EncDotNet.S100.DynamicSources.Ais.Drivers.AisStreamIo

IAisMessageSource driver targeting aisstream.io's free WebSocket AIS streaming service.

Packaging: this library is not currently published to NuGet. Consume it via project reference, or through the desktop viewer.

What ships here

Type	Purpose
`AisStreamIoOptions`	API key, endpoint URI, subscribe deadline, reconnect backoff settings.
`IAisStreamIoTransport`	Test seam over `ClientWebSocket`; exchanges JSON text frames.
`ClientWebSocketTransport`	Production transport — wraps `System.Net.WebSockets.ClientWebSocket`, reassembles fragmented frames.
`AisStreamIoMessageSource`	`IAisMessageSource` backed by aisstream.io.
(internal) `AisStreamIoSubscription`	Per-call subscription with automatic reconnect (truncated exponential backoff, 250 ms → 30 s) and swap-and-replace `TryUpdateArea`.
(internal) `AisStreamIoJson`	Hand-rolled JSON contract for `PositionReport` and `ShipStaticData`; sentinel collapse (511 / 360 / 102.3 / -128); API-key redaction for logs.

BCL-only — System.Net.WebSockets.ClientWebSocket plus System.Text.Json. No third-party AIS / WebSocket libraries.

aisstream.io is a BETA service with no published SLA. Treat as best-effort; the driver reconnects transparently on disconnect.
The service requires the subscribe frame within 3 s of connect.
Updating the spatial filter is by resending the subscribe frame on the same socket — TryUpdateArea does this and always returns true.
API keys are sensitive. The driver never logs them — every outgoing frame goes through AisStreamIoJson.RedactApiKey before emission, and a regression test pins this behaviour.