io.openwatersPublished by openwaters.ioOfficial publisherv0.18.2Updated Nov 8, 2026
Live AIS vessel positions by MMSI, name, area, or radius, plus coverage. No sign-in, no key.
Read-only MCP access to live AIS vessel positions, tracks, and receiver coverage from the Open Waters network, searchable by area, radius, name, or MMSI.
Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.
Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.
Read https://sourceweft.com/mcp/io.openwaters%2Fais/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.Add this to your client's mcpServers config.
{
"mcpServers": {
"open-waters-ais": {
"type": "http",
"url": "https://ais.openwaters.io/mcp"
}
}
}Live AIS vessel traffic, streamed by bounding box, from community networks, open government feeds, and volunteer receivers. Part of Open Waters. The public instance is ais.openwaters.io. A live map is at openwaters.io/ais/vessels.
This is a beta. There is no SLA. Coverage is uneven. The terms for re-serving some sources are still unsettled (see Coverage). Live status and uptime history are at status.openwaters.io.
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 and use your aiscast token as the APIKey. Existing code keeps working: aisstream-ts, the official Go/Python/JS examples, and 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). Feeder and partner tokens can also follow vessels by IMO number with "imo":[9241061]. You receive one JSON event per decoded AIS message. Each event carries its source, station, receive time, raw sentence, and the decoded fields. Add "snapshot":true to get the last known messages for every vessel already tracked in the subscription first, then live traffic. 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. Each vessel carries its last position, name, type, course, speed, heading, flag, and when and from where aiscast last heard it, plus IMO number, call sign, destination, ETA, draught, length, beam, and the AIS antenna's distances to bow, stern, port, and starboard once its static data has been heard. No token.GET https://ais.openwaters.io/v1/stations: every source aiscast is hearing, with message counts and age.AI assistants. https://ais.openwaters.io/mcp is an MCP (Model Context Protocol) server with six read-only tools: vessels by MMSI, vessels in an area, vessels near a point or another vessel, search by name, a vessel's track, and coverage. No sign-in. Claude lists it in its connector directory. Claude Code: claude mcp add --transport http open-waters-ais https://ais.openwaters.io/mcp. ChatGPT, Cursor, and VS Code take the URL as a custom connector or mcp.json entry; setup for each is on the MCP server page. A token in an Authorization: Bearer header raises the anonymous limits.
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>"}, signed with that key as the API reference shows. The response is your token. It carries the personal tier: 2 streams, 50 messages/s, and 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 [email protected].
Events carry a source, so you can tell a live volunteer receiver from a government feed or an aggregate. synthesized: true marks messages that aiscast re-encoded from a non-NMEA source.
If you run an AIS receiver, send its data here. aiscast re-serves it to everyone, deduplicates it against the open feeds and every other station, and shares volunteer receptions with AISHub as part of our contribution to its community network. Only data received directly by volunteer stations goes to AISHub; public feeds and synthesized messages stay out. You are welcome to keep contributing to other networks too. The terms for contributing are the contributor agreement.
AIS-catcher ... -Q wssmqtt://x:<token>@ais.openwaters.io:443/v1/stream MSGFORMAT NMEA. Each message is sent as it is decoded, over MQTT on the same WebSocket address the JSON stream uses. Your data appears as source: station:<station id>. Name your station on the token page; until you do, it is labeled by the town nearest the traffic it hears. AIS-catcher's HTTP output works too: -H https://ais.openwaters.io/v1/receive USERPWD x:<token> GZIP on INTERVAL 5 posts a batch every five seconds under the same station.-u udp.ais.openwaters.io 10110, docker-shipfeeder with host udp.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. If a sender's !AIVDO sentences identify the vessel, aiscast keys the station by that MMSI instead.udp.ais.openwaters.io:10110 in ais-forwarder (forward AIVDM and AIVDO). Or install the signalk-aiscast plugin. It needs no token. It shares what your receiver hears, and your own position, taken from the transponder or built from Signal K when an AIS transponder is not available. It shows aiscast traffic when you have no receiver.Your station page is https://openwaters.io/ais/stations/<your id>, and the station list links every station. It shows the station's uptime, its messages per hour over the last week, the vessels it heard in the last day by type and how many no other station heard, and the cells it heard over the last week on the map. GET /v1/stations/{id} and /v1/coverage/tiles.json?station=<id> return the same figures. Feeders get the deduplicated raw stream back on wss://ais.openwaters.io/v1/nmea.
