business.naics

Look up or search NAICS 2022 industry classification codes (US Census Bureau, public domain). Pass `code` for an exact NAICS code — 2–6 digits or a combined sector like 31-33 — and get its official title, hierarchy path, full official description, activity index terms, and direct child codes. Or pass `query` for free-text search (e.g. 'software publishers', 'coffee shop') over titles plus the official ~20k-entry activity index → ranked candidate codes, optionally filtered by `level` (2=sector … 6=national industry). Ground truth for industry coding in KYC, business registration, government filings, and ERP vendor/customer setup.

price

$0.0010 USDC per call

method

GET/api/business/naics

payment

x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)

auth

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

tier

Tier 0 — no paid upstream

Parameters

Name	Type	Description
`code`	string	Exact NAICS code (2–6 digits, or a combined sector range like 31-33). XOR with query. match ^(\d{2}-\d{2}\|\d{2,6})$
`query`	string	Free-text industry or activity description to search. XOR with code. min 2 chars · max 120 chars
`level`	integer	Search mode only: restrict results to one hierarchy level (2=sector … 6=national industry). min 2 · max 6
`limit`	integer	Search mode only: max results, 1–50, default 20. min 1 · max 50

Code samples

cURLbash

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/business/naics?code=example&query=xx&level=2&limit=1'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/business/naics?code=example&query=xx&level=2&limit=1' \
  -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/business/naics?code=example&query=xx&level=2&limit=1'

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.business.naics({
  "code": "example",
  "query": "xx",
  "level": 2,
  "limit": 1
})

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.business.naics(code="example", query="xx", level=2, limit=1)

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": "business.naics",
    "arguments": {
      "code": "example",
      "query": "xx",
      "level": 2,
      "limit": 1
    }
  }
}

Response

Field	Type	Description
`ok`	boolean	one of: true
`items`	array
`total`	integer	Total matching rows upstream; null when unknown.
`source`	object
`page`	object

Example response datajson

{
  "ok": true,
  "items": [
    {
      "code": "example",
      "level": 1,
      "title": "example",
      "heading": "example",
      "description": "example",
      "indexTerms": [
        "example"
      ]
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  },
  "page": {
    "number": 1,
    "size": 1,
    "pages": 1
  }
}

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.