> ## 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. # Upload asset > This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production. Uploads a file to the app's media library. Send it as `multipart/form-data` in a field named `file`. The file name decides what's accepted. It must end in one of these extensions: `3g2`, `3gp`, `avi`, `csv`, `docx`, `fbx`, `gif`, `glb`, `gltf`, `ico`, `jpeg`, `jpg`, `json`, `m4v`, `md`, `mkv`, `mov`, `mp3`, `mp4`, `mtl`, `obj`, `ogv`, `pdf`, `png`, `svg`, `txt`, `wav`, `webm`, `webp`, `wmv`, `xlsx`, `zip`. HTML files aren't accepted. The size limit depends on the type, from 1 MB for `ico` to 100 MB for audio and video. Most images can be up to 40 MB. The asset's `file_name` is the uploaded file's name with the same character rules as [Create asset](/api-reference/create-asset), and its `file_type` is the extension, in lowercase. The file is stored at a public URL, returned in `file_url`, so anyone with the URL can open it. 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 60 requests per minute. 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. ## OpenAPI ````yaml /developers/references/app-management/app-management-openapi.json post /api/apps/{app_id}/assets/upload 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/upload: post: summary: Upload asset description: >- This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production. Uploads a file to the app's media library. Send it as `multipart/form-data` in a field named `file`. The file name decides what's accepted. It must end in one of these extensions: `3g2`, `3gp`, `avi`, `csv`, `docx`, `fbx`, `gif`, `glb`, `gltf`, `ico`, `jpeg`, `jpg`, `json`, `m4v`, `md`, `mkv`, `mov`, `mp3`, `mp4`, `mtl`, `obj`, `ogv`, `pdf`, `png`, `svg`, `txt`, `wav`, `webm`, `webp`, `wmv`, `xlsx`, `zip`. HTML files aren't accepted. The size limit depends on the type, from 1 MB for `ico` to 100 MB for audio and video. Most images can be up to 40 MB. The asset's `file_name` is the uploaded file's name with the same character rules as [Create asset](/api-reference/create-asset), and its `file_type` is the extension, in lowercase. The file is stored at a public URL, returned in `file_url`, so anyone with the URL can open it. 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 60 requests per minute. 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. operationId: upload_to_assets_api_apps__app_id__assets_upload_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: multipart/form-data: schema: $ref: '#/components/schemas/UploadAsset' responses: '200': description: The new asset. content: application/json: schema: $ref: '#/components/schemas/AssetSummary' '400': description: >- The file name has no supported extension, or the file is over the size limit for its type. '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` is missing.' '429': description: >- Rate limit exceeded. The base limit is 60 requests per minute. See [Rate limits](/developers/references/apps-api/get-started/rate-limits) for the multiplier your plan gets. components: schemas: UploadAsset: properties: file: type: string format: binary title: File description: >- The file to upload. Its name must end in one of the supported extensions. type: object required: - file title: UploadAsset 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.