signalk-journey-replay

Replay real published voyage data on any SignalK server. Trips come from a manifest — the default points to Sailing Naturali's journeys at https://sailingnaturali.github.io/journey-data/manifest.json (data repo: sailingnaturali/journey-data). Each trip downloads once, verifies the sha256, caches to disk, and replays its SignalK deltas through the server as if the voyage were happening now. The recorded vessel becomes self on your server; any other vessels in the archive (AIS targets) appear as themselves.

Install

SignalK App Store: search journey replay → install → restart server → enable in Plugin Config.

npm package: @sailingnaturali/signalk-journey-replay

Configuration

| Key | Default | Notes | |-----|---------|-------| | manifestUrl | https://sailingnaturali.github.io/journey-data/manifest.json | Point at any conforming manifest to replay your own journeys. A trip's files.*.url may be relative to this URL (co-locate archives with the manifest) or absolute. | | tripId | — | Select a trip from the dropdown, or type a trip id directly (it's free-text). First start lists the available ids in the plugin status line and caches the manifest, so reopen the config afterward to get the populated dropdown. | | speed | 1 | Pacing divisor: 1 = real-time, 10 = 10× faster, 60 = 60× faster. Inter-delta gaps are divided by this value. Enum: 1, 10, 60. | | loop | false | Restart the trip automatically when it finishes. | | timestampMode | rebase | rebase shifts all timestamps so the trip starts at the current time — keeps time-relative consumers (tide plugins, weather overlays) coherent. original keeps the recorded timestamps, useful for historical analysis. |

How replay behaves

The plugin status line shows download progress (downloading <id> (N%)), then updates every five seconds during playback:

Replaying Boundary Pass, T+00:04 @ 10× — https://youtube.com/...

The YouTube link appears when the manifest entry includes one.

When the trip ends:

finished Boundary Pass: 4821 deltas, 2 malformed

Malformed lines (invalid JSON, missing updates array, unparseable timestamp) are skipped and counted; the replay continues.

The recorded vessel (meta.self in the archive) is mapped to self on your server by dropping the context field — the deltas arrive exactly as if your own instruments produced them. All other contexts (AIS targets) pass through unchanged.

Replayed values carry $source: journey-replay.<original-source> so they are distinguishable from live data on any consuming server.

Coexistence warning

Anything else emitting the same paths — simulators, mock plugins, real sensors — will interleave with the replay. Disable overlapping sources while replaying. Never treat replay output as live navigation data; this is for development, dashboards, and demos.

Offline

If the manifest URL is unreachable the plugin falls back to the last successfully cached copy. Previously downloaded trips replay with no network at all.

Publish your own journeys

Point manifestUrl at any manifest that matches the journey-data schema. The files.deltas entry is required; a self field in the metadata line is recommended so the recorded vessel maps correctly to self on replay.

Full schema, hosting recipe, and gotchas (absolute URLs, self mapping, rebase vs original): Bring your own journey data → journey-data/docs/BRING-YOUR-OWN-DATA.md.

License

MIT