE adapter = ? AND event_id = ?",
+            (self.name, event_id),
+        )
+        self._db.commit()
+
+    def sweep_old_ids(self) -> int:
+        """Remove published_ids older than 14 days. Returns count deleted."""
+        if not self._db:
+            return 0
+        cur = self._db.execute(
+            "DELETE FROM published_ids WHERE adapter = ? AND last_seen < datetime('now', '-14 days')",
+            (self.name,),
+        )
+        self._db.commit()
+        count = cur.rowcount
+        if count > 0:
+            logger.info("WFIGS incidents swept old dedup entries", extra={"count": count})
+        return count
+
+    def subject_for(self, event: Event) -> str:
+        """Compute NATS subject for an event."""
+        # Removal events have a different subject pattern
+        if event.category.startswith("fire.incident.removed"):
+            state = event.data.get("state", "").lower() or "unknown"
+            return f"central.fire.incident.removed.{state}"
+
+        # Regular incidents: central.fire.incident.<state>.<county>
+        state = event.data.get("POOState")
+        county = event.data.get("POOCounty")
+        suffix = subject_suffix(state, county)
+        return f"central.fire.incident.{suffix}"
+
+    @retry(
+        stop=stop_after_attempt(3),
+        wait=wait_exponential_jitter(initial=1, max=30),
+        retry=retry_if_exception_type((aiohttp.ClientError, TimeoutError)),
+    )
+    async def _fetch_features(self) -> list[dict[str, Any]]:
+        """Fetch features from WFIGS FeatureServer."""
+        if not self._session:
+            raise RuntimeError("Session not initialized")
+
+        # Build query params
+        params: dict[str, str] = {
+            "outFields": "*",
+            "returnGeometry": "true",
+            "f": "geojson",
+        }
+
+        # Time filter: only fetch modified since last poll
+        if self._last_poll_time:
+            iso_time = self._last_poll_time.strftime("%Y-%m-%d %H:%M:%S")
+            params["where"] = f"ModifiedOnDateTime > timestamp '{iso_time}'"
+        else:
+            params["where"] = "1=1"
+
+        # Bbox filter if region configured
+        if self.region:
+            bbox = f"{self.region.west},{self.region.south},{self.region.east},{self.region.north}"
+            params["geometry"] = bbox
+            params["geometryType"] = "esriGeometryEnvelope"
+            params["spatialRel"] = "esriSpatialRelIntersects"
+            params["inSR"] = "4326"
+
+        async with self._session.get(WFIGS_INCIDENTS_URL, params=params) as resp:
+            resp.raise_for_status()
+            data = await resp.json()
+
+        features = data.get("features", [])
+        logger.info(
+            "WFIGS incidents fetch completed",
+            extra={"feature_count": len(features)},
+        )
+        return features
+
+    async def poll(self) -> AsyncIterator[Event]:
+        """Poll WFIGS for incident updates."""
+        if not self._db:
+            raise RuntimeError("Database not initialized")
+
+        # Fetch features from upstream
+        try:
+            features = await self._fetch_features()
+        except Exception as e:
+            logger.error("WFIGS incidents fetch failed", extra={"error": str(e)})
+            raise
+
+        # Get previous poll's observed GUIDs for fall-off detection
+        observed_before = get_observed_guids(self._db, LAYER_NAME)
+
+        # Process features and track current GUIDs
+        current_guids: dict[str, tuple[str | None, str | None]] = {}
+        events_yielded = 0
+
+        for feature in features:
+            props = feature.get("properties", {})
+            geometry = feature.get("geometry")
+
+            irwin_id = props.get("IrwinID")
+            if not irwin_id:
+                continue
+
+            # Extract location
+            centroid = extract_centroid(geometry)
+
+            # Post-filter: skip if outside region bbox
+            if self.region and centroid:
+                lon, lat = centroid
+                if not point_in_bbox(
+                    lon, lat,
+                    self.region.west, self.region.south,
+                    self.region.east, self.region.north,
+                ):
+                    continue
+
+            # Track this GUID as observed (for fall-off detection)
+            state = props.get("POOState")
+            county = props.get("POOCounty")
+            current_guids[irwin_id] = (state, county)
+
+            # Parse fields
+            incident_type = props.get("IncidentTypeCategory", "unknown").lower()
