check_password_prefix

Pack: hibp · Endpoint: https://gateway.pipeworx.io/hibp/mcp

Direct k-anonymity lookup: pass the first 5 hex chars of a SHA-1 password hash, get back all SHA-1 suffixes with their pwned counts. Use this if you’re hashing client-side and only want to send the prefix.

Parameters

Example call

Arguments

{
  "sha1_prefix": "21BD1"
}

curl

curl -X POST https://gateway.pipeworx.io/hibp/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"check_password_prefix","arguments":{"sha1_prefix":"21BD1"}}}'

TypeScript (@pipeworx/sdk)

import { Pipeworx } from '@pipeworx/sdk';
const pipeworx = new Pipeworx();

const result = await pipeworx.call('check_password_prefix', {
  "sha1_prefix": "21BD1"
});

More examples

{
  "sha1_prefix": "CBFDA"
}

Response shape

Always returns: sha1_prefix, suffix_count, suffixes

{
  "type": "object",
  "properties": {
    "sha1_prefix": {
      "type": "string",
      "description": "The 5-character SHA-1 prefix provided"
    },
    "suffix_count": {
      "type": "number",
      "description": "Number of matching SHA-1 suffixes found"
    },
    "suffixes": {
      "type": "array",
      "description": "Array of suffix/count pairs matching this prefix",
      "items": {
        "type": "object",
        "properties": {
          "suffix": {
            "type": "string",
            "description": "SHA-1 suffix (35 hex chars after prefix)"
          },
          "count": {
            "type": "number",
            "description": "Number of times this hash seen in breaches"
          }
        },
        "required": [
          "suffix",
          "count"
        ]
      }
    }
  },
  "required": [
    "sha1_prefix",
    "suffix_count",
    "suffixes"
  ]
}

Connect

Add this to your MCP client config, or use one-click install buttons:

{
  "mcpServers": {
    "hibp": {
      "url": "https://gateway.pipeworx.io/hibp/mcp"
    }
  }
}

See Getting Started for client-specific install steps.