# POST Create a support finish

Adds a support finish to the customiser, at the end of the current presentation order. `name` and `backboard_ids` are required — `backboard_ids` because a finish no backboard offers is unreachable in the storefront, and every id must be one of this customiser's backboards. Every other field has a documented default (`finish_kind` colour, `opacity` 1, `applied_to_visualisation` true, `min_size_rule` any, `base_price` 0, `price_multiplier` 1, `price_multiplier_target` base_letter_price). Image fields are read-only until the upload surface ships, `layers` is not writable, and `sort_order` moves only through the reorder operation — naming any of them is a 422. A finish must be renderable: a `colour` finish needs a `hexcode` (422 `colour_value_required`), and the `texture` kind is refused with a 422 `texture_image_required` until image upload ships. Requires `customisers:write` and an `Idempotency-Key`. The write clears the customiser's cached storefront configuration and runs the advisory language sync. It never regenerates Shopify products, product images, or the product cache, so live listings are untouched. Option writes also spend one unit of a separate per-key option-write budget; exhausting it returns a 429 with `retry_after`.

- Source URL: https://www.signcustomiser.com/help/api/v3-post-create-a-support-finish/
- Markdown URL: https://www.signcustomiser.com/help/api/v3-post-create-a-support-finish.md
- Group: Customiser support finishes
- Method: POST
- Path: /api/v3/customisers/{customiser_id}/support-finishes
- Auth: Bearer token
- Required scopes: `customisers:write`

## Path parameters

- customiser_id (string, required): The customiser id. Example: 1

## Body parameters

- finish_kind (string, optional): No description provided.
- min_size_rule (string, optional): No description provided.
- price_multiplier_target (string, optional): No description provided.
- name (string, optional): No description provided.
- description (string, optional): No description provided.
- hexcode (string, optional): No description provided.
- opacity (integer, optional): No description provided.
- applied_to_visualisation (boolean, optional): No description provided.
- backboard_ids (array, optional): No description provided.
- base_price (integer, optional): No description provided.
- price_multiplier (number, optional): No description provided.

## Request body example

```json
{
  "finish_kind": "colour",
  "min_size_rule": "any",
  "price_multiplier_target": "base_letter_price",
  "name": "Gloss Black",
  "description": "A deep gloss black",
  "hexcode": "#111111",
  "opacity": 1,
  "applied_to_visualisation": true,
  "backboard_ids": [
    11
  ],
  "base_price": 500,
  "price_multiplier": 1.2
}
```

## cURL example

```bash
curl https://web.signcustomiser.com/api/v3/customisers/1/support-finishes \
  --request POST \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_TOKEN' \
  --header 'Content-Type: application/json' \
  --data '{
  "finish_kind": "colour",
  "min_size_rule": "any",
  "price_multiplier_target": "base_letter_price",
  "name": "Gloss Black",
  "description": "A deep gloss black",
  "hexcode": "#111111",
  "opacity": 1,
  "applied_to_visualisation": true,
  "backboard_ids": [
    11
  ],
  "base_price": 500,
  "price_multiplier": 1.2
}'
```

## Response examples

### 201 POST 201 example 1

```json
{
  "data": {
    "object": "support_finish",
    "id": 27,
    "customiser_id": 42,
    "name": "Gloss Black",
    "description": null,
    "finish_kind": "colour",
    "hexcode": "#111111",
    "opacity": 1,
    "applied_to_visualisation": true,
    "backboard_ids": [
      11
    ],
    "min_width_cm": null,
    "min_height_cm": null,
    "min_size_rule": "any",
    "base_price": 0,
    "currency": "USD",
    "price_multiplier": 1,
    "price_multiplier_target": "base_letter_price",
    "sort_order": 1,
    "preview_image_url": null,
    "example_image_url": null,
    "texture_image_url": null,
    "created_at": "2026-08-13T00:00:00Z",
    "updated_at": "2026-08-13T00:00:00Z"
  },
  "links": {
    "self": "https://web.signcustomiser.com/api/v3/customisers/42/support-finishes/27",
    "documentation": "https://www.signcustomiser.com/help/api/"
  },
  "meta": {
    "api_version": "v3",
    "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
  }
}
```

### 400 Missing idempotency key

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/missing_idempotency_key",
  "title": "Missing idempotency key",
  "status": 400,
  "code": "missing_idempotency_key",
  "detail": "Provide an Idempotency-Key header for this write.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 401 Missing API key

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/missing_api_key",
  "title": "Missing API key",
  "status": 401,
  "code": "missing_api_key",
  "detail": "Provide a store API key as a bearer token.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 403 Insufficient scope

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/insufficient_scope",
  "title": "Insufficient scope",
  "status": 403,
  "code": "insufficient_scope",
  "detail": "This operation requires the customisers:write scope.",
  "required_scopes": [
    "customisers:write"
  ],
  "granted_scopes": [
    "customisers:read"
  ],
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 404 Unknown customiser

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/resource_not_found",
  "title": "Resource not found",
  "status": 404,
  "code": "resource_not_found",
  "detail": "The requested resource does not exist or does not belong to the authenticated store.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 409 Idempotency conflict

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/idempotency_key_conflict",
  "title": "Idempotency key conflict",
  "status": 409,
  "code": "idempotency_key_conflict",
  "detail": "This Idempotency-Key was already used for a different request body on this operation.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 413 Request body too large

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/request_too_large",
  "title": "Request too large",
  "status": 413,
  "code": "request_too_large",
  "detail": "The request body must not exceed 2 MiB.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 422 Unknown field

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/unknown_field",
  "title": "Unknown field",
  "status": 422,
  "code": "unknown_field",
  "detail": "The request contains fields this operation does not define: /material_type.",
  "errors": [
    {
      "pointer": "/material_type",
      "code": "unknown_field",
      "detail": "The field \"material_type\" is not supported by this operation."
    }
  ],
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 429 Option write budget exhausted

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/rate_limited",
  "title": "Too many requests",
  "status": 429,
  "code": "rate_limited",
  "detail": "You have exceeded the request limit for this API key.",
  "retry_after": 37,
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```