+            discovery_time = parse_wfigs_timestamp(props.get("FireDiscoveryDateTime"))
+            daily_acres = props.get("DailyAcres")
+
+            # Build regions
+            regions, primary_region = build_regions(state, county)
+
+            # Build geo
+            if centroid:
+                geo = Geo(
+                    centroid=centroid,
+                    bbox=(centroid[0], centroid[1], centroid[0], centroid[1]),
+                    regions=regions,
+                    primary_region=primary_region,
+                )
+            else:
+                geo = Geo(regions=regions, primary_region=primary_region)
+
+            # Build event
+            event = Event(
+                id=irwin_id,
+                adapter=self.name,
+                category=f"fire.incident.{incident_type}",
+                time=discovery_time or datetime.now(timezone.utc),
+                severity=severity_from_acres(daily_acres),
+                geo=geo,
+                data={
+                    "IrwinID": irwin_id,
+                    "IncidentName": props.get("IncidentName"),
+                    "IncidentTypeCategory": props.get("IncidentTypeCategory"),
+                    "DailyAcres": daily_acres,
+                    "PercentContained": props.get("PercentContained"),
+                    "FireDiscoveryDateTime": props.get("FireDiscoveryDateTime"),
+                    "ModifiedOnDateTime": props.get("ModifiedOnDateTime"),
+                    "POOState": state,
+                    "POOCounty": county,
+                    "raw": props,
+                },
+            )
+
+            yield event
+            events_yielded += 1
+
+        # Detect fall-offs: GUIDs in previous but not current
+        fallen_off = set(observed_before.keys()) - set(current_guids.keys())
+
+        for irwin_id in fallen_off:
+            last_observed, state, county = observed_before[irwin_id]
+            now = datetime.now(timezone.utc)
+
+            removal_event = Event(
+                id=f"{irwin_id}:removed:{now.isoformat()}",
+                adapter=self.name,
+                category="fire.incident.removed",
+                time=now,
+                severity=0,
+                geo=Geo(),
+                data={
+                    "irwin_id": irwin_id,
+                    "last_observed_at": last_observed,
+                    "state": state,
+                    "county": county,
+                    "reason": "fallen_off_current_service",
+                },
+            )
+
+            yield removal_event
+            events_yielded += 1
+            logger.info(
+                "WFIGS incident fall-off detected",
+                extra={"irwin_id": irwin_id, "state": state},
+            )
+
+        # Update observed table
+        update_observed(self._db, LAYER_NAME, current_guids)
+        delete_observed(self._db, LAYER_NAME, fallen_off)
+
+        # Periodic cleanup of old entries
+        cleanup_old_observed(self._db, LAYER_NAME)
+        self.sweep_old_ids()
+
+        # Update last poll time
+        self._last_poll_time = datetime.now(timezone.utc)
+
+        logger.info(
+            "WFIGS incidents poll completed",
+            extra={
+                "events_yielded": events_yielded,
+                "current_observed": len(current_guids),
+                "fallen_off": len(fallen_off),
+            },
+        )

src/central/adapters/wfigs_perimeters.py

@@ -0,0 +1,387 @@
+"""WFIGS Perimeters adapter for wildfire perimeter polygons."""
+
+import logging
+import sqlite3
+from collections.abc import AsyncIterator
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any
+
+import aiohttp
+from pydantic import BaseModel
+from tenacity import (
+    retry,
+    retry_if_exception_type,
+    stop_after_attempt,
+    wait_exponential_jitter,
+)
+
+from central.adapter import SourceAdapter
+from central.adapters.wfigs_common import (
+    WFIGS_PERIMETERS_URL,
+    build_regions,
+    cleanup_old_observed,
+    delete_observed,
+    extract_centroid,
+    get_observed_guids,
+    init_observed_table,
+    parse_wfigs_timestamp,
+    polygon_intersects_bbox,
+    severity_from_acres,
+    subject_suffix,
+    update_observed,
+)
+from central.config_models import AdapterConfig, RegionConfig
+from central.config_store import ConfigStore
+from central.models import Event, Geo
+
+logger = logging.getLogger(__name__)
+
+LAYER_NAME = "perimeters"
+
+
+class WFIGSPerimetersSettings(BaseModel):
+    """Settings schema for WFIGS Perimeters adapter."""
