class.industry-resolve

Cross-walk an industry classification code across the four major systems: NAICS <-> SIC <-> ISIC Rev.4 <-> NACE Rev.2. Pass the system + code and get the equivalent code(s) in every other system, with official titles where available, plus the vintage of each table used. The deterministic join that lets a KYC, procurement, ERP, or cross-border-reporting agent translate "what industry is this" between the US (NAICS/SIC), international (ISIC), and EU (NACE) standards. Backed by bundled public-domain Census concordances (NAICS<->SIC: 1997 NAICS <-> 1987 SIC; NAICS<->ISIC: 2012 NAICS <-> ISIC Rev.4) and the UNSD ISIC Rev.4 <-> NACE Rev.2 correspondence. Multi-hop links (e.g. SIC->NACE via NAICS->ISIC) are derived and explicitly flagged in notes. SIC is a retired US system; there is no newer NAICS<->SIC table.

Overview

The industry resolve API is a pay-per-call class endpoint built for AI agents and autonomous software. Cross-walk an industry classification code across the four major systems: NAICS <-> SIC <-> ISIC Rev.4 <-> NACE Rev.2.

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 industry resolve data source for an agent tool-use loop, an MCP host, or a backend that needs class data on demand without onboarding to yet another vendor portal.

Use cases

• Give an AI agent live industry resolve lookups as a tool, with no API key to provision or rotate — the agent pays per call from a wallet you fund.
• Enrich records in a data pipeline with class data, paying only for the calls you actually make instead of a monthly seat.
• Ground LLM answers in authoritative class data to cut hallucination, then optionally request a signed response for verifiability.
• Prototype against the live industry resolve API in minutes using the free trial call, then flip to per-call x402 payment for production with no code change.

Parameters

Code samples

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/class/industry-resolve?system=naics&code=example'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/class/industry-resolve?system=naics&code=example' \
  -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/class/industry-resolve?system=naics&code=example'

import { TwoS } from '@2sio/sdk'

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

const result = await client.class.industryResolve({
  "system": "naics",
  "code": "example"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)

import os
from twosio import TwoS

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

result = client.class.industry_resolve(system="naics", code="example")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)

// 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": "class.industry-resolve",
    "arguments": {
      "system": "naics",
      "code": "example"
    }
  }
}

Response

{
  "ok": true,
  "items": [
    {
      "resolvedFrom": "naics",
      "input": "example",
      "naics": [
        {
          "code": "example",
          "title": "example"
        }
      ],
      "sic": [
        {
          "code": "example",
          "title": "example"
        }
      ],
      "isic": [
        {
          "code": "example",
          "title": "example"
        }
      ],
      "nace": [
        {
          "code": "example"
        }
      ],
      "vintages": {
        "naics": "example",
        "sic": "example",
        "isic": "example",
        "nace": "example"
      },
      "notes": [
        "example"
      ]
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

FAQ

Do I need an API key to use the industry resolve API?

No. class.industry-resolve 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 industry resolve API cost?

$0.0036 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 industry resolve 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 class.industry-resolve 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

• /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