security.password-exposure

Check whether a password has appeared in known data breaches, using Have I Been Pwned's Pwned Passwords k-anonymity model — only the first 5 characters of the password's SHA-1 hash are ever sent upstream, so the service never sees the password or the full hash. POST { password } (hashed server-side) OR { sha1 } (the 40-hex SHA-1, for true zero-knowledge — hash it client-side and send only that). Returns breached (boolean), count (how many times it appears in breach corpora), and the sha1Prefix used. Backed by a 900M+ breached-credential corpus an LLM cannot know. For signup/password-policy enforcement and credential-hygiene checks. Absence is not a guarantee of strength.

price
$0.0010 USDC per call
method
POST/api/security/password-exposure
payment
x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)
auth
None. Sign the payment, retry with PAYMENT-SIGNATURE.

Overview

The password exposure API is a pay-per-call security endpoint built for AI agents and autonomous software. Check whether a password has appeared in known data breaches, using Have I Been Pwned's Pwned Passwords k-anonymity model — only the first 5 characters of the password's SHA-1 hash are ever sent upstream, so the service never sees the password or the full hash.

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

Use cases

Parameters

NameTypeDescription
passwordstring
min 1 chars · max 512 chars
sha1string
min 40 chars · max 40 chars

Code samples

cURLbash
# 1. Probe the endpoint with no auth — receive 402 with PaymentRequirements
curl -sS -X POST 'https://2s.io/api/security/password-exposure' \
  -H 'Content-Type: application/json' \
  -d '{"password":"example","sha1":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"}'

# 2. Sign the EIP-3009 transferWithAuthorization for the advertised price +
#    payTo from the 402 envelope, then retry with PAYMENT-SIGNATURE:
curl -sS -X POST 'https://2s.io/api/security/password-exposure' \
  -H 'Content-Type: application/json' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>' \
  -d '{"password":"example","sha1":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"}'

# Or just use the canonical runner — it handles the whole loop:
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/security/password-exposure'
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.security.passwordExposure({
  "password": "example",
  "sha1": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
})

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.security.password_exposure(password="example", sha1="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")

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": "security.password-exposure",
    "arguments": {
      "password": "example",
      "sha1": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    }
  }
}

Response

FieldTypeDescription
okboolean
one of: true
itemsarray
totalintegerTotal matching rows upstream; null when unknown.
sourceobject
Example response datajson
{
  "ok": true,
  "items": [
    {
      "breached": false,
      "count": 1,
      "sha1Prefix": "example",
      "inputMode": "example",
      "note": "example"
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

FAQ

Do I need an API key to use the password exposure API?
No. security.password-exposure 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 password exposure API cost?
$0.0010 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 password exposure 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 security.password-exposure 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

Related: password exposure api · security password exposure api · password exposure api for ai agents · x402 security api · password exposure api no api key · pay per call password exposure api · security api