Solutions · Port Calls API

Arrivals, departures and time in port

Every stop a vessel makes in a port, derived from its AIS positions: when it arrived, when it left and how long it stayed. Filter by port or vessel, and get a webhook for each arrival and departure.

Proof of delivery and ETA updates for shippers
Port-call history for chartering
Demurrage and laytime tracking

Get a free API key See the webhooks

Request

# Calls by port, mmsi, status (in_port or departed) and since
curl "https://seasignals.com/v1/port-calls?port=NLRTM&status=in_port" \
  -H "Authorization: Bearer $SS_KEY"

Endpoints

Query it whenever you need it

GeoJSON responses with typed IDs, ISO 8601 times and units in every field name. Errors come back as {"error": {"code", "message"}}.

GET/v1/port-callsCalls by port, mmsi, status (in_port or departed) and since

GET/v1/portsPorts with UN/LOCODE ids and whether they're in live coverage

Webhooks

Or let the events come to you

Subscribe a URL once and SeaSignals POSTs a signed JSON event whenever something changes. Sent within about 10 minutes of the vessel stopping or leaving.

EVENTport_call.arrivedA vessel stopped inside a watched port

EVENTport_call.departedIt left the port, with its total stay

Filters

`ports`	UN/LOCODEs, e.g. ["NLRTM", "BEANR"]; all ports when left out
`mmsi`	Only these vessels

Create a webhook

curl -X POST https://seasignals.com/v1/webhooks \
  -H "Authorization: Bearer $SS_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "url": "https://example.com/hooks/seasignals",
  "product": "port_calls",
  "events": [
    "port_call.arrived",
    "port_call.departed"
  ],
  "filters": {
    "ports": [
      "NLRTM",
      "BEANR"
    ]
  }
}'

POST to your URL

{
  "id": "evt_3kV9q2mXw8rT1yLp0aZc4nB7",
  "type": "port_call.departed",
  "created_at": "2026-10-29T09:00:12Z",
  "webhook": "webhook:42",
  "data": {
    "id": "port_call:8812",
    "status": "departed",
    "port": {
      "id": "port:NLRTM",
      "name": "Rotterdam",
      "country": "NL"
    },
    "vessel": {
      "id": "vessel:mmsi:244123456",
      "mmsi": 244123456,
      "name": "NORDIC STAR",
      "type": "cargo"
    },
    "arrived_at": "2026-10-27T22:10:00Z",
    "departed_at": "2026-10-29T06:40:00Z",
    "stay_hours": 32.5
  }
}

Delivery

Signed, retried, logged

Signed: every request carries SeaSignals-Signature, an HMAC-SHA256 of the timestamp and body with your webhook secret.
Retried: anything but a 2xx within 10 seconds is retried after 1 min, 5 min, 30 min, 2 h and 6 h.
Logged: GET /v1/webhooks/{id} shows recent deliveries, and POST /v1/webhooks/{id}/test sends a test event.
Safe to retry: use the event id to ignore a delivery you've already handled.

// header: SeaSignals-Signature: t=1761729600,v1=5f2b…
const [t, v1] = header.split(",").map((p) => p.split("=")[1]);
const expected = crypto.createHmac("sha256", process.env.SS_WEBHOOK_SECRET)
  .update(`${t}.${rawBody}`).digest("hex");
const ok = crypto.timingSafeEqual(Buffer.from(v1), Buffer.from(expected))
  && Date.now() / 1000 - Number(t) < 300;

import hashlib, hmac, os, time

t, v1 = (part.split("=")[1] for part in header.split(","))
expected = hmac.new(os.environ["SS_WEBHOOK_SECRET"].encode(),
                    f"{t}.{raw_body}".encode(), hashlib.sha256).hexdigest()
ok = hmac.compare_digest(v1, expected) and time.time() - int(t) < 300

t, v1 = header.split(",").map { _1.split("=").last }
expected = OpenSSL::HMAC.hexdigest("SHA256", ENV["SS_WEBHOOK_SECRET"], "#{t}.#{raw_body}")
ok = ActiveSupport::SecurityUtils.secure_compare(v1, expected) && Time.now.to_i - t.to_i < 300

One key for every API

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Marine Life API

Whale, dolphin, shark and turtle sightings

Try the Port Calls API free

The free trial includes every API and up to 5 webhooks, 1,000 requests a day and 14 days of history.

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