# Check a product page (`mttr_product_check`)

Updated October 24, 2026.

## What does mttr_product_check do?

Checks one live product page’s structured data field by field against the fields search engines list for merchant listings, and guesses whether a shopper can buy on the page. Any key may make this call, on any public site.

Who may call it: Any key.

## When to use it

- Before and after a fix to a product template.
- When products do not show as listings and you want to know why.

## What you ask

You might say: “Check the product data on https://example.com/products/linen-shirt.”

```
mttr_product_check({ url: "https://example.com/products/linen-shirt" })
```

| Argument | Type | Needed | What it is |
| --- | --- | --- | --- |
| `url` | Text | Yes | The product page, as a full public address such as https://example.com/products/linen-shirt. |

## What comes back

- Each field present, missing or invalid, with what to do.
- A guess at whether a shopper can buy on the page.
- It reads only what the page publishes; listing eligibility is decided elsewhere.

A sample, with made-up sites and figures:

| Field | Found | What to do |
| --- | --- | --- |
| name | Present | Nothing |
| price | Present | Nothing |
| availability | Missing | Add it to each offer |
| gtin | Missing | Add it where the product has one |

## Over HTTP

```
curl "https://mttr.si/api/v1/check/product?url=https%3A%2F%2Fexample.com%2Fproducts%2Flinen-shirt" \
  -H "Authorization: Bearer $MTTR_KEY"
```

## When it fails

| When | Status | What to do |
| --- | --- | --- |
| Your assistant has no key yet | 401 over MCP | Sign up with `mttr_signup`, then connect again with the key it gives. |
| The key has used this hour’s free checks | 429 | The answer says product checks are limited to an hourly allowance. Try again within the hour. |

## Sources

- [Model Context Protocol: tools](https://modelcontextprotocol.io/specification/2025-06-18/server/tools), Model Context Protocol: How an assistant calls a tool.
- [Product structured data](https://developers.google.com/search/docs/appearance/structured-data/product), Google Search Central: The product fields a search engine reads, and which it needs.

The call in full: [mttr_product_check in the API reference](https://mttr.si/docs/reference#mttr_product_check).

## Goes with

- [One page](https://mttr.si/docs/tools/page.md)
- [Pages](https://mttr.si/docs/tools/pages.md)