# Schema creator (`mttr_schema_create`)

Updated October 24, 2026.

## What does mttr_schema_create do?

Makes JSON-LD for one page from the values given, with the fields Google marks required or recommended for each type, and fetches nothing. Empty fields are left out, never made up. Any key may make this call, on any public site.

Who may call it: Any key.

## When to use it

- A page has no structured data and you know what it should say.
- You want markup that the schema markup checker will pass before you put it in a template.

## What you ask

You might say: “Make LocalBusiness JSON-LD for Acme Plumbing in Phoenix, phone +1-602-555-0142.”

```
mttr_schema_create({ type: "LocalBusiness" })
```

| Argument | Type | Needed | What it is |
| --- | --- | --- | --- |
| `type` | One of these: LocalBusiness, Organization, Product, Article, BreadcrumbList, Service, Event, WebSite | Yes | The schema type to make. |
| `as` | Text | No | A more exact type, for LocalBusiness (such as Plumber, RoofingContractor, Restaurant) or Article (BlogPosting, NewsArticle). |
| `fields` | Fields | No | The values, by field key, as text: such as { "name": "Acme Plumbing", "city": "Phoenix", "telephone": "+1-602-555-0142" }. Lists, such as images, are one value a line. |

## What comes back

- The JSON-LD as data, and inside its script tag ready to paste.
- The required fields left empty, and what is not right.
- The recommended fields left out.
- Every field the type takes, with its key.

A sample, with made-up sites and figures:

| Field | Need | Given |
| --- | --- | --- |
| name | Required | Acme Plumbing |
| address | Required | Phoenix |
| telephone | Recommended | +1-602-555-0142 |
| openingHoursSpecification | Recommended | Left out |

## Over HTTP

```
curl "https://mttr.si/api/v1/make/schema?type=LocalBusiness" \
  -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. |

## Sources

- [Model Context Protocol: tools](https://modelcontextprotocol.io/specification/2025-06-18/server/tools), Model Context Protocol: How an assistant calls a tool.
- [Schema.org](https://schema.org/), Schema.org: The types and properties the structured data is made of.
- [Introduction to structured data markup](https://developers.google.com/search/docs/appearance/structured-data/intro-structured-data), Google Search Central: How a search engine reads structured data, and what it asks of it.

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

## Goes with

- [Check a product page](https://mttr.si/docs/tools/product-check.md)
- [What an agent reads](https://mttr.si/docs/tools/agent-view.md)