> ## Documentation Index > Fetch the complete documentation index at: https://docs.tryordinal.com/llms.txt > Use this file to discover all available pages before exploring further. # Prepare a local file upload > Creates an upload job and returns signed credentