> ## 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. # Remove an image background > Creates a new PNG asset with the main subject isolated on a transparent background, derived from a ready PNG, JPEG, WebP, GIF, or AVIF image of the same website. The source is unchanged; the result carries `sourceAssetId`, its own `colors` and `transparentShare`, the source category, and a description naming the source. Soft shadows and reflections are removed; `trim` crops to the subject bounds. Not billed to credits; limited to 10,000 per organization per calendar month. MCP clients that render images also receive the result. ## OpenAPI ````yaml /api-reference/openapi.json post /websiteAssets/{assetId}/removeBackground 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: /websiteAssets/{assetId}/removeBackground: post: tags: - Assets summary: Remove an image background description: >- Creates a new PNG asset with the main subject isolated on a transparent background, derived from a ready PNG, JPEG, WebP, GIF, or AVIF image of the same website. The source is unchanged; the result carries `sourceAssetId`, its own `colors` and `transparentShare`, the source category, and a description naming the source. Soft shadows and reflections are removed; `trim` crops to the subject bounds. Not billed to credits; limited to 10,000 per organization per calendar month. MCP clients that render images also receive the result. operationId: websiteAssets.removeBackground parameters: - name: assetId in: path required: true schema: type: string minLength: 1 requestBody: required: false content: application/json: schema: type: object properties: trim: default: false description: >- Crop the result to the subject bounds instead of keeping the source dimensions. type: boolean responses: '200': description: The new transparent asset with its public CDN delivery URLs. content: application/json: schema: type: object properties: id: type: string description: >- Unique asset id. Pass it to websiteAssets.get and websiteAssets.delete. kind: type: string enum: - image - file description: >- Asset kind. Each kind has its own MIME allowlist and size limit. filename: type: string description: Original filename supplied at upload (1–255 characters). mimeType: type: string description: MIME type stored for the asset after upload normalization. description: anyOf: - type: string - type: 'null' description: >- One-line description supplied at upload, edited later, or generated for dashboard uploads. `null` when absent. category: anyOf: - type: string enum: - logo - icon - photo - illustration - screenshot - graphic - background - other - type: 'null' description: >- Image category: logo, icon, photo, illustration, screenshot, graphic, background, or other. `null` for files and unclassified images. byteSize: type: integer description: Exact file size in bytes. width: anyOf: - type: integer - type: 'null' description: >- Intrinsic pixel width, recorded at finalize for images. `null` for non-images and formats whose dimensions cannot be read. height: anyOf: - type: integer - type: 'null' description: Intrinsic pixel height; see `width`. colors: anyOf: - maxItems: 8 type: array items: type: object properties: hex: type: string description: Uppercase sRGB hex, exact for flat colors. share: anyOf: - type: number minimum: 0 maximum: 1 - type: 'null' description: >- Fraction of opaque pixels this color and its anti-aliasing cover. `null` for SVG, whose colors are read from the source instead of rendered. accent: type: boolean description: >- Saturated enough to matter as an accent even at a small share. required: - hex - share - accent additionalProperties: false description: >- Up to 8 representative colors sorted by share. `null` for files and for images that could not be analyzed. - type: 'null' transparentShare: anyOf: - type: number minimum: 0 maximum: 1 - type: 'null' description: >- Fraction of the backdrop that shows through, weighting each pixel by its transparency: 0 for an opaque image, roughly the background area for a cutout, 0.5 for a uniform 50% overlay. `null` when unknown. translucentShare: anyOf: - type: number minimum: 0 maximum: 1 - type: 'null' description: >- Fraction of pixels with partial alpha (soft shadows, glows, fades, glass), excluding fully transparent and fully opaque pixels. `null` when unknown. sourceAssetId: anyOf: - type: string - type: 'null' description: >- For a background-removed image, the id of the asset it was derived from. url: type: string description: >- Optimized public CDN URL for display. Transformable images use the 1920px default variant; other assets use `originalUrl`. originalUrl: type: string description: >- Stable public CDN URL for the original bytes. It never expires. previewUrl: anyOf: - type: string - type: 'null' description: >- For SVG images, the stable public CDN URL of a rasterized PNG preview (longest edge 1024px) that image models, MCP previews, and favicon fallbacks use. `null` for other assets and for SVGs that could not be rendered. srcSet: anyOf: - type: string - type: 'null' description: >- Ready-to-use responsive image srcset. `null` when image transformation is unavailable. variants: type: object propertyNames: type: string additionalProperties: type: string description: >- Optimized image URLs keyed by pixel width. Empty when image transformation is unavailable. createdAt: description: When the upload was started. type: string format: date-time status: type: string enum: - pending - ready description: >- `pending` until websiteAssets.finalize confirms the upload; `ready` once the asset is servable. required: - id - kind - filename - mimeType - description - category - byteSize - width - height - colors - transparentShare - translucentShare - sourceAssetId - url - originalUrl - previewUrl - srcSet - variants - createdAt - status 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' '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. ````