+
+    region: RegionConfig | None = None
+
+
+class WFIGSPerimetersAdapter(SourceAdapter):
+    """NIFC WFIGS wildfire perimeters adapter."""
+
+    name = "wfigs_perimeters"
+    display_name = "NIFC WFIGS — Wildfire Perimeters"
+    description = "Active wildfire perimeter polygons from NIFC WFIGS."
+    settings_schema = WFIGSPerimetersSettings
+    requires_api_key = None
+    api_key_field = None
+    wizard_order = None  # Not in setup wizard
+    default_cadence_s = 300
+
+    def __init__(
+        self,
+        config: AdapterConfig,
+        config_store: ConfigStore,
+        cursor_db_path: Path,
+    ) -> None:
+        self._config_store = config_store
+        self._cursor_db_path = cursor_db_path
+        self._session: aiohttp.ClientSession | None = None
+        self._db: sqlite3.Connection | None = None
+        self._last_poll_time: datetime | None = None
+
+        # Parse region from settings
+        region_dict = config.settings.get("region")
+        if region_dict:
+            self.region: RegionConfig | None = RegionConfig(**region_dict)
+        else:
+            self.region = None
+
+    async def startup(self) -> None:
+        """Initialize HTTP session and SQLite connection."""
+        self._session = aiohttp.ClientSession(
+            timeout=aiohttp.ClientTimeout(total=120),  # Longer timeout for large polygons
+        )
+        self._db = sqlite3.connect(self._cursor_db_path)
+
+        # Create tables for dedup and fall-off tracking
+        self._db.execute("""
+            CREATE TABLE IF NOT EXISTS published_ids (
+                adapter TEXT NOT NULL,
+                event_id TEXT NOT NULL,
+                first_seen TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+                last_seen TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+                PRIMARY KEY (adapter, event_id)
+            )
+        """)
+        self._db.execute("""
+            CREATE INDEX IF NOT EXISTS published_ids_last_seen
+            ON published_ids (last_seen)
+        """)
+        init_observed_table(self._db)
+        self._db.commit()
+
+        logger.info(
+            "WFIGS perimeters adapter started",
+            extra={"region": self.region.model_dump() if self.region else None},
+        )
+
+    async def shutdown(self) -> None:
+        """Close HTTP session and SQLite connection."""
+        if self._session:
+            await self._session.close()
+            self._session = None
+        if self._db:
+            self._db.close()
+            self._db = None
+        logger.info("WFIGS perimeters adapter shut down")
+
+    async def apply_config(self, new_config: AdapterConfig) -> None:
+        """Apply new configuration from hot-reload."""
+        region_dict = new_config.settings.get("region")
+        if region_dict:
+            self.region = RegionConfig(**region_dict)
+        else:
+            self.region = None
+        logger.info(
+            "WFIGS perimeters config updated",
+            extra={"region": self.region.model_dump() if self.region else None},
+        )
+
+    def is_published(self, event_id: str) -> bool:
+        """Check if an event has already been published."""
+        if not self._db:
+            return False
+        cur = self._db.execute(
+            "SELECT 1 FROM published_ids WHERE adapter = ? AND event_id = ?",
+            (self.name, event_id),
+        )
+        return cur.fetchone() is not None
+
+    def mark_published(self, event_id: str) -> None:
+        """Mark an event as published."""
+        if not self._db:
+            return
+        self._db.execute(
+            """
+            INSERT INTO published_ids (adapter, event_id, first_seen, last_seen)
+            VALUES (?, ?, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
+            ON CONFLICT (adapter, event_id) DO UPDATE SET
+                last_seen = CURRENT_TIMESTAMP
+            """,
+            (self.name, event_id),
+        )
+        self._db.commit()
+
+    def bump_last_seen(self, event_id: str) -> None:
+        """Bump the last_seen timestamp for an event."""
