AISStream (aisstream)

AISStream.io is a free service that streams global real-time AIS (Automatic Identification System) vessel-tracking data over a WebSocket.

Access model, up front:

• WebSocket-only. There is no REST API. The single product surface is a secure WebSocket at wss://stream.aisstream.io/v0/stream.
• Free. The stream is provided at no cost. You obtain a free API key by registering at aisstream.io.
• How it works. Connect, then send one JSON subscription message within 3 seconds. It carries your APIKey, one or more geographic BoundingBoxes, and optional FiltersShipMMSI and FilterMessageTypes. The server then pushes a continuous stream of AIS messages until you close the socket.
• API key placement. The key goes in the APIKey field of the subscription message body - not in an HTTP header.

APIs.json: https://raw.githubusercontent.com/api-evangelist/aisstream/refs/heads/main/apis.yml

Tags

• Vessel Tracking
• AIS
• Maritime
• Ship Tracking
• Real-Time Data
• WebSocket
• Streaming
• Ships
• Maritime Data
• Location

Timestamps

• Created: 2026-07-12
• Modified: 2026-07-12

APIs

AISStream AIS Stream API

Real-time global AIS vessel-tracking stream delivered over a single WebSocket at wss://stream.aisstream.io/v0/stream. The client connects, sends a JSON subscription message (APIKey plus BoundingBoxes and optional FiltersShipMMSI and FilterMessageTypes), and receives a continuous feed of AIS messages - each an envelope with MessageType, a free-form MetaData object, and the decoded Message keyed by its type (PositionReport, ShipStaticData, and the rest of the ITU-R M.1371 message set).

• Human URL: https://aisstream.io/documentation
• Base URL (WebSocket): wss://stream.aisstream.io/v0/stream

Tags

• AIS
• Vessel Tracking
• WebSocket
• Streaming
• Real-Time Data

Properties

• Documentation
• API Reference
• AsyncAPI — AsyncAPI Specification
• Postman Collection — Postman Collection 2.1
• Open Collection — Open Collection 1.0
• Source Code — official AIS message models
• SDK / Examples — example clients in many languages

Subscription message

{
  "APIKey": "<YOUR API KEY>",
  "BoundingBoxes": [[[-90.0, -180.0], [90.0, 180.0]]],
  "FiltersShipMMSI": ["368207620", "367719770"],
  "FilterMessageTypes": ["PositionReport", "ShipStaticData"]
}

Each bounding box is two [latitude, longitude] corner pairs. APIKey and BoundingBoxes are required; FiltersShipMMSI and FilterMessageTypes are optional.

Received message envelope

{
  "MessageType": "PositionReport",
  "MetaData": { "MMSI": 368207620, "ShipName": "EXAMPLE VESSEL", "latitude": 25.702, "longitude": -80.101, "time_utc": "..." },
  "Message": { "PositionReport": { "UserID": 368207620, "Latitude": 25.702, "Longitude": -80.101, "Sog": 12.3, "Cog": 180.5 } }
}

Check MessageType to know which decoded payload is present under Message.

AIS message types

PositionReport, UnknownMessage, AddressedSafetyMessage, AddressedBinaryMessage, AidsToNavigationReport, AssignedModeCommand, BaseStationReport, BinaryAcknowledge, BinaryBroadcastMessage, ChannelManagement, CoordinatedUTCInquiry, DataLinkManagementMessage, DataLinkManagementMessageData, ExtendedClassBPositionReport, GroupAssignmentCommand, GnssBroadcastBinaryMessage, Interrogation, LongRangeAisBroadcastMessage, MultiSlotBinaryMessage, SafetyBroadcastMessage, ShipStaticData, SingleSlotBinaryMessage, StandardClassBPositionReport, StandardSearchAndRescueAircraftReport, StaticDataReport.

Common Properties

• GitHub Organization
• Website
• Documentation
• Plans
• Rate Limits
• Fin Ops

Maintainers

FN: Kin Lane Email: kin@apievangelist.com