the402 endpoint detail

← All endpoints

port-scanner.underscoredone.com scan

https://port-scanner.underscoredone.com/scan

answers 402

Give this API a hostname or IP address and it will try connecting to each port in your requested range. For every port that answers, it tells you whether it is open or blocked, which service is likely running there (like a web server or SSH), and what software version was detected. This saves you from installing network tools, parsing messy command-line output, or writing socket loops yourself. On

We sent a real POST request to this endpoint and it answered 402 with payment requirements we could parse.
Price
$0.01
Network
base
Pay to
0xE9740820225B3918b4ddd1292C7cA4Ca0e2C2F08
Spec dialect
v2 (declares x402Version 2)
Transport
PAYMENT-REQUIRED header
HTTP method
POST
Response latency
113 ms
Payment options
2 usable of 2
Last checked
2026-08-15T14:22:01.627Z (13h ago)
Category
finance-crypto

Re-check it yourself:
curl "https://api.the402.dev/validate?url=https%3A%2F%2Fport-scanner.underscoredone.com%2Fscan"