# POST Create a backboard

Adds a backboard to the customiser, at the end of the current presentation order. Only `name` is required; every other field has a documented default (`backboard_type` null, `letter_type_ids` empty, `allow_multilayer` false, `base_price` 0, `price_multiplier` 1, `price_multiplier_target` base_letter_price). On a channel customiser outside the cut-out family, `letter_type_ids` is required and must name at least one of the customiser's own letter types, because a backboard no letter type offers is unreachable in the storefront. Image fields, the uploaded shape and everything derived from it (`geometry`, `custom_shape`, `padding`), and the multilayer `layers` definitions are read-only until their own write surfaces ship, and `sort_order` moves only through the reorder operation — naming any of them is a 422. `backboard_type` cannot be set to `custom_shape` or `cutout` on a create for the same reason: those draw the board from an uploaded shape, and a create cannot supply one. 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-backboard/
- Markdown URL: https://www.signcustomiser.com/help/api/v3-post-create-a-backboard.md
- Group: Customiser backboards
- Method: POST
- Path: /api/v3/customisers/{customiser_id}/backboards
- Auth: Bearer token
- Required scopes: `customisers:write`

## Path parameters

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

## Body parameters

- backboard_type (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.
- letter_type_ids (array, optional): No description provided.
- outline_size (integer, optional): No description provided.
- allow_multilayer (boolean, optional): No description provided.
- custom_background_enabled (boolean, optional): No description provided.
- show_custom_background (boolean, optional): No description provided.
- base_price (integer, optional): No description provided.
- price_multiplier (number, optional): No description provided.
- price_per_sq_cm (number, optional): No description provided.

## Request body example

```json
{
  "backboard_type": "board",
  "price_multiplier_target": "base_letter_price",
  "name": "Clear Acrylic Panel",
  "description": "A 5mm clear acrylic panel",
  "letter_type_ids": [
    3
  ],
  "outline_size": 8,
  "allow_multilayer": false,
  "custom_background_enabled": false,
  "show_custom_background": false,
  "base_price": 500,
  "price_multiplier": 1.2,
  "price_per_sq_cm": 0.022
}
```

## cURL example

```bash
curl https://web.signcustomiser.com/api/v3/customisers/1/backboards \
  --request POST \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_TOKEN' \
  --header 'Content-Type: application/json' \
  --data '{
  "backboard_type": "board",
  "price_multiplier_target": "base_letter_price",
  "name": "Clear Acrylic Panel",
  "description": "A 5mm clear acrylic panel",
  "letter_type_ids": [
    3
  ],
  "outline_size": 8,
  "allow_multilayer": false,
  "custom_background_enabled": false,
  "show_custom_background": false,
  "base_price": 500,
  "price_multiplier": 1.2,
  "price_per_sq_cm": 0.022
}'
```

## Response examples

### 201 POST 201 example 1

```json
{
  "data": {
    "object": "backboard",
    "id": 11,
    "customiser_id": 42,
    "name": "Clear Acrylic Panel",
    "description": null,
    "backboard_type": "board",
    "letter_type_ids": [],
    "outline_size": null,
    "allow_multilayer": false,
    "custom_background_enabled": false,
    "show_custom_background": false,
    "base_price": 0,
    "currency": "USD",
    "price_multiplier": 1,
    "price_multiplier_target": "base_letter_price",
    "price_per_sq_cm": null,
    "sort_order": 1,
    "image_url": null,
    "button_image_url": null,
    "geometry": {
      "has_custom_shape": false,
      "status": null,
      "failure_reason": null,
      "measured_at": 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/backboards/11",
    "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 Shape upload required

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/validation_failed",
  "title": "Validation failed",
  "status": 422,
  "code": "validation_failed",
  "detail": "A custom_shape backboard is drawn from an uploaded shape, and this API cannot upload one yet.",
  "errors": [
    {
      "pointer": "/backboard_type",
      "code": "custom_shape_required",
      "detail": "A custom_shape backboard needs an uploaded shape, which this operation cannot supply."
    }
  ],
  "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"
}
```