# Password Strength Estimator (zxcvbn-style)

> Password Strength Estimator (zxcvbn-style) is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.0022/call, status unknown (last checked 2026-09-14).

Estimates password strength using zxcvbn-style heuristics, returning a score 0-4, crack time estimate, and feedback for weak passwords.

## Facts

- Endpoint: GET https://api.x402node.dev/password/strength
- Price: $0.0022/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-x402node-dev-8dd50696
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7I5-zrG5tsqRQcfD0xWS3

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability api-x402node-dev-8dd50696
```

Example prompt: How strong is the password 'Tr0ub4dor&3' — give me its score out of 4, estimated crack time, and any feedback on how to improve it.

## When to prefer this

Use this endpoint when you need a programmatic, zxcvbn-style password strength score with crack time estimates and human-readable feedback — ideal for form validation flows, user onboarding security checks, or auditing stored passwords for weakness without rolling your own heuristics.

## Known failure modes

- Missing password field in request body returns 400 error
- Empty string password may return score of 0 with no crack time
- Very long passwords may have unexpected behavior
- Payment failure returns 402 if USDC not provided

## How this service works

Password strength estimator, score 0-4, zxcvbn-style heuristics, crack time, weak password detection. Returns score, feedback, estimated crack time. Accepts payment on Base or Solana — either network works.

## Output

Returns a numeric strength score (0-4, where 0 is very weak and 4 is very strong), an estimated time-to-crack string, and actionable feedback/suggestions for improving weak passwords.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "password": {
       "type": "string",
       "description": "Password (optional)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-x402node-dev-8dd50696/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402node.dev](https://www.zero.xyz/host/api.x402node.dev/llms.txt)