sailing-mcp

sailing-mcp

A remote MCP server for sailing navigation. It gives an AI assistant (Claude Desktop, Claude.ai, Claude Code, or any MCP client) a set of tools for wind & wave forecasts, tides, tidal currents, marinas, bridge schedules and live AIS vessel traffic — with a strong focus on Dutch / North Sea waters.

It is stateless and multi-tenant by design: every user passes their own provider API keys in the MCP URL, so a single deployment can serve many people without storing anyone's credentials. Tools that need a key only appear in the tool list when that key is present.

Tools

Tool	Source	Key required
sailing_forecast_openmeteo	Open-Meteo — ECMWF, GFS, ICON, UKMO, Météo-France, JMA + Marine waves + optional SST	–
wind_consensus	Open-Meteo — many models side-by-side with min/max/spread	–
metar_taf	aviationweather.gov — real airport observations & terminal forecasts	–
sun_moon	Local calculation (SunCalc) — sunrise/sunset, twilights, moon phase	–
tides_nl	RWS Matroos — HW/LW, astronomical, observed, forecast + surge, water temp (preferred for NL)	–
tides_rws	RWS Waterinfo — observed water level (fallback)	–
marinas_osm	OpenStreetMap / Overpass — marinas, harbours, yacht clubs, anchorages, fuel	–
bridges_nl	NDW DATEX II — scheduled bridge openings (names via OSM)	–
notices_nl	RWS / EU NtS — official Notices to Skippers, geo-filtered	–
fairway_nl	RWS FIS WFS — fairway depths, bridge clearance (air draft), locks	–
checklists	Built-in — charter check-in, crew safety briefing, pre-departure, heavy weather, charter check-out. Rendered as an interactive checklist (MCP Apps) in Claude and ChatGPT	–
list_models	Built-in reference card (models, parameters, station codes)	–
sailing_forecast / point_forecast	Windy Point Forecast	Windy
tides_worldtides	WorldTides — global tide predictions	WorldTides
currents_stormglass	Stormglass — multi-source tidal/ocean currents	Stormglass
ais_traffic	AISStream — live vessel snapshot	AISStream

URL format

The server speaks Streamable HTTP on /mcp. Pass each provider's key as a query parameter (all optional):

https://your-host/mcp?key=WINDY&worldtidesKey=WT&stormglassKey=SG&aisstreamKey=AIS

Accepted aliases:

Provider	Query params	Headers
Windy	key, windyKey, apiKey	Authorization: Bearer …, X-Windy-Key, X-API-Key
WorldTides	worldtidesKey, wtKey	X-WorldTides-Key
Stormglass	stormglassKey, sgKey	X-Stormglass-Key
AISStream	aisstreamKey, aisKey	X-AISStream-Key

Where to get keys: Windy · WorldTides · Stormglass · AISStream. All except Windy have a usable free tier; everything else works with no key at all.

Local run

npm install
npm run dev          # tsx watch
# or
npm run build && npm start

Quick test:

curl -sS -X POST 'http://localhost:8787/mcp' \
  -H 'content-type: application/json' \
  -H 'accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

Deploy on a VPS

The included Dockerfile builds a small Node 22 image listening on :8787. Two ways to front it with TLS:

Option A — Docker Compose + Caddy (self-contained)

cp .env.example .env
$EDITOR .env          # set DOMAIN and ACME_EMAIL
docker compose up -d --build

Caddy obtains a Let's Encrypt certificate automatically and reverse-proxies to the container.

Option B — existing nginx

Run the container bound to localhost:

docker compose -f docker-compose.prod.yml up -d --build   # binds 127.0.0.1:8787

then add an nginx server block that proxies https://your-host → http://127.0.0.1:8787, with proxy_buffering off; on /mcp (the MCP Streamable HTTP transport needs unbuffered responses), and obtain a cert with certbot --nginx -d your-host.

Health check: GET /healthz → {"ok":true}. Landing page with a key-URL builder: GET /.

Connect from Claude

Claude Code

claude mcp add --transport http sailing "https://your-host/mcp?worldtidesKey=…&stormglassKey=…&aisstreamKey=…"

Claude.ai (Pro / Max / Team / Enterprise)

Settings → Connectors → Add custom connector → paste the URL. No OAuth required.

Claude Desktop (any plan, via mcp-remote)

{
  "mcpServers": {
    "sailing": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://your-host/mcp?...", "--transport", "http-only"]
    }
  }
}

Example prompts

"Tomorrow morning Den Helder → Texel: full passage plan — wind, gusts, waves, HW/LW at Marsdiep, when to leave and why."

"Wind consensus across ECMWF / GFS / ICON-EU / UKMO for Saturday at Marsdiep — where do the models disagree?"

"What ships are within 5 km of Marsdiep right now? Any TESO ferry inbound?"

"Find marinas with fuel within 20 km of IJmuiden, and the next bridge openings on the way."

Notes

• All provider keys are read per-request from the URL/headers and are never logged or persisted.
• All times returned by tools are UTC.
• tides_nl (Matroos) is more accurate than tides_worldtides in Dutch waters; prefer it there.
• NDW bridge data carries only RIS-index codes + coordinates; bridges_nl enriches them with bridge names from OpenStreetMap (nearest movable bridge within 80 m). A few may still show "(name unknown)" if OSM has no nearby named bridge.
• AISStream is community-fed; coverage is excellent in coastal Europe/Americas, sparse mid-ocean.
• This is provided as-is for sailing use. Always verify against official charts, almanacs and notices before relying on it for navigation safety.

Project layout

src/
  index.ts          # Express + Streamable HTTP transport, per-request key extraction
  server.ts         # MCP server, conditional tool registration
  keys.ts           # RequestKeys type
  landing.ts        # HTML landing page (GET /)
  openmeteo.ts      # Open-Meteo forecast + wind consensus
  windy.ts          # Windy Point Forecast client
  aviationweather.ts# METAR / TAF
  sunmoon.ts        # sun & moon (SunCalc)
  matroos.ts        # RWS Matroos tides (NL)
  rws.ts            # RWS Waterinfo (NL, fallback)
  worldtides.ts     # WorldTides global tides
  stormglass.ts     # Stormglass currents
  osm.ts            # OpenStreetMap / Overpass POIs
  ndw.ts            # NDW bridge schedule (DATEX II)
  nts.ts            # Notices to Skippers (RWS / EU NtS SOAP)
  fairway.ts        # Fairway depths / bridge clearance / locks (RWS FIS WFS)
  aisstream.ts      # AISStream live AIS snapshot
Dockerfile
docker-compose.yml        # + Caddy
docker-compose.prod.yml   # localhost-only, for existing nginx
Caddyfile

Built by @ai_kulikov.