Maritime Navigation API

Everything to connect is in one public repository: the OpenAPI specification, the data models, Python and JavaScript clients, an MCP server for Claude, Cursor, VS Code, Windsurf and Zed, and a GitHub Action that checks a route against the warnings in force. The endpoints stay the ones below; the kit is the way in.

• Editors and agents: add the MCP server and ask in plain words; the tools are search_warnings, warnings_near, route_check, navareas and feeds.
• Code: python/sealagom.py and js/sealagom.mjs, no dependencies beyond requests or fetch; generate any other language from openapi.yaml.
• No-code and agents: import sealagom.com/openapi.json into n8n, Make, Zapier, Pipedream, Postman, ChatGPT actions or LangChain. Send the key as X-API-Token or Authorization: Bearer.
• Routes: POST /api/v2/route/ with a route file or waypoints, or the drop link /api/v2/drop/<key>/route/ for tools that can only POST a file.
• Sky view: GET /api/v2/sky/link/?vessel= (or mmsi, warning and region, port, locode, lat and lon) gives a ready link that stands there in the sky view; POST /api/v2/sky/route/ takes a route and gives its sky link, drawn on the sea, with the RTZ and GPX. Section 20 of the README has the calls. Not for navigation.
• CI: the Action fails a build when a critical warning lies on a route kept in the repository.
• Scripts and agents paying for themselves: POST /api/agent/checkout/, crypto, the key once paid (in the profile when the e-mail already has an account).

API v2 uses the same token, plans and request accounting as v1. Everything under /api/v1/ keeps working exactly as before, so existing integrations need no change. v2 adds:

• One list of every warning: GET /api/v2/messages/, NAVAREA and coastal together, newest first, each message with its region, country and archive status.
• Message filters on the region endpoints: /api/v2/navarea/ and /api/v2/coastal/ answer like v1 and also apply date_from, date_to, keyword and has_coordinates to the messages they return.
• Settings saved on each token: pick a token on Profile > API > API v2 builder, build the response with menus and a live preview, and save. Every /api/v2/ call with that token returns that shape; /api/v1/ calls ignore saved settings and answer exactly as before.
• prompt filter (Full API):describe the warnings a token should return in your own words, for example "only space debris warnings around the USA".
• Integrate: the kit on GitHub (OpenAPI spec, clients, MCP server, Action) is the way in; a README.md per token, with its settings, plan and every parameter and field, is there for any program that wants one file.
• Settings file:instead of ticking options, ask LagoPal (with the README) for a settings file: a small JSON file with the token's endpoint, parameters and prompt. Load it on Profile > API (Load settings file); it fills the builder so you can check the live preview before saving. Download settings file gives the current settings in the same form. JSON Schema: /api/public/api-settings-schema/.

GET /api/v2/messages/

Fields or filters your plan does not include are left out and listed in meta.warnings, never an error.

content is the text as broadcast; content_en is the English text (the official English version or a machine translation) for sources that broadcast in another language, such as China or Turkey, and source_language names the original language.

The US Coast Guard Local Notices to Mariners (10 districts, updated weekly) are coastal regions titled US Coast Guard LNM, country US. They are not analysed, so their automatic fields are empty; each district also has one message, number LNMxx-DISCREPANCIES, listing its aids to navigation with a discrepancy.

curl "https://www.sealagom.com/api/v2/messages/?country=France&include_coordinates=true&include_ai_analysis=true" \
  -H "X-API-Token: YOUR_API_TOKEN"

{
  "count": 42,
  "page": 1,
  "page_size": 50,
  "next": null,
  "previous": null,
  "results": [
    {
      "scope": "coastal",
      "region_id": 57,
      "region_title": "FRANCE Atlantic",
      "country": "France",
      "is_archived": false,
      "archived_on": null,
      "id": 90211,
      "number": "AVURNAV 1234/26",
      "content": "BAY OF BISCAY. DRIFTING BUOY ...",
      "content_en": "BAY OF BISCAY. DRIFTING BUOY ...",
      "source_language": "en",
      "added_on": "2026-09-27T08:10:00Z",
      "coordinates": ["45-10.0N 002-05.0W"],
      "ai_analysis": { "headline": "...", "severity": "moderate", "valid_until": null }
    }
  ]
}

Settings saved on a token

• One token, one shape: each token keeps its own endpoint and parameters. Need a second shape (say France coastal with coordinates, and a worldwide feed)? Create a second token.
• Every option is shown, Full API ones included, with the plan each needs. Saving needs an active API plan.
• URL wins: any parameter you put in the URL replaces the saved value for that call; ?settings=off makes a plain call.
• Relative periods: "last 30 days" sends date_from as today minus 30 days on every call.
• Responses carry an X-API-Token-Settings header naming the token whose settings were applied.

