CAP Alert Extractor

Point at ANY CAP alerting authority and get structured emergency-alert rows.

This Actor is a generic runner over the OASIS Common Alerting Protocol (CAP) 1.2 — the international standard that national meteorological and emergency-management agencies use to publish public warnings (severe weather, floods, earthquakes, tsunamis, air-quality, civil emergencies). The WMO Register of Alerting Authorities lists ~130 authorities that publish CAP. Give this Actor any of their feeds — or a single CAP document — and get flat, analysis-ready rows. No per-country scraper needed.

Why this is one Actor, not a hundred

Every authority speaks CAP, but they serialize it three different ways on the wire. This Actor auto-detects and decodes all three, so a single input works everywhere:

Serialization	Example authority	What it looks like
GeoJSON	US NWS (api.weather.gov/alerts/active)	one features[] per alert, CAP fields in properties
Inline CAP-XML feed	UN GDACS (gdacs_cap.xml)	an RSS feed where each <item> embeds a full <cap:alert>
Atom/RSS → linked CAP docs	Canada NAAD, PH PAGASA, NZ MetService	a feed whose entries link to standalone CAP XML documents (auto-followed)

It also handles the details the CAP spec leaves to the publisher:

• the cap: namespace prefix is optional and inconsistent — elements are matched by local-name, so <cap:alert>, <alert>, and default-namespaced documents all parse.
• <area> geometry can be a polygon, a circle, or a geocode (SAME / FIPS / UGC) — all three shapes are captured; alerts with only a geocode are fine.
• status: Test / Exercise and msgType: Cancel / Update are real CAP values — the status filter (default Actual) keeps test messages out of your data, and msgType is surfaced so a Cancel is never mistaken for a live warning.
• multi-language alerts (Canadian EN+FR, EU 24-language) emit one row per language.

Input

Field	Type	Default	Description
startUrl	string (required)	—	A CAP feed URL (GeoJSON / CAP-XML / Atom-RSS) or a single CAP XML document URL
mode	enum feed | alert	feed	feed lists current alerts from a feed; alert parses one CAP document
status	enum	Actual	Only emit alerts with this CAP status (empty = any). Keeps Test/Exercise out
severity	enum	(any)	Filter by CAP severity (Extreme / Severe / Moderate / Minor / Unknown)
urgency	enum	(any)	Filter by CAP urgency (Immediate / Expected / Future / Past / Unknown)
certainty	enum	(any)	Filter by CAP certainty (Observed / Likely / Possible / Unlikely / Unknown)
maxRecords	integer	1000	Strict cap: never more than this many rows
userAgent	string	(built-in)	Override the User-Agent (some authorities request a descriptive UA)
timeoutSecs	integer	60	Per-request timeout

Example inputs

{ "startUrl": "https://api.weather.gov/alerts/active", "mode": "feed", "status": "Actual" }

{ "startUrl": "https://www.gdacs.org/xml/gdacs_cap.xml", "mode": "feed", "severity": "Severe" }

{ "startUrl": "https://rss.naad-adna.pelmorex.com/", "mode": "feed" }

{ "startUrl": "https://alerts.metservice.com/cap/rss", "mode": "feed" }

Output

The natural billable row is (alert × info-language × area) — one CAP <alert> with 2 language <info> blocks each covering 7 <area> blocks yields 14 rows. Every row is a flat, fully-nullable superset carrying alert-level fields (identifier, sender, sent, status, msgType, scope, references, incidents), info-level fields (language, categories, event, responseTypes, urgency, severity, certainty, effective, onset, expires, senderName, headline, description, instruction, eventCodes, parameters), and area-level fields (areaDesc, polygons, circles, geocodes, altitude, ceiling), plus provenance (_sourceUrl, _capUrl, _mode, _rowIndex, and the lossless _raw CAP XML when applicable).

{
  "identifier": "urn:oid:2.49.0.1.840...",
  "sender": "w-nws.webmaster@noaa.gov",
  "sent": "2026-07-09T12:26:00-04:00",
  "status": "Actual",
  "msgType": "Update",
  "language": "en-US",
  "event": "Flood Watch",
  "severity": "Severe",
  "urgency": "Future",
  "certainty": "Possible",
  "effective": "2026-07-09T12:26:00-04:00",
  "expires": "2026-07-10T00:00:00-04:00",
  "senderName": "NWS State College PA",
  "headline": "Flood Watch issued July 9 ...",
  "areaDesc": "Perry; Dauphin; Lebanon; Cumberland; Adams; York; Lancaster",
  "geocodes": [{ "valueName": "SAME", "value": "042099" }, { "valueName": "UGC", "value": "PAZ056" }]
}

Honest behavior

• A reachable feed with 0 in-window alerts is a real result (exit 0, zero rows) — not an error.
• If every source is unreachable / unparseable, the Actor fails fast rather than emitting a fabricated empty success, so you can trust a 0-row run.
• It never invents rows and never reports an error as an honest empty.

Pricing

Pay-per-event: $0.0005 per alert record (one alert × info × area row), with a volume discount across subscription tiers.

Maximum charge per run

Each row is billed in the same step that writes it, so you only pay for rows you receive. If you set a maximum total charge on the run, the Actor checks the remaining budget before the feed request and before each linked CAP document request; once one more row is unaffordable it stops and makes no further request to the alerting authority. A budget below one record returns 0 rows without contacting the source. A billing failure stops the run with an error instead of continuing unbilled. If the platform restarts a run, rows already delivered are not written or billed again.

Notes

• Metadata only — the Actor reads the alert content the authority publishes; it does not download any linked binary attachments.
• Discover more authorities and their feed URLs in the WMO Register of Alerting Authorities.