dns.lookup

Resolve a hostname over public DNS and return parsed records. Query: host (required FQDN), types (comma-separated: A,AAAA,MX,TXT,NS,CAA,SRV,CNAME,PTR,SOA — default A,AAAA,MX,TXT,NS), resolver (cloudflare|google|quad9|opendns, optional). Returns one normalized JSON shape per record type with per-type error pass-through. Reserved/local TLDs (.local, .internal, .invalid, .test, localhost) are rejected. 4s per-query timeout.

price

$0.0010 USDC per call

method

GET/api/dns/lookup

payment

x402 v2 · EIP-3009 transferWithAuthorization · USDC on Base mainnet

auth

None. Sign the payment, retry with PAYMENT-SIGNATURE.

tier

Tier 0 — no paid upstream

Parameters

Name	Type	Description
`host`required	string	min 1 chars · max 253 chars
`types`	string	match ^(A\|AAAA\|MX\|TXT\|NS\|CAA\|SRV\|CNAME\|PTR\|SOA)(,(A\|AAAA\|MX\|TXT\|NS\|CAA\|SRV\|CNAME\|PTR\|SOA)){0,9}$
`resolver`	string	one of: cloudflare \| google \| quad9 \| opendns

Code samples

cURLbash

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/dns/lookup?host=example&types=example&resolver=cloudflare'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/dns/lookup?host=example&types=example&resolver=cloudflare' \
  -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/dns/lookup?host=example&types=example&resolver=cloudflare'

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.dns.lookup({
  "host": "example",
  "types": "example",
  "resolver": "cloudflare"
})

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.dns.lookup(host="example", types="example", resolver="cloudflare")

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": "dns.lookup",
    "arguments": {
      "host": "example",
      "types": "example",
      "resolver": "cloudflare"
    }
  }
}

Discovery

/api/directory — full catalog of every endpoint
/openapi.json — OpenAPI 3.1 spec (per-op x-payment-info, x402Payment security)
/.well-known/x402 — machine-readable service descriptor for x402-aware crawlers
/.well-known/mcp/server-card.json — MCP SEP-1649 server card
/llms.txt — plain-text manifest for LLM ingestion

2s.io is x402-native. Every call is paid per-request from a USDC-funded EVM wallet on Base — no signup, no API keys, no monthly fees. Source code: github.com/2s-io/sdk.