> ## Documentation Index > Fetch the complete documentation index at: https://docs.base44.com/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Internal links on these pages omit the .md extension. Append .md to a docs page URL, or send an Accept: text/markdown header, to get that page as markdown. # Create asset > This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production. Adds a file that's already online to the app's media library, by its URL. Base44 doesn't download the file. To store a file with Base44, use [Upload asset](/api-reference/upload-asset) instead. In this response, `created_date` and `updated_date` include a `+00:00` offset. [List assets](/api-reference/list-assets) returns them without one. This endpoint is limited to 120 requests per minute, shared with Create asset, Rename asset and Delete asset. Some workspaces have a different limit. This endpoint accepts a personal API key belonging to a user with editor access to the app. A read-only key is refused, and workspace API keys are not accepted. The response includes fields beyond the ones documented here. Don't rely on undocumented response fields, as they can change at any time. Send only the fields documented here. Other request fields are not supported and their behavior can change. ## OpenAPI ````yaml /developers/references/app-management/app-management-openapi.json post /api/apps/{app_id}/assets openapi: 3.1.0 info: title: Base44 App Management API version: 1.0.0 servers: - url: https://app.base44.com security: - PersonalAccessTokenAuth: [] paths: /api/apps/{app_id}/assets: post: summary: Create asset description: >- This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production. Adds a file that's already online to the app's media library, by its URL. Base44 doesn't download the file. To store a file with Base44, use [Upload asset](/api-reference/upload-asset) instead. In this response, `created_date` and `updated_date` include a `+00:00` offset. [List assets](/api-reference/list-assets) returns them without one. This endpoint is limited to 120 requests per minute, shared with Create asset, Rename asset and Delete asset. Some workspaces have a different limit. This endpoint accepts a personal API key belonging to a user with editor access to the app. A read-only key is refused, and workspace API keys are not accepted. The response includes fields beyond the ones documented here. Don't rely on undocumented response fields, as they can change at any time. Send only the fields documented here. Other request fields are not supported and their behavior can change. operationId: create_asset_api_apps__app_id__assets_post parameters: - name: app_id in: path required: true schema: type: string description: ID of the app whose media library to change. title: App Id description: ID of the app whose media library to change. example: 6820f3a4e7b91d003c45a1f2 requestBody: required: true content: application/json: schema: properties: file_name: description: >- Name of the file. Characters other than letters, digits, `_`, `.` and `-` become `_`, anything up to the last `/` is dropped, and an empty name becomes `untitled`. example: Logo-dark.png title: File Name type: string file_url: description: >- Public `http` or `https` URL of the file. Base44 doesn't download or copy it, so the asset stays a link to this URL. Addresses on private networks and Base44's own hosts, other than its media CDN, are refused. example: >- https://media.base44.com/files/public/6820f3a4e7b91d003c45a1f2/Logo-dark.png title: File Url type: string source_type: default: upload description: >- How the file got into the library, `upload` or `generated`. Defaults to `upload`. enum: - upload - generated example: upload title: Source Type type: string file_type: anyOf: - type: string - type: 'null' description: >- File extension without the dot, such as `png`. Stored as you send it, and used by the `file_type` filter in List assets. Leave it out to store `null`. example: png title: File Type required: - file_name - file_url title: CreateAsset type: object example: file_name: Logo-dark.png file_url: https://cdn.acme.com/brand/Logo-dark.png file_type: png responses: '200': description: The new asset. content: application/json: schema: $ref: '#/components/schemas/AssetSummary' '400': description: >- `file_url` isn't an `http` or `https` URL, or points to an address that isn't allowed. '401': description: Missing or invalid credentials. '403': description: >- You don't have editor access to this app, the app is blocked, your API key is read-only, or you used a workspace API key. '404': description: App not found. '422': description: >- `file_name` or `file_url` is missing, or `source_type` isn't `upload` or `generated`. '429': description: >- Rate limit exceeded. The base limit is 120 requests per minute. See [Rate limits](/developers/references/apps-api/get-started/rate-limits) for the multiplier your plan gets. components: schemas: AssetSummary: properties: id: type: string title: Id description: ID of the asset. example: 68b0e1f2a3c4d5e6f7a8b9c0 app_id: type: string title: App Id description: ID of the app the asset belongs to. example: 6820f3a4e7b91d003c45a1f2 file_name: type: string title: File Name description: Name of the file. example: Logo-dark.png file_url: type: string title: File Url description: URL of the file. example: >- https://media.base44.com/files/public/6820f3a4e7b91d003c45a1f2/Logo-dark.png source_type: type: string enum: - upload - generated title: Source Type description: >- How the file got into the library. `upload` for a file someone uploaded, and `generated` for most files Base44 created for the app, such as AI-generated images and videos or a Figma import. example: upload file_type: anyOf: - type: string - type: 'null' title: File Type description: >- File extension without the dot, usually lowercase, such as `png` or `mp4`. The value is `null` when the file was added without one. example: png created_date: type: string title: Created Date description: >- When the asset was added to the library, as a UTC timestamp in ISO 8601 format. example: '2026-01-15T09:23:41' updated_date: type: string title: Updated Date description: >- When the asset was last changed, such as renamed, as a UTC timestamp in ISO 8601 format. example: '2026-01-15T09:31:07' type: object required: - id - app_id - file_name - file_url - source_type - file_type - created_date - updated_date title: AssetSummary description: A file in the app's media library. securitySchemes: PersonalAccessTokenAuth: type: http scheme: bearer description: 'Personal access token, sent as `Authorization: Bearer `.' ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.