+        if not self._db:
+            return
+        self._db.execute(
+            "UPDATE published_ids SET last_seen = CURRENT_TIMESTAMP WHERE adapter = ? AND event_id = ?",
+            (self.name, event_id),
+        )
+        self._db.commit()
+
+    def sweep_old_ids(self) -> int:
+        """Remove published_ids older than 14 days. Returns count deleted."""
+        if not self._db:
+            return 0
+        cur = self._db.execute(
+            "DELETE FROM published_ids WHERE adapter = ? AND last_seen < datetime('now', '-14 days')",
+            (self.name,),
+        )
+        self._db.commit()
+        count = cur.rowcount
+        if count > 0:
+            logger.info("WFIGS perimeters swept old dedup entries", extra={"count": count})
+        return count
+
+    def subject_for(self, event: Event) -> str:
+        """Compute NATS subject for an event."""
+        # Removal events have a different subject pattern
+        if event.category.startswith("fire.perimeter.removed"):
+            state = event.data.get("state", "").lower() or "unknown"
+            return f"central.fire.perimeter.removed.{state}"
+
+        # Regular perimeters: central.fire.perimeter.<state>.<county>
+        state = event.data.get("POOState")
+        county = event.data.get("POOCounty")
+        suffix = subject_suffix(state, county)
+        return f"central.fire.perimeter.{suffix}"
+
+    @retry(
+        stop=stop_after_attempt(3),
+        wait=wait_exponential_jitter(initial=1, max=30),
+        retry=retry_if_exception_type((aiohttp.ClientError, TimeoutError)),
+    )
+    async def _fetch_features(self) -> list[dict[str, Any]]:
+        """Fetch features from WFIGS FeatureServer."""
+        if not self._session:
+            raise RuntimeError("Session not initialized")
+
+        # Build query params
+        params: dict[str, str] = {
+            "outFields": "*",
+            "returnGeometry": "true",
+            "f": "geojson",
+        }
+
+        # Time filter: only fetch modified since last poll
+        # Note: perimeters use attr_ModifiedOnDateTime_dt field
+        if self._last_poll_time:
+            iso_time = self._last_poll_time.strftime("%Y-%m-%d %H:%M:%S")
+            params["where"] = f"attr_ModifiedOnDateTime_dt > timestamp '{iso_time}'"
+        else:
+            params["where"] = "1=1"
+
+        # Bbox filter if region configured
+        if self.region:
+            bbox = f"{self.region.west},{self.region.south},{self.region.east},{self.region.north}"
+            params["geometry"] = bbox
+            params["geometryType"] = "esriGeometryEnvelope"
+            params["spatialRel"] = "esriSpatialRelIntersects"
+            params["inSR"] = "4326"
+
+        async with self._session.get(WFIGS_PERIMETERS_URL, params=params) as resp:
+            resp.raise_for_status()
+            data = await resp.json()
+
+        features = data.get("features", [])
+        logger.info(
+            "WFIGS perimeters fetch completed",
+            extra={"feature_count": len(features)},
+        )
+        return features
+
+    async def poll(self) -> AsyncIterator[Event]:
+        """Poll WFIGS for perimeter updates."""
+        if not self._db:
+            raise RuntimeError("Database not initialized")
+
+        # Fetch features from upstream
+        try:
+            features = await self._fetch_features()
+        except Exception as e:
+            logger.error("WFIGS perimeters fetch failed", extra={"error": str(e)})
+            raise
+
+        # Get previous poll's observed GUIDs for fall-off detection
+        observed_before = get_observed_guids(self._db, LAYER_NAME)
+
+        # Process features and track current GUIDs
+        current_guids: dict[str, tuple[str | None, str | None]] = {}
+        events_yielded = 0
+
+        for feature in features:
+            props = feature.get("properties", {})
+            geometry = feature.get("geometry")
+
+            # WFIGS Perimeters use prefixed field names (attr_*, poly_*)
+            irwin_id = props.get("attr_IrwinID") or props.get("poly_IRWINID")
+            if not irwin_id:
+                continue
+
+            # Post-filter: skip if geometry doesn't intersect region bbox
+            if self.region and geometry:
+                if not polygon_intersects_bbox(
+                    geometry,
+                    self.region.west, self.region.south,
+                    self.region.east, self.region.north,
+                ):
+                    continue
+
+            # Track this GUID as observed (for fall-off detection)
+            state = props.get("attr_POOState")
+            county = props.get("attr_POOCounty")
+            current_guids[irwin_id] = (state, county)
+
+            # Parse fields using prefixed names
+            incident_type = props.get("attr_IncidentTypeCategory", "unknown").lower()
+            discovery_time = parse_wfigs_timestamp(props.get("attr_FireDiscoveryDateTime"))
+            # Use poly_GISAcres or attr_IncidentSize for acreage
+            daily_acres = props.get("attr_IncidentSize") or props.get("poly_GISAcres")
+
+            # Build regions
+            regions, primary_region = build_regions(state, county)
+
+            # Extract centroid for geo
+            centroid = extract_centroid(geometry)
+
+            # Build bbox from geometry if available
+            bbox = None
+            if geometry:
+                try:
+                    from shapely.geometry import shape
+                    geom = shape(geometry)
+                    bounds = geom.bounds  # (minx, miny, maxx, maxy)
+                    bbox = (bounds[0], bounds[1], bounds[2], bounds[3])
+                except Exception:
+                    if centroid:
+                        bbox = (centroid[0], centroid[1], centroid[0], centroid[1])
+
+            # Build geo
+            geo = Geo(
+                centroid=centroid,
+                bbox=bbox,
+                regions=regions,
+                primary_region=primary_region,
+            )
+
+            # Build event with geometry in data
+            # Use normalized field names in event data for consistency
+            event = Event(
+                id=irwin_id,
+                adapter=self.name,
+                category=f"fire.perimeter.{incident_type}",
+                time=discovery_time or datetime.now(timezone.utc),
+                severity=severity_from_acres(daily_acres),
+                geo=geo,
+                data={
+                    "IrwinID": irwin_id,
+                    "IncidentName": props.get("attr_IncidentName") or props.get("poly_IncidentName"),
+                    "IncidentTypeCategory": props.get("attr_IncidentTypeCategory"),
+                    "DailyAcres": props.get("attr_IncidentSize"),
+                    "GISAcres": props.get("poly_GISAcres"),
+                    "PercentContained": props.get("attr_PercentContained"),
+                    "FireDiscoveryDateTime": props.get("attr_FireDiscoveryDateTime"),
+                    "ModifiedOnDateTime": props.get("attr_ModifiedOnDateTime_dt"),
+                    "POOState": state,
+                    "POOCounty": county,
+                    "geometry": geometry,  # Full GeoJSON polygon
+                    "raw": props,
+                },
+            )
+
+            yield event
+            events_yielded += 1
+
+        # Detect fall-offs: GUIDs in previous but not current
+        fallen_off = set(observed_before.keys()) - set(current_guids.keys())
+
+        for irwin_id in fallen_off:
+            last_observed, state, county = observed_before[irwin_id]
+            now = datetime.now(timezone.utc)
+
+            removal_event = Event(
+                id=f"{irwin_id}:removed:{now.isoformat()}",
+                adapter=self.name,
+                category="fire.perimeter.removed",
+                time=now,
+                severity=0,
+                geo=Geo(),
+                data={
+                    "irwin_id": irwin_id,
+                    "last_observed_at": last_observed,
+                    "state": state,
+                    "county": county,
+                    "reason": "fallen_off_current_service",
+                },
+            )
+
+            yield removal_event
+            events_yielded += 1
+            logger.info(
+                "WFIGS perimeter fall-off detected",
+                extra={"irwin_id": irwin_id, "state": state},
+            )
+
+        # Update observed table
+        update_observed(self._db, LAYER_NAME, current_guids)
+        delete_observed(self._db, LAYER_NAME, fallen_off)
+
+        # Periodic cleanup of old entries
+        cleanup_old_observed(self._db, LAYER_NAME)
+        self.sweep_old_ids()
+
+        # Update last poll time
+        self._last_poll_time = datetime.now(timezone.utc)
+
+        logger.info(
+            "WFIGS perimeters poll completed",
+            extra={
+                "events_yielded": events_yielded,
+                "current_observed": len(current_guids),
+                "fallen_off": len(fallen_off),
+            },
+        )