# Livecheck Watcher Chain Top-Up

> Livecheck Watcher Chain Top-Up is a paid API for AI agents from livecheck.fly.dev, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-15).

Adds USDC credit to an existing Livecheck watcher's chain budget so it can continue running scheduled verification checks.

## Facts

- Endpoint: POST https://livecheck.fly.dev/v1/watch/%7Bid%7D/chain/topup
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/livecheck-watcher-chain-top-up-e0a5cf7c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JjfdSIzrUzLgJllNFRGdr

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 livecheck-watcher-chain-top-up-e0a5cf7c -d '<json body>'
```

Example prompt: Top up watcher wtc_01J8Z0K3N4P5Q6R7S8T9V0WWTC with another $0.50 so it keeps running its verification checks.

## When to prefer this

Use this endpoint when you already have an active Livecheck watcher (wtc_ ID) whose chain balance is low or exhausted and you want to refill its budget so scheduled verification runs continue uninterrupted. This is not for creating new watchers or performing one-shot checks — use the /v1/watch or /v1/check endpoints for those.

## Known failure modes

- Invalid or non-existent watcher ID returns an error
- Insufficient payment (below $0.50 per-call price) causes payment rejection
- Malformed watcher ID format (not wtc_ + ULID) returns validation error
- Watcher already expired or deleted may return not-found error
- Payment gateway failure or x402 protocol error prevents top-up

## How this service works

Before you scrape a job posting, Shopify or HTML product page, or eBay item, POST the specific URL you already have and Livecheck returns live, closed, or unknown plus title and signals (apply form, in-stock, sold-out, 404); not a search engine.

## Output

Returns the watcher ID, the amount added in USD, the updated chain balance in USD, the per-check price in USD, the total chain budget in USD, and the current run status (none or verify).

## 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": {
     "required": [],
     "properties": {}
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "id",
      "added_usd",
      "chain_balance_usd",
      "price_usd",
      "run"
     ],
     "properties": {
      "id": {
       "type": "string",
       "description": "Watcher id (wtc_ + ULID)."
      },
      "run": {
       "enum": [
        "none",
        "verify",
        "confirm"
       ],
       "type": "string"
      },
      "added_usd": {
       "type": "number"
      },
      "price_usd": {
       "type": "number"
      },
      "chain_budget_usd": {
       "type": [
        "number",
        "null"
       ]
      },
      "chain_balance_usd": {
       "type": "number"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": "wtc_01J8Z0K3N4P5Q6R7S8T9V0WWTC",
  "run": "verify",
  "added_usd": 0.5,
  "price_usd": 0.5,
  "chain_budget_usd": 5,
  "chain_balance_usd": 0.5
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/livecheck-watcher-chain-top-up-e0a5cf7c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from livecheck.fly.dev](https://www.zero.xyz/host/livecheck.fly.dev/llms.txt)