# Duplicate customiser font tier (`duplicate_customiser_font_tier`)

Copies one font tier of a simple_letter customiser, with every row and price, into a new font tier on the same customiser. The copy is named name, or "Copy of" and the source name when name is omitted. No font uses the copy until update_customiser_option points a font font_tier_id at it, so the copy changes no storefront price. A customiser on another pricing model is refused with pricing_model_mismatch. It requires the pricing:write scope and an idempotency_key, and supports dry_run.

- Source URL: https://www.signcustomiser.com/help/mcp/tools/duplicate_customiser_font_tier/
- Markdown URL: https://www.signcustomiser.com/help/mcp/tools/duplicate_customiser_font_tier.md
- MCP endpoint: https://mcp.signcustomiser.com
- Required scope: `pricing:write`
- Behaviour: write

## Purpose

Start a new font tier from the prices of an existing one, for example to set different prices for some fonts.

## Annotations

| Hint | Value |
| --- | --- |
| readOnlyHint | false |
| destructiveHint | false |
| idempotentHint | true |
| openWorldHint | false |

## Prerequisites

- A simple_letter customiser id from list_customisers and a font tier id from list_customiser_font_tiers.
- A merchant has connected this store and approved the pricing:write scope.

## Side effects

- Creates one font tier on one customiser, a copy of the source tier.
- Clears the customiser cached storefront configuration.
- Spends one unit of the store option-write budget.
- Claims the idempotency_key for at least 24 hours.

## Arguments

| Property | Type | Required | Description |
| --- | --- | --- | --- |
| `customiser_id` | integer | yes | The customiser id, from list_customisers. |
| `font_tier_id` | integer | yes | The id of the font tier to copy, from list_customiser_font_tiers. |
| `name` | string | no | The name of the copy. Omit it for "Copy of" and the source name. |
| `idempotency_key` | string | unless `dry_run` is true | A client-generated key unique to this logical write, such as a UUID. Required: repeating the call with the same key and the same arguments replays the original result instead of writing twice, and the same key with different arguments is an idempotency_key_conflict. |
| `dry_run` | boolean | no | When true, the source tier and the customiser pricing model are checked is checked and nothing is written: the result is the same verdict the apply would have reached, and a problem the apply would have raised comes back as the same tool error. Defaults to false. A dry run claims no key. |

## Result

The new font tier with every row, in the shape get_customiser_font_tier returns. A dry run returns the duplicate verdict instead and writes nothing.

| Property | Type | Required | Description |
| --- | --- | --- | --- |
| `request_id` | string | yes |  |
| `store` | object | yes |  |
| `store.id` | integer | yes |  |
| `store.name` | string | yes |  |
| `customiser_id` | integer | yes |  |
| `source_font_tier_id` | integer | yes |  |
| `font_tier` | object | no | The new font tier with every row. Absent on a dry run. |
| `font_tier.id` | integer | yes |  |
| `font_tier.customiser_id` | integer | yes |  |
| `font_tier.name` | string or null | no |  |
| `font_tier.letter_pricing_mode` | string or null | no | One of: `every_letter_cost`, `price_by_position`. |
| `font_tier.currency` | string or null | no | The ISO 4217 currency of every integer minor-unit amount on the record. |
| `font_tier.rows` | array of object | no |  |
| `font_tier.rows[].size_id` | integer or null | no |  |
| `font_tier.rows[].base_price` | object | no |  |
| `font_tier.rows[].letter_price` | object | no |  |
| `font_tier.rows[].letter_price_by_position` | object or null | no |  |
| `font_tier.created_at` | string or null | no |  |
| `font_tier.updated_at` | string or null | no |  |
| `idempotent_replay` | boolean | no | True when this call replayed a previously recorded response for the same idempotency_key instead of applying the write again. |
| `dry_run` | boolean | no | Present and true only when dry_run was requested. |
| `valid` | boolean | no | Present only on a dry run, and always true: a failing dry run returns a tool error instead. |
| `verdict` | object | no | Present only on a dry run: the duplicate verdict. |

## Error cases

| Code | Recovery |
| --- | --- |
| `idempotency_subject_changed` | The copy was later deleted. Issue a new key and re-check the resource before writing again. |
| `insufficient_scope` | The connection was approved without pricing:write. |
| `pricing_model_mismatch` | The customiser does not price by simple_letter, so a font tier would never be used. |
| `rate_limited` | The store option-write budget is spent. Wait retry_after seconds. |
| `resource_not_found` | No font tier with that id belongs to that customiser in this store. |
| `unknown_field` | Remove the field named by pointer; the duplicate takes only name. |
| `validation_failed` | The name is longer than 255 characters. The pointer names it. |

## Example: Copy a tier under a new name

Request:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "duplicate_customiser_font_tier",
    "arguments": {
      "customiser_id": 42,
      "font_tier_id": 7,
      "name": "Premium",
      "idempotency_key": "c4d5e6f7-a8b9-4c0d-9e1f-2a3b4c5d6e7f"
    }
  }
}
```

Response:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "structuredContent": {
      "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t",
      "store": {
        "id": 12,
        "name": "Demo Signs"
      },
      "customiser_id": 42,
      "source_font_tier_id": 7,
      "font_tier": {
        "id": 8,
        "customiser_id": 42,
        "name": "Premium",
        "letter_pricing_mode": "every_letter_cost",
        "currency": "USD",
        "rows": [
          {
            "size_id": 3,
            "base_price": {
              "line_1": 2500,
              "line_2": 3000,
              "line_3": 3500
            },
            "letter_price": {
              "line_1": 400,
              "line_2": 450,
              "line_3": 500
            },
            "letter_price_by_position": null
          }
        ],
        "created_at": "2026-11-14T00:00:00Z",
        "updated_at": "2026-11-14T00:00:00Z"
      },
      "idempotent_replay": false
    }
  }
}
```

## Example: A tier id from another customiser (error)

Request:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "duplicate_customiser_font_tier",
    "arguments": {
      "customiser_id": 42,
      "font_tier_id": 999,
      "dry_run": true
    }
  }
}
```

Response:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "isError": true,
    "structuredContent": {
      "error": {
        "code": "resource_not_found",
        "title": "Resource not found",
        "detail": "The requested resource does not exist or does not belong to the authenticated store.",
        "recovery": "The identifier does not exist in this store. Use the matching list tool to rediscover a valid id."
      }
    }
  }
}
```