Customiser letter types

Update a letter type

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Applies an RFC 7396 JSON Merge Patch to one letter type: properties omitted from the body are unchanged, and null clears a nullable property (description, shape). letter_parts is an array and is replaced wholesale. Read-only and unknown fields are rejected — sending one at all is a 422, whatever its value.

PATCH/api/v3/customisers/{customiser_id}/letter-types/{letter_type_id}

Update a letter type

Applies an RFC 7396 JSON Merge Patch to one letter type: properties omitted from the body are unchanged, and `null` clears a nullable property (`description`, `shape`). `letter_parts` is an array and is replaced wholesale. Read-only and unknown fields are rejected — sending one at all is a 422, whatever its value. An empty object `{}` is a valid no-op. The patched result must still be renderable, so a patch that would leave no active letter part, clear a lightbox letter type's shape, or set a shape on any other category is refused. Requires `customisers:write`. An `Idempotency-Key` is optional here: sending one makes the update safe to retry (an exact repeat replays the original response; the same key with a different body is a 409). The update clears the customiser's cached storefront configuration and runs the advisory language sync, and never regenerates Shopify products, product images, or the product cache. Dropping a part from `letter_parts` does not delete the colour selection that part already carries — it stops the customiser offering it, and releases the guard that would otherwise refuse the letter-part delete.

Update a letter type

Overview

An empty object {} is a valid no-op. The patched result must still be renderable, so a patch that would leave no active letter part, clear a lightbox letter type's shape, or set a shape on any other category is refused. Requires customisers:write. An Idempotency-Key is optional here: sending one makes the update safe to retry (an exact repeat replays the original response; the same key with a different body is a 409). The update clears the customiser's cached storefront configuration and runs the advisory language sync, and never regenerates Shopify products, product images, or the product cache. Dropping a part from letter_parts does not delete the colour selection that part already carries — it stops the customiser offering it, and releases the guard that would otherwise refuse the letter-part delete.

Authorisation

Bearer token required. Include it in theAuthorization header.

Required scope: customisers:write

Path parameters

customiser_idstringpathrequired

The customiser id.

Example: 1

letter_type_idstringpathrequired

The letter type id.

Example: 7

Request body

shapestringbody

letter_partsarraybody

price_multiplier_targetstringbody

namestringbody

descriptionstringbody

base_priceintegerbody

price_multipliernumberbody

Request body example

{
  "shape": "rectangle",
  "letter_parts": [
    {
      "letter_part": "face",
      "active": true
    }
  ],
  "price_multiplier_target": "base_letter_price",
  "name": "Front lit",
  "description": "Light through the face",
  "base_price": 500,
  "price_multiplier": 1.2
}

Update a letter type

curl https://web.signcustomiser.com/api/v3/customisers/1/letter-types/7 \
  --request PATCH \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_TOKEN' \
  --header 'Content-Type: application/json' \
  --data '{
  "shape": "rectangle",
  "letter_parts": [
    {
      "letter_part": "face",
      "active": true
    }
  ],
  "price_multiplier_target": "base_letter_price",
  "name": "Front lit",
  "description": "Light through the face",
  "base_price": 500,
  "price_multiplier": 1.2
}'

{
  "data": {
    "object": "letter_type",
    "id": 7,
    "customiser_id": 42,
    "name": "Front lit",
    "description": "Light through the face",
    "shape": null,
    "letter_parts": [
      {
        "letter_part": "face",
        "active": true
      }
    ],
    "base_price": 500,
    "currency": "USD",
    "price_multiplier": 1,
    "price_multiplier_target": "base_letter_price",
    "sort_order": 1,
    "image_url": null,
    "created_at": "2026-08-13T00:00:00Z",
    "updated_at": "2026-08-13T00:05:00Z"
  },
  "links": {
    "self": "https://web.signcustomiser.com/api/v3/customisers/42/letter-types/7",
    "documentation": "https://www.signcustomiser.com/help/api/"
  },
  "meta": {
    "api_version": "v3",
    "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
  }
}

{
  "type": "https://www.signcustomiser.com/help/api/problems/malformed_json",
  "title": "Malformed JSON",
  "status": 400,
  "code": "malformed_json",
  "detail": "The request body is not valid JSON: Syntax error.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}

{
  "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"
}

{
  "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"
}

{
  "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"
}

{
  "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"
}

{
  "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"
}

{
  "type": "https://www.signcustomiser.com/help/api/problems/validation_failed",
  "title": "Validation failed",
  "status": 422,
  "code": "validation_failed",
  "detail": "The request payload failed validation.",
  "errors": [
    {
      "pointer": "/sort_order",
      "code": "prohibited",
      "detail": "The sort order field is prohibited."
    }
  ],
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}

{
  "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"
}