> ## Documentation Index > Fetch the complete documentation index at: https://cactal.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Update an item > Patches an item; omitted fields are left untouched. Keys in `data` are merged into the existing values and validated the same way as on create, while each key provided in `references`, `images`, or `files` replaces that field’s value wholesale — pass `null` (or `[]` for multi-valued fields) to clear an optional field. `slug` renames the item’s slug; slug and unique-field collisions fail with a conflict. Pass `position: "first"` or `"last"`, or `"before"` / `"after"` together with `anchorItemId`, to move the item within the collection’s manual order — the default sort for item lists. ## OpenAPI ````yaml /api-reference/openapi.json patch /cms/items/{itemId} openapi: 3.1.0 info: title: Cactal API version: 1.0.0 description: >- The Cactal public API. Create, edit, publish, and operate websites programmatically. Authenticate every request with an API key sent as `Authorization: Bearer `. servers: - url: https://api.cactal.ai/v1 security: - apiKey: [] tags: - name: Documentation description: >- Search and read the Cactal product documentation for concepts, guides, agent workflows, platform behavior, and API operations. - name: Feedback description: >- Submit free-form product feedback from users and agents to the Cactal feedback inbox. - name: Websites description: >- Create and manage websites — the top-level resource that owns source code, content, assets, domains, and analytics. - name: Website editors description: >- Grant, list, and revoke website-scoped editor access, and invite collaborators to a single website by email. - name: API keys description: >- Create, scope, rotate, and revoke the API keys that authenticate programmatic and agent access. - name: Source code description: >- Read and edit the framework source files of a website draft. Mutations require an edit lease. - name: Publishing description: Validate, build, publish, and roll back website versions. - name: CMS collections description: >- Define the content model: collections of structured content owned by a website. - name: CMS fields description: Manage the typed fields that make up a collection schema. - name: CMS items description: >- Create, query, publish, and organize the content entries inside a collection. - name: Domains description: >- Manage platform subdomains and custom domains, including DNS verification and the primary domain. - name: Assets description: Upload and manage website files and images served from the Cactal CDN. - name: Media generation description: >- Generate reference-guided website images that are stored as ordinary Cactal CDN assets. - name: Project Context description: >- Upload private durable reference material that the website agent can search, read, and inspect. - name: Analytics description: >- Read first-party traffic analytics for a website and export datasets as CSV. - name: Organizations description: Manage organizations, members, and organization-wide invitations. - name: Audit log description: >- Read the immutable record of actions performed in an organization by users and API keys. - name: Billing description: >- Read billing state and manage plans, site capacity, and prepaid usage balance. Every billing operation requires the organization owner role, which API keys cannot hold — today these operations are performed from the dashboard, return 403 for API-key callers, and are hidden from MCP tool lists. paths: /cms/items/{itemId}: patch: tags: - CMS items summary: Update an item description: >- Patches an item; omitted fields are left untouched. Keys in `data` are merged into the existing values and validated the same way as on create, while each key provided in `references`, `images`, or `files` replaces that field’s value wholesale — pass `null` (or `[]` for multi-valued fields) to clear an optional field. `slug` renames the item’s slug; slug and unique-field collisions fail with a conflict. Pass `position: "first"` or `"last"`, or `"before"` / `"after"` together with `anchorItemId`, to move the item within the collection’s manual order — the default sort for item lists. operationId: cms.items.update parameters: - name: itemId in: path required: true schema: type: string minLength: 1 requestBody: required: false content: application/json: schema: type: object properties: slug: description: >- New slug for the item — a rename. Omit to keep the current slug. Must be unique among the collection’s active items. type: string pattern: ^[a-z0-9][a-z0-9-]{0,255}$ data: type: object propertyNames: type: string additionalProperties: {} references: type: object propertyNames: type: string additionalProperties: anyOf: - type: string minLength: 1 - maxItems: 1000 type: array items: type: string minLength: 1 - type: 'null' images: type: object propertyNames: type: string additionalProperties: anyOf: - anyOf: - type: string minLength: 1 - type: object properties: assetId: type: string minLength: 1 altText: anyOf: - type: string maxLength: 2000 - type: 'null' required: - assetId additionalProperties: false - maxItems: 25 type: array items: anyOf: - type: string minLength: 1 - type: object properties: assetId: type: string minLength: 1 altText: anyOf: - type: string maxLength: 2000 - type: 'null' required: - assetId additionalProperties: false - type: 'null' files: type: object propertyNames: type: string additionalProperties: anyOf: - anyOf: - type: string minLength: 1 - type: object properties: assetId: type: string minLength: 1 required: - assetId - type: 'null' position: description: >- Moves the item within the collection’s manual order — the default sort for item lists. Omit to leave the order unchanged. `"before"` / `"after"` require `anchorItemId`. type: string enum: - before - after - first - last anchorItemId: description: >- Sibling item to move against when `position` is `"before"` or `"after"`. type: string minLength: 1 responses: '200': description: >- Identity and ordering key of the updated item. Read the full item back with the get-item endpoint. content: application/json: schema: type: object properties: id: type: string description: Id of the updated item. slug: type: string description: Slug of the item after the update. position: type: string description: >- The item’s fractional ordering key after the update; changes when `position` is used. The default list order sorts by this value. required: - id - slug - position additionalProperties: false '400': description: >- Validation failed. The response `message` names the first invalid field. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '401': description: Missing, invalid, expired, or revoked API key. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '403': description: The authenticated principal lacks the required capability. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '404': description: >- The resource does not exist or is outside the principal’s access scope. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '409': description: The request conflicts with the current state of the resource. content: application/json: schema: $ref: '#/components/schemas/ServiceError' '429': description: >- Rate limit exceeded. Retry after the number of seconds in the `Retry-After` header. content: application/json: schema: $ref: '#/components/schemas/ServiceError' components: schemas: ServiceError: type: object required: - kind - message description: >- Canonical error body returned by every non-2xx response. Extra fields carry error-specific details. properties: kind: type: string enum: - validation - unauthorized - forbidden - not_found - conflict - rate_limited - internal description: Stable, machine-readable error category. message: type: string description: Human-readable explanation of the failure. suggestion: type: string description: >- What to do next when the failure has a known fix; may name the exact operation to call. validValues: type: array items: type: string description: The acceptable values for the failing field, when the set is closed. additionalProperties: true securitySchemes: apiKey: type: http scheme: bearer description: >- Cactal API key. Create one in the dashboard or via `POST /apiKeys`. The plaintext key is shown once at creation. ````