# Bot Bazaar EIP-3009 Nonce Collision Check

> Bot Bazaar EIP-3009 Nonce Collision Check is a paid API for AI agents from bot-bazaar.fly.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30).

Validates a 32-byte hex EIP-3009 authorization nonce for bit entropy, sequential/zero-padding traps, and replay safety.

## Facts

- Endpoint: GET https://bot-bazaar.fly.dev/v1/x402/nonce-collision-check?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bot-bazaar-eip-3009-nonce-collision-check-b228def2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_EY7C8nical-30SXy6f-rg

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 bot-bazaar-eip-3009-nonce-collision-check-b228def2
```

Example prompt: Can you check whether this nonce is safe to use in an EIP-3009 authorization — I want to make sure it has strong entropy and won't trigger any sequential or zero-padding traps: 0x3a9f1c8e7b2d04f56a1e8c3d9b7042f1a6e3c8d27b4f9a1e5c3d8b7042f96a1?

## When to prefer this

Choose this endpoint when building EIP-3009 meta-transaction flows on Base or EVM chains and you need to programmatically verify that a generated nonce is cryptographically sound before signing. Particularly valuable for AI agent payment pipelines where nonces are generated automatically and must not be weak, sequential, or reused. Prefer this over ad-hoc entropy checks when you need structured replay-safety signals and zero-padding trap detection in a single call.

## Known failure modes

- Nonce not provided or malformed (missing 0x prefix, wrong length) — likely returns a validation error
- Nonce is all zeros or trivially sequential — flagged as unsafe but not an API error
- Service unavailable on fly.dev instance — network timeout or 5xx
- Non-hex characters in nonce string — input rejection error

## How this service works

Validate a 32-byte hex EIP-3009 authorization nonce for bit entropy, sequential/zero-padding traps, and replay safety.

## Output

Returns an assessment of the provided 32-byte hex nonce including: bit entropy score, detection of sequential or zero-padded patterns that indicate weak randomness, and replay safety classification — helping agents determine whether the nonce is safe to use in an EIP-3009 authorization flow.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "nonce": {
       "type": "string",
       "description": "32-byte hex nonce (0x + 64 hex)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bot-bazaar-eip-3009-nonce-collision-check-b228def2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bot-bazaar.fly.dev](https://www.zero.xyz/host/bot-bazaar.fly.dev/llms.txt)