> ## Documentation Index > Fetch the complete documentation index at: https://docs.closient.com/llms.txt > Use this file to discover all available pages before exploring further. # Add hierarchy link > Add a child product to this GTIN's packaging hierarchy. ## OpenAPI ````yaml /openapi/openapi-products.json post /products/api/v1/products/{gtin}/hierarchy openapi: 3.1.0 info: title: Products API version: 1.0.0 description: > Look up, claim, and browse GTINs in the Closient product repository. ## Authentication All endpoints require an API key passed via the `X-API-Key` HTTP header, unless otherwise noted. ``` X-API-Key: csb__ ``` Generate API keys in **Settings > API Keys** in your dashboard, or via the Account API. Session-based (cookie) authentication is also accepted for browser-based access. ## Rate Limits | Tier | Requests / minute | Requests / day | |-------------|-------------------|----------------| | Default | 300 | 10,000 | | Custom | Contact us | Contact us | Rate-limit headers are included on every response so callers can self-throttle without hitting our 429s ("informed governor"): - `RateLimit-Policy` — every active window, e.g. `300;w=60, 10000;w=86400` - `RateLimit-Limit` — quota for the **most-restrictive** currently-active window - `RateLimit-Remaining` — requests left in that window - `RateLimit-Reset` — seconds until that window resets (relative; clock-skew safe) Legacy `X-RateLimit-*` aliases are also emitted for back-compat. `X-RateLimit-Reset` keeps the absolute Unix-timestamp shape to avoid breaking existing consumers. When rate-limited, you receive `429 Too Many Requests` with a `retry_after_seconds` field in the error envelope and a `Retry-After` header. ## Pagination List endpoints return paginated results in this envelope: ```json { "data": [...], "pagination": { "page": 1, "page_size": 25, "total_count": 342, "total_pages": 14, "has_next": true, "has_previous": false } } ``` Use `?page=2&page_size=50` query parameters. Maximum page size is 100. ## Error Responses All errors conform to [RFC 9457 Problem Details](https://www.rfc-editor.org/rfc/rfc9457) with `Content-Type: application/problem+json`: ```json { "type": "https://closient.com/docs/errors/not_found", "title": "Not Found", "status": 404, "detail": "The requested resource was not found.", "error_code": "not_found", "retryable": false, "timestamp": "2026-03-31T12:00:00+00:00" } ``` Common error codes: `unauthorized` (401), `forbidden` (403), `not_found` (404), `validation_error` (422), `rate_limited` (429), `internal_error` (500). termsOfService: https://www.closient.com/terms/ servers: - url: https://www.closient.com security: [] tags: - name: Products description: Look up, claim, and browse products and trade items. - name: Product Group description: Manage GDSN packaging hierarchy relationships. - name: Import description: Bulk import products from CSV files. - name: QR description: Generate QR codes encoding GS1 Digital Link URLs. - name: Codes description: Generate GS1 DataMatrix and 1D barcodes (EAN/UPC/ITF-14/Code128). - name: Digital Link description: >- Parse GS1 Digital Link URIs into structured AIs (GTIN, lot, expiry, serial). - name: Labels description: >- Bulk label-export jobs: ZIPs of QR / DataMatrix / 1D symbols and multi-up sheet PDFs, async via Celery with status polling. externalDocs: description: Closient Documentation url: https://docs.closient.com paths: /products/api/v1/products/{gtin}/hierarchy: post: tags: - Product Group summary: Add hierarchy link description: Add a child product to this GTIN's packaging hierarchy. operationId: apps_products_api_hierarchy_api_create_hierarchy parameters: - in: path name: gtin schema: description: GTIN barcode of the parent product. title: Gtin type: string required: true description: GTIN barcode of the parent product. requestBody: content: application/json: schema: $ref: '#/components/schemas/HierarchyIn' required: true responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/HierarchyOut' security: - APIKeyHeaderAuth: [] - OAuthTokenAuth: [] - SessionAuth: [] components: schemas: HierarchyIn: examples: - child_gtin: '00012345678905' hierarchy_level: CASE quantity: 12 properties: child_gtin: description: GTIN of the child product to link. title: Child Gtin type: string quantity: description: Number of child items contained in the parent. title: Quantity type: integer hierarchy_level: $ref: '#/components/schemas/HierarchyLevelEnum' description: GDSN packaging level. required: - child_gtin - quantity - hierarchy_level title: HierarchyIn type: object HierarchyOut: examples: - child_gtin: '00012345678905' child_product_name: Acme Trail Mix 12oz hierarchy_level: CASE id: a1b2c3d4-e5f6-7890-abcd-ef1234567890 parent_gtin: '10012345678902' quantity: 12 properties: id: description: >- URL-safe 22-character shortuuid encoding of the row's UUID primary key. Stable across the row's lifetime; suitable for sharing in URLs, log lines, and external SDK clients. Accepted on input as either the shortuuid form or the canonical UUID form (``xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx``). format: shortuuid maxLength: 22 minLength: 22 pattern: ^[23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz]{22}$ title: Id type: string parent_gtin: description: Parent product GTIN. title: Parent Gtin type: string child_gtin: description: Child product GTIN. title: Child Gtin type: string child_product_name: description: Product name of the child product. title: Child Product Name type: string quantity: description: Number of child items in the parent packaging. title: Quantity type: integer hierarchy_level: $ref: '#/components/schemas/HierarchyLevelEnum' description: GDSN packaging level. required: - id - parent_gtin - child_gtin - child_product_name - quantity - hierarchy_level title: HierarchyOut type: object HierarchyLevelEnum: enum: - UNIT - INNER_PACK - CASE - PALLET title: HierarchyLevelEnum type: string securitySchemes: APIKeyHeaderAuth: type: apiKey in: header name: X-API-Key OAuthTokenAuth: type: http scheme: bearer SessionAuth: type: apiKey in: cookie name: sessionid ````