aiscast

Live AIS vessel traffic, streamed by bounding box, from open government feeds and volunteer receivers. Part of Open Waters. The public instance is ais.openwaters.io; a live map is at openwatersio.github.io/aiscast.

This is a beta. No SLA, coverage is uneven, and the terms under which some sources are re-served are still being settled (see Coverage). Live status and uptime history: status.openwaters.io.

Usage

aisstream.io clients. aiscast speaks aisstream.io's protocol on wss://ais.openwaters.io/v0/stream: the same subscribe message, the same MessageType / MetaData / Message frames. Change the hostname, use your aiscast token as the APIKey, and existing code keeps working (aisstream-ts, the official Go/Python/JS examples, signalk-aisstream).

Native API (full reference).

• wss://ais.openwaters.io/v1/stream: send {"type":"subscribe","bbox":[[minLat,minLon,maxLat,maxLon]]} or {"type":"subscribe","mmsi":[368168720]} (or both) and receive one JSON event per decoded AIS message with its source, station, receive time, raw sentence, and the decoded fields. Subscribing needs no token.
• GET https://ais.openwaters.io/v1/vessels?bbox=minLat,minLon,maxLat,maxLon (or ?mmsi=a,b,c): GeoJSON of every vessel currently in view (last position, name, type, course, speed, heading, when and from where it was last heard). No token.
• GET https://ais.openwaters.io/v1/stations: every source aiscast is hearing, with message counts and age.

Tokens. /v0/stream needs a token. A personal token is self-serve and never expires: use the token page, or generate an Ed25519 keypair and POST https://ais.openwaters.io/v1/keys with {"pubkey":"<base64url public key>"}; the response is your token. It carries the personal tier (2 streams, 50 messages/s, a 20°×20° area); feed data from the same token and it becomes a feeder token by itself. Tiers and limits are in docs/limits.md; for more than the feeder tier, or for commercial use, write to hello@openwaters.io.

Events carry a source so you can tell a live volunteer receiver from a government feed or an aggregate, and synthesized: true marks messages that were re-encoded from a non-NMEA source.

Contributing data

If you run an AIS receiver, send it here and it is re-served to everyone, deduplicated against the open feeds and every other station, and forwarded to AISHub as part of our reciprocal feed (only volunteer receptions go there; public feeds are never relayed, per their terms). Volunteer terms proper come with the next stage; until then treat this as a beta in both directions.

• AIS-catcher (preferred: authenticated HTTP, works behind any NAT): get a token at openwatersio.github.io/aiscast/token.html (one click, stays in your browser), then AIS-catcher ... -H https://ais.openwaters.io/v1/receive USERPWD x:<token> GZIP on INTERVAL 15. Your data appears as source: http:<station id>. Named stations with higher limits: ask.
• UDP (no token): AIS-catcher -u ais.openwaters.io 10110, docker-shipfeeder with host ais.openwaters.io port 10110, or any NMEA forwarder sending plain !AIVDM / !AIVDO sentences (TAG blocks welcome). Your station appears as udp:<id>, a keyed hash of your address, never the address itself; a sender whose !AIVDO sentences identify the vessel is keyed by that MMSI instead.
• Signal K: add a UDP target ais.openwaters.io:10110 in ais-forwarder (forward AIVDM and AIVDO). Or install the signalk-aiscast plugin: no token to paste, shares what your receiver hears (and your own position), and shows aiscast traffic when you have no receiver.

Your station page is the map with ?station=<your id>: vessels heard, coverage extent, message counts, how many were heard elsewhere first; the same numbers are at GET /v1/stations/{id}. Feeders get the deduplicated raw stream back on wss://ais.openwaters.io/v1/nmea.

Coverage

Source	Where	Freshness
Kystverket	Norwegian coast, 40–60 nm out	live
Fintraffic Digitraffic	Finnish waters	live
Volunteer receivers	wherever they are (Buzzards Bay / Vineyard Sound as of the first station)	live
AISHub aggregate	worldwide terrestrial, ~50k vessels	1–6 min (their snapshot refreshes every ~5 min)
aisstream.io	worldwide, when it is up	live; frequently down

Every event says which of these it came from. What is deliberately not pulled in, and why, is in PLAN.md.

Licensing and attribution

Licensing is per source. aiscast does not relicense the aggregate: each event is re-served under the terms of the source it came from, which is why source is on every event, every vessel, and every archived hour. If you display or redistribute the data, carry the source's attribution through.

Source	License	What you must do
Kystverket	NLOD 2.0	Credit: "Contains data under the Norwegian licence for Open Government data (NLOD) distributed by the Norwegian Coastal Administration." NLOD is not sublicensable: you are bound by it directly.
Fintraffic Digitraffic	CC BY 4.0	Credit: "Source: Fintraffic / digitraffic.fi, license CC 4.0 BY."
Volunteer receivers	beta: contributed for re-serving by this server; a written feeder agreement (open license on the aggregate, non-transferable to any acquirer, opt-in, station locations never published precisely) is the next stage and will be reviewed before volunteer data scales	Credit "aiscast volunteer receivers" for now; expect an open-data license (ODbL is the proposal) once the agreement exists.
AISHub aggregate	AISHub membership; their published terms grant "use" only	Treat as view-only: fine to display, do not build a product on these events alone. They may be withdrawn; source: aishub and the aishub-terms/ archive tag make that a clean cut.
aisstream.io	no published terms	Same as AISHub: best effort, may disappear. source: aisstream.

aiscast's own code is MIT. Volunteer station locations are never published with precision, UDP stations are identified by a keyed hash rather than an address, and the archive keeps raw receptions per source so any source can be purged. The full position, including the feeder agreement draft, the privacy rules, and how the project intends to fund itself without relicensing data, is in PLAN.md.

Contributing

Developers and operators: see CONTRIBUTING.md.