# x402 Gateway Wallet Monitor

> x402 Gateway Wallet Monitor is a paid API for AI agents from x402-gateway-production-1f21.up.railway.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-10).

Monitors an Ethereum/Base wallet address for token transfer activity and detects state changes relative to a previous snapshot using deterministic hashing.

## Facts

- Endpoint: POST https://x402-gateway-production-1f21.up.railway.app/agent/wallet-monitor?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-gateway-wallet-monitor-f5740d96
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_41E84NeD5xf7SYq846cxO

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 x402-gateway-wallet-monitor-f5740d96 -d '<json body>'
```

Example prompt: Check if the wallet 0xAbC...123 has had any token transfer activity on Base in the last 2000 blocks, and compare it against my previous state hash 0xdeadbeef...1234 so I know if anything changed.

## When to prefer this

Choose this endpoint when you need deterministic, hash-based change detection for a specific wallet address on Base or Ethereum — particularly useful for polling loops where you want to detect any state change without downloading full event logs. Prefer this over generic block explorers when you need a lightweight, machine-payable per-call monitoring primitive that returns a comparable state hash.

## Known failure modes

- Invalid Ethereum address format (must match ^0x[a-fA-F0-9]{40}$) returns validation error
- lookback_blocks exceeds maximum of 5000 returns schema validation error
- Invalid previous_state_hash format (must be 64 hex chars) returns error
- Network not in enum ['base','ethereum'] returns error
- Token list exceeds 20 items returns error
- RPC node timeouts or blockchain data unavailability may cause failures
- Payment of 0.005 USDC not received causes x402 payment-required rejection

## How this service works

Recurring wallet monitor for crypto agents. Check native ETH plus selected ERC-20 balances and new USDC/ERC-20 transfers since the prior cursor, then return current_state_hash and next_cursor for the next scheduled check. Use for deposit detection, payment monitoring, treasury alerts and autonomous stablecoin workflows.

## Output

Returns a JSON object with a status field ('ready' or similar) indicating whether wallet activity was detected, along with a deterministic state hash representing current wallet state that can be compared to a previous hash to identify changes, plus any relevant transfer events found within the lookback window.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "cursor": {
       "type": "integer",
       "minimum": 0
      },
      "tokens": {
       "type": "array",
       "items": {
        "type": "string",
        "pattern": "^0x[a-fA-F0-9]{40}$"
       },
       "maxItems": 20
      },
      "address": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$"
      },
      "network": {
       "enum": [
        "base",
        "ethereum"
       ],
       "type": "string",
       "default": "base"
      },
      "lookback_blocks": {
       "type": "integer",
       "default": 1000,
       "maximum": 5000,
       "minimum": 1
      },
      "activity_contract": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$"
      },
      "previous_state_hash": {
       "type": "string",
       "pattern": "^[a-fA-F0-9]{64}$"
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "status": "ready"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-gateway-wallet-monitor-f5740d96/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-gateway-production-1f21.up.railway.app](https://www.zero.xyz/host/x402-gateway-production-1f21.up.railway.app/llms.txt)