medical.npi

Look up US healthcare providers in the CMS NPPES registry — the authoritative directory of National Provider Identifiers (NPIs). Give an exact 10-digit NPI, or search by provider last name (+ optional first name), or organization name, optionally narrowed by state and taxonomy/specialty. Returns each provider with NPI, entity type (individual vs organization), status, name/credential/gender or organization name, sole-proprietor flag, enumeration + last-updated dates, primary taxonomy, the full taxonomy list (code, description, primary flag, state license), and practice/mailing addresses with phone. Free, public-domain (CMS). The canonical "who is this NPI / find this provider" lookup for healthcare, claims, and credentialing agents.

price

$0.0011 USDC per call

method

GET/api/medical/npi

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
`npi`	string	match ^\d{10}$
`firstName`	string	min 1 chars · max 60 chars
`lastName`	string	min 1 chars · max 60 chars
`organization`	string	min 2 chars · max 120 chars
`state`	string	min 2 chars · max 2 chars
`taxonomy`	string	min 2 chars · max 80 chars
`limit`	integer	min 1 · max 50

Code samples

cURLbash

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/medical/npi?npi=12345&firstName=example&lastName=example&organization=xx&state=xx&taxonomy=xx&limit=1'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/medical/npi?npi=12345&firstName=example&lastName=example&organization=xx&state=xx&taxonomy=xx&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/medical/npi?npi=12345&firstName=example&lastName=example&organization=xx&state=xx&taxonomy=xx&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.medical.npi({
  "npi": "12345",
  "firstName": "example",
  "lastName": "example",
  "organization": "xx",
  "state": "xx",
  "taxonomy": "xx",
  "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.medical.npi(npi="12345", firstName="example", lastName="example", organization="xx", state="xx", taxonomy="xx", 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": "medical.npi",
    "arguments": {
      "npi": "12345",
      "firstName": "example",
      "lastName": "example",
      "organization": "xx",
      "state": "xx",
      "taxonomy": "xx",
      "limit": 1
    }
  }
}

Response

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

Example response datajson

{
  "ok": true,
  "items": [
    {
      "npi": "example",
      "enumerationType": "example",
      "entityType": "Individual",
      "status": "example",
      "firstName": "example",
      "lastName": "example",
      "credential": "example",
      "gender": "example",
      "organizationName": "example",
      "soleProprietor": "example",
      "enumerationDate": "example",
      "lastUpdated": "example",
      "primaryTaxonomy": "example",
      "taxonomies": [
        {
          "code": "example",
          "description": "example",
          "primary": false,
          "state": "example",
          "license": "example"
        }
      ],
      "addresses": [
        {
          "purpose": "example",
          "address1": "example",
          "address2": "example",
          "city": "example",
          "state": "example",
          "postalCode": "example",
          "countryCode": "example",
          "telephone": "example",
          "fax": "example"
        }
      ]
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

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.