maritime.vessel

Look up vessels in the US Coast Guard PSIX registry by name (partial match), call sign, official number, hull number (HIN), flag country, service type, or build year. Returns matching vessels with the USCG vessel id, name, call sign, service type, build year, status, official number, HIN, and flag. Keyless, public-domain. Covers US-flagged vessels (and foreign vessels with US port-state-control activity). Pair the returned vesselId with maritime.cases for the inspection record. (Cross-references trade.locode for ports.)

price
$0.0010 USDC per call
method
GET/api/maritime/vessel
payment
x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)
auth
None. Sign the payment, retry with PAYMENT-SIGNATURE.

Overview

The vessel API is a pay-per-call maritime endpoint built for AI agents and autonomous software. Look up vessels in the US Coast Guard PSIX registry by name (partial match), call sign, official number, hull number (HIN), flag country, service type, or build year.

There is no signup and no API key. An agent (or any HTTP client) hits the endpoint, receives an x402 "402 Payment Required" challenge, signs a sub-cent USDC payment on Base or Solana, and retries — the data comes back on the paid request. That makes it a drop-in vessel data source for an agent tool-use loop, an MCP host, or a backend that needs maritime data on demand without onboarding to yet another vendor portal.

Use cases

Parameters

NameTypeDescription
namestring
max 100 chars
callSignstring
max 40 chars
officialNumberstring
max 40 chars
hullNumberstring
max 40 chars
flagstring
max 60 chars
servicestring
max 60 chars
buildYearstring
match ^\d{4}$
vesselIdstring
match ^\d+$

Code samples

cURLbash
# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/maritime/vessel?name=example&callSign=example&officialNumber=example&hullNumber=example&flag=example&service=example&buildYear=12345&vesselId=12345'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/maritime/vessel?name=example&callSign=example&officialNumber=example&hullNumber=example&flag=example&service=example&buildYear=12345&vesselId=12345' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>'

# Or use the canonical runner (handles probe → sign → retry):
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/maritime/vessel?name=example&callSign=example&officialNumber=example&hullNumber=example&flag=example&service=example&buildYear=12345&vesselId=12345'
TypeScript / Node — @2sio/sdktypescript
import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.maritime.vessel({
  "name": "example",
  "callSign": "example",
  "officialNumber": "example",
  "hullNumber": "example",
  "flag": "example",
  "service": "example",
  "buildYear": "12345",
  "vesselId": "12345"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)
Python — 2siopython
import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.maritime.vessel(name="example", callSign="example", officialNumber="example", hullNumber="example", flag="example", service="example", buildYear="12345", vesselId="12345")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)
MCP — Claude Desktop / AgentKit / any MCP hostjson
// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
//    EVM_PRIVATE_KEY funds x402 payments per call.

// claude_desktop_config.json
{
  "mcpServers": {
    "2sio": {
      "command": "npx",
      "args": ["-y", "@2sio/mcp"],
      "env": { "EVM_PRIVATE_KEY": "0x..." }
    }
  }
}

// 2. Once the server is running, agents call this tool via standard MCP:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "maritime.vessel",
    "arguments": {
      "name": "example",
      "callSign": "example",
      "officialNumber": "example",
      "hullNumber": "example",
      "flag": "example",
      "service": "example",
      "buildYear": "12345",
      "vesselId": "12345"
    }
  }
}

Response

FieldTypeDescription
okboolean
one of: true
itemsarray
totalintegerTotal matching rows upstream; null when unknown.
sourceobject
Example response datajson
{
  "ok": true,
  "items": [
    {
      "vesselId": 1,
      "name": "example",
      "callSign": "example",
      "serviceType": "example",
      "buildYear": 1,
      "status": "example",
      "officialNumber": "example",
      "hullNumber": "example",
      "flag": "example"
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

FAQ

Do I need an API key to use the vessel API?
No. maritime.vessel is x402-native — there is no signup and no API key. Your client makes the call, receives a 402 with payment requirements, signs a USDC payment, and retries. Funds come from a wallet you control.
How much does the vessel API cost?
$0.0010 USDC per call, charged per request. There are no monthly fees, seats, or minimums — you pay only for the calls you make.
Can I try the vessel API for free first?
Yes. Add ?trial=1 (or the header X-2s-Trial: 1) to get a free real call per endpoint per hour, so you can verify the response shape before wiring payment.
Which networks and tokens are supported?
USDC on Base (via EIP-3009 transferWithAuthorization) or Solana (SPL transfer), using the open x402 payment protocol.
How do I call maritime.vessel from an AI agent or MCP host?
Use @2sio/sdk (TypeScript), 2sio (Python), or the @2sio/mcp server for any MCP host — each handles the probe → sign → retry loop for you. See the code samples on this page.

Discovery

Related: vessel api · maritime vessel api · vessel api for ai agents · x402 maritime api · vessel api no api key · pay per call vessel api · maritime api