# Get customiser option (`get_customiser_option`)

Reads one record of one customiser option family in full: every configured field for its family, and the asset slots it owns with their current public URLs. This is the call to make before an update, because the update tool takes a merge patch and needs the current values. It requires the customisers:read scope, has no side effects and is safe to retry.

- Source URL: https://www.signcustomiser.com/help/mcp/tools/get_customiser_option/
- Markdown URL: https://www.signcustomiser.com/help/mcp/tools/get_customiser_option.md
- MCP endpoint: https://web.signcustomiser.com/mcp
- Required scope: `customisers:read`
- Behaviour: read

## Purpose

Read the current values of one option record before patching it, and see which of its asset slots are filled.

## Annotations

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

## Prerequisites

- A record id from list_customiser_options.
- letter_type_id for the letter_part and letter_part_colour families, and letter_part as well for letter_part_colour.
- A merchant has connected this store and approved the customisers:read scope.

## Arguments

| Property | Type | Required | Description |
| --- | --- | --- | --- |
| `customiser_id` | integer | yes | The customiser id, from list_customisers. |
| `option_type` | string | yes | Which option family the record belongs to. One of: `backboard`, `backlight`, `colour`, `extra`, `font`, `form`, `icon`, `jacket`, `letter_type`, `letter_part`, `letter_part_colour`, `material`, `mounting`, `mounting_colour`, `preset`, `size`, `support_finish`, `legacy_fixed_height_size`. |
| `option_id` | integer or string | yes | The record identifier from list_customiser_options: an integer for every family except letter_part, which is addressed by its catalogue name such as face or halo. |
| `letter_type_id` | integer | no | The letter type that owns the record, required for the letter_part and letter_part_colour families. |
| `letter_part` | string | no | The letter part that owns the colour, required for the letter_part_colour family. One of: `face`, `back`, `side`, `top`, `bottom`, `left`, `right`, `halo`, `trim`, `tube`. |

## Result

One option record and its filled asset slots. Bounded to one record; no nested collections beyond the record own fields.

| Property | Type | Required | Description |
| --- | --- | --- | --- |
| `request_id` | string | yes |  |
| `store` | object | yes |  |
| `store.id` | integer | yes |  |
| `store.name` | string | yes |  |
| `customiser_id` | integer | yes |  |
| `option_type` | string | yes | One of: `backboard`, `backlight`, `colour`, `extra`, `font`, `form`, `icon`, `jacket`, `letter_type`, `letter_part`, `letter_part_colour`, `material`, `mounting`, `mounting_colour`, `preset`, `size`, `support_finish`, `legacy_fixed_height_size`. |
| `option` | object | yes | The record, with the field names the public API publishes for its family. |
| `images` | array of object | yes | The record filled asset slots. A slot the family offers but nothing is stored in is omitted, so an empty list means the record carries no assets. |
| `images[].slot` | string | yes |  |
| `images[].url` | string | yes |  |

## Error cases

| Code | Recovery |
| --- | --- |
| `insufficient_scope` | The connection was approved without customisers:read. |
| `resource_not_found` | No record with that id exists in that family of that customiser. Call list_customiser_options to rediscover a valid id. |
| `validation_failed` | option_type is not a family name, option_id is the wrong kind of identifier for that family, or a nested family was called without letter_type_id or letter_part. |

## Example: Read one colour

Request:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_customiser_option",
    "arguments": {
      "customiser_id": 42,
      "option_type": "colour",
      "option_id": 7
    }
  }
}
```

Response:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "structuredContent": {
      "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t",
      "store": {
        "id": 12,
        "name": "Demo Signs"
      },
      "customiser_id": 42,
      "option_type": "colour",
      "option": {
        "id": 7,
        "name": "Warm White",
        "colour_type": "single",
        "hexcode": "#FFEEDD",
        "sort_order": 1,
        "base_price": 0,
        "currency": "USD",
        "image_url": "https://assets.signcustomiser.com/colours/7.png"
      },
      "images": [
        {
          "slot": "image",
          "url": "https://assets.signcustomiser.com/colours/7.png"
        }
      ]
    }
  }
}
```

## Example: A letter part addressed with an integer (error)

Request:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_customiser_option",
    "arguments": {
      "customiser_id": 42,
      "option_type": "letter_part",
      "letter_type_id": 18,
      "option_id": 4
    }
  }
}
```

Response:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "isError": true,
    "structuredContent": {
      "error": {
        "code": "validation_failed",
        "title": "Validation failed",
        "detail": "The selected option id is invalid.",
        "recovery": "Correct every field listed in errors, using its pointer to locate the value and allowed_values where one is given, then call the tool again.",
        "pointer": "/option_id",
        "allowed_values": [
          "face",
          "back",
          "side",
          "top",
          "bottom",
          "left",
          "right",
          "halo",
          "trim",
          "tube"
        ]
      }
    }
  }
}
```