An AIS green CII API returns estimated CO₂ and an IMO Carbon Intensity Indicator rating for one ship. On Vessels API that is GET https://vessels-api.com/api/V1/vessels/green with header X-API-Key. Official docs sample: MMSI 258785000, IMO 9702510, name ZJ ATLANTIC, period 30d, rating C, co2_tons 1850.3. Coverage window in that fixture: 2026-01-10 … 2026-02-09.
Starter is $19.99/mo (2,500 calls) with a 7-day trial. CII scale in docs: A (best) → E. Method: internal_model_v1 (IMO MEPC.339(76) using type, distance, estimated fuel). MCP: mcp.vessels-api.com (tool green). Docs: #ep-green.
Request: official MMSI, 30 days
curl -H "X-API-Key: YOUR_API_KEY" \
"https://vessels-api.com/api/V1/vessels/green?mmsi=258785000&period=30d"
Response: official green sample
{
"status": 200,
"success": true,
"message": "OK",
"data": {
"imo": "9702510",
"mmsi": "258785000",
"name": "ZJ ATLANTIC",
"period": "30d",
"data_coverage": {
"positions": 412,
"first_position_utc": "2026-01-10T08:00:00Z",
"last_position_utc": "2026-02-09T10:30:00Z",
"last_position_age_minutes": 12
},
"distance_nm": 4200,
"estimated_emissions": {
"co2_tons": 1850.3,
"co2_per_nm": 0.44,
"method": "internal_model_v1"
},
"cii": {
"score": 13.2,
"rating": "C",
"year": 2026,
"regulation_reference": "IMO CII"
}
}
}
This is not live position (Professional+ quota) and not a chokepoint count.
Go live
1. Register — 7-day trial.
2. Copy X-API-Key.
3. GET /api/V1/vessels/green.
4. Persist cii.rating and estimated_emissions.co2_tons.