Ice feed: GET /api/v2/ice/

• Every warning about ice at sea, from NAVAREA, coastal and NAVTEX sources: icebergs and iceberg limits, sea ice, ice edge, vessel icing and freezing spray, ice reports, icebreaker operations and ice navigation rules. An model reads each warning that mentions ice and keeps only those really about it, with its kind in ice.type.
• Positions, shapes (iceberg limit lines, ice areas) and the analysis are included by default. ?output=geojson returns a GeoJSON FeatureCollection, one feature per shape, ready for route checks and chart overlays.
• ice_type narrows it: iceberg, sea_ice, ice_edge, icing, ice_report, icebreaker, ice_navigation, other_ice (repeat or comma-separate). Every /api/v2/messages/ parameter also works, and /api/v2/messages/?topic=ice is the same feed.
• Full API plan, or an ice feed licence (annual, invoiced): contact us.

curl "https://www.sealagom.com/api/v2/ice/?output=geojson&ice_type=iceberg,ice_edge" -H "X-API-Token: YOUR_API_TOKEN"

Themed feeds: GET /api/v2/feeds/<feed>/

• Ready-made feeds built from the category the analysis gives every warning: military exercises and firing, rocket launches and space debris, cable and pipeline work, offshore works and rigs, surveys, wrecks and drifting hazards, aids to navigation, search and rescue, security and restricted areas.
• Same output as the ice feed: positions, shapes and the analysis by default, the category in feed.category, ?output=geojson for a FeatureCollection and ?category=to keep only some of a feed's categories. Every /api/v2/messages/ parameter also works, and /api/v2/messages/?topic=military is the same feed.
• Only warnings with an analysis are included. GET /api/v2/feeds/ (no token needed) lists every feed with how many of its warnings are in force.
• Full API plan, or a feed licence for a single feed (annual, invoiced): contact us.
• Free and without a token, for feed readers and scripts: RSS at /feeds/warnings.xml, /feeds/navarea/<id>.xml and /feeds/coastal/<id>.xml; the same three as Atom (.atom) and JSON Feed 1.1 (.json); plain text at /feeds/warnings.txt. The newest 100 warnings, text only, a warning keeps its id when it is updated. Region pages carry the feed links in their head, so a reader finds the feed from the page address.

Loading feeds…

curl "https://www.sealagom.com/api/v2/feeds/military/?output=geojson&navarea_id=3" -H "X-API-Token: YOUR_API_TOKEN"

prompt filter

• Write what you want in plain words on the token (Full API plan). When you save, a model checks every warning in force against it; each new warning is checked within about 10 minutes of arriving.
• /api/v2/messages/ calls with that token then return only the matching warnings. A warning that matched while in force stays matched after it is archived.
• The response adds meta.prompt_filter with the prompt, its status (matching right after saving, ready afterwards) and how many warnings matched. ?prompt_filter=off skips it for one call.
• The filter can miss or over-include a warning. Use it to narrow a feed, not as the only safety check; the official broadcast stays the authority.

# Token with saved settings: nothing else needed
curl "https://www.sealagom.com/api/v2/messages/" -H "X-API-Token: YOUR_API_TOKEN"

# Same token, override the period for one call
curl "https://www.sealagom.com/api/v2/messages/?date_from=2026-09-01" -H "X-API-Token: YOUR_API_TOKEN"

# Token with the prompt "only space debris warnings around the USA"
{
  "count": 3,
  "results": [ ... ],
  "meta": {
    "prompt_filter": {
      "prompt": "only space debris warnings around the USA",
      "status": "ready",
      "matched": 3
    }
  }
}