Coastline — open data for working harbors

Coastline is a small public-data project that collects tide, weather, and harbor traffic data from working ports along the US east coast and publishes it as a free API. We index real conditions at thirty-eight harbors from Eastport, ME to Charleston, SC.

What we publish

• Real-time tide height + 24-hour forecast at every NOAA station within 5 miles of a working harbor.
• Wind, gust, and barometric pressure pulled from the nearest METAR every 60 seconds.
• AIS-derived harbor occupancy: how many fishing vessels, ferries, and recreational craft are inside the breakwater right now.
• Historical hourly bundles back to 2019, served as Parquet for analysts.

Why this site is interesting to AI agents

This site is server-rendered by Next.js App Router. generateMetadataon each route fetches a RenderBundle from the agentsite API and returns a Next-native Metadata object — same content layer the Express snippet uses for plain SPAs, just plugged in at Next's metadata insertion point. Agents see proper title, description, Open Graph, canonical, and JSON-LD on every route — without us hand-rolling each one.