# Friday Seller Tools – Competitor Change Monitor Spec

> Friday Seller Tools – Competitor Change Monitor Spec is a paid API for AI agents from friday-seller-tools-production.up.railway.app, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-15).

Generates a specification/job for monitoring competitor product listing changes on e-commerce marketplaces like Amazon, Walmart, Shopify, and eBay.

## Facts

- Endpoint: POST https://friday-seller-tools-production.up.railway.app/v1/competitors/change-monitor-spec
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/friday-seller-tools-competitor-change-monitor-spec-5c3219fb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Jq_adDwdIc7t7AtzcWKSK

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 friday-seller-tools-competitor-change-monitor-spec-5c3219fb -d '<json body>'
```

Example prompt: Set up a competitor change monitor spec for my rival's Amazon ASIN B08XYZ1234 so I get alerted whenever they update their title, bullet points, price, or images.

## When to prefer this

Choose this endpoint when you need to programmatically set up automated competitor listing surveillance on major marketplaces (Amazon, Walmart, Shopify, eBay) without manual monitoring. Prefer this over generic web-scraping solutions when you need marketplace-aware change detection tuned to listing fields like price, title, bullets, and images, and when you want a low-cost ($0.25/call) queued job approach rather than a synchronous scrape.

## Known failure modes

- Missing required competitor product identifier returns 400 validation error
- Invalid marketplace identifier causes rejection
- Payment failure (insufficient USDC) returns 402 Payment Required
- Malformed URL or ASIN format returns validation error
- Server overload may return 503 with retry guidance
- Unsupported marketplace type may return 422 Unprocessable Entity

## How this service works

Instant, low-cost Amazon, Walmart, Shopify, and eBay listing, upload-preparation, advertising, and image-brief deliverables.

## Output

Returns a JSON object containing a job_id and a status field (e.g. 'queued'), confirming the change-monitor specification job has been accepted and queued for processing. The agent can use the job_id to poll for results or receive a completed monitoring spec.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "after": {
   "type": "object",
   "title": "CompetitorListingSnapshot",
   "required": [
    "captured_at"
   ],
   "properties": {
    "title": {
     "anyOf": [
      {
       "type": "string",
       "maxLength": 500,
       "minLength": 5
      },
      {
       "type": "null"
      }
     ],
     "title": "Title",
     "default": null
    },
    "rating": {
     "anyOf": [
      {
       "type": "number",
       "maximum": 5,
       "minimum": 0
      },
      {
       "type": "null"
      }
     ],
     "title": "Rating",
     "default": null
    },
    "bullets": {
     "type": "array",
     "items": {
      "type": "string",
      "maxLength": 1000,
      "minLength": 2
     },
     "title": "Bullets",
     "maxItems": 10
    },
    "price_usd": {
     "anyOf": [
      {
       "type": "number",
       "maximum": 1000000,
       "exclusiveMinimum": 0
      },
      {
       "type": "null"
      }
     ],
     "title": "Price Usd",
     "default": null
    },
    "captured_at": {
     "type": "string",
     "title": "Captured At",
     "format": "date"
    },
    "description": {
     "anyOf": [
      {
       "type": "string",
       "maxLength": 5000,
       "minLength": 10
      },
      {
       "type": "null"
      }
     ],
     "title": "Description",
     "default": null
    },
    "availability": {
     "anyOf": [
      {
       "enum": [
        "in_stock",
        "out_of_stock",
        "limited",
        "unknown"
       ],
       "type": "string"
      },
      {
       "type": "null"
      }
     ],
     "title": "Availability",
     "default": null
    },
    "review_count": {
     "anyOf": [
      {
       "type": "integer",
       "maximum": 1000000000,
       "minimum": 0
      },
      {
       "type": "null"
      }
     ],
     "title": "Review Count",
     "default": null
    }
   },
   "additionalProperties": false
  },
  "before": {
   "type": "object",
   "title": "CompetitorListingSnapshot",
   "required": [
    "captured_at"
   ],
   "properties": {
    "title": {
     "anyOf": [
      {
       "type": "string",
       "maxLength": 500,
       "minLength": 5
      },
      {
       "type": "null"
      }
     ],
     "title": "Title",
     "default": null
    },
    "rating": {
     "anyOf": [
      {
       "type": "number",
       "maximum": 5,
       "minimum": 0
      },
      {
       "type": "null"
      }
     ],
     "title": "Rating",
     "default": null
    },
    "bulle
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "job_id": "example",
  "status": "queued"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/friday-seller-tools-competitor-change-monitor-spec-5c3219fb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from friday-seller-tools-production.up.railway.app](https://www.zero.xyz/host/friday-seller-tools-production.up.railway.app/llms.txt)