AISHub and its contributors make much of our worldwide terrestrial coverage possible. We contribute volunteer receptions in return and credit AISHub on every event from its aggregate.
/v1/stats reports each source's current delay from broadcast to arrival (delay.p50 and delay.p99, in seconds).
Every event names the source it came from. docs/policy.md lists the sources this project leaves out on purpose, and why.
Licensing is per source. aiscast does not relicense the aggregate. aiscast re-serves each event under the terms of the source it came from. That is why source is on every event, every vessel, and every archived hour, and why every /v1 event carries a license tag and an attribution credit line. Every attribution opens with "Open Waters AIS (https://openwaters.io/ais/)"; sources with their own terms add their credit after it. If you display or redistribute the data, display the attribution message included with each event. /v1/vessels carries the same credits as a top-level attribution member on the feature collection, one entry per source present. The table below is the same information as reference.
aiscast's code, including the web client, is AGPL-3.0. The Signal K plugin (signalk-plugin/) stays MIT. Code released before the switch stays available under the MIT license it was released under. Contributors sign the Contributor License Agreement; see CONTRIBUTING.md. The code license covers the software only: the data keeps the per-source terms above. aiscast identifies UDP stations by a keyed hash instead of an address (a station that sends !AIVDO is keyed by that MMSI, and its position is in the data it shares). Station labels on /v1/stations, and near on vessel searches and /v1/vessels/{mmsi}, name the nearest town from GeoNames, CC BY 4.0. The archive keeps raw receptions per source, so the project can purge any source. docs/policy.md states the full position: what the contributor agreement says, the privacy rules, and how the project intends to fund itself without relicensing data.
Developers and operators: see CONTRIBUTING.md.
Source: README.md at commit 579f9f2
Vessels in an area
Vessels currently inside a latitude/longitude bounding box, newest report first, with optional kind and ship-type filters. Anonymous calls may cover 100 square degrees per call.
bboxrequiredflagkindlimittypesVessels near a point or vessel
Vessels within a radius (default 10 NM, maximum 50) of a point or of another vessel's last known position, nearest first, each with distance and bearing from the centre.
latlonflagkindmmsilimittypesradius_nmCoverage and sources
Where Open Waters AIS is hearing AIS right now: sources with their current delay, stations, freshness, and vessel counts. A bounding box adds the stations whose coverage overlaps that area and a count of vessels in it. A station ID adds statistics for that station. Vessel counts cover the last 30 minutes; max_age widens them, to 7d for the last week or all for every vessel the network has heard. An area without reports may have gaps in coverage.
bboxmax_agestationWhere a vessel has been
The positions heard from one vessel over a time range, oldest first, with speed, course, and navigational status. Positions implying an impossible speed for the vessel are left out. A vessel can be identified by MMSI, or by IMO with a feeder or partner token. A call covers up to a year. By default the track is simplified by shape: the positions that hold its path, with breaks where the vessel went unheard; interval_minutes asks for even spacing instead.
toimofrommmsilimitinterval_minutesVessels by MMSI
Last known position and particulars of specific vessels by MMSI (Maritime Mobile Service Identity), or by IMO number with a feeder or partner token: the last report heard for each, however long ago, with destination, ETA, draught, and dimensions once its static data has been heard, and which identifiers match no vessel the network has heard. A vessel whose IMO number has a Wikidata item also carries its type, builder, year built, tonnage, registered dimensions, registry, home port, owner, operator, former names, and Wikipedia and Commons links from there, and a documented US vessel its service type, status, official number, registered dimensions, and tonnage from the US Coast Guard.
imommsiSearch vessels by name
Vessels whose name contains the text, case-insensitive, among every vessel the network has heard, each with its MMSI and last known position when available. An optional bounding box narrows the search. With a feeder or partner token, text of the form IMO 9241061 finds the vessels reporting that IMO number, and a bare seven-digit number finds them ahead of the name matches.
bboxflagnamerequiredlimit100% of the applicable checks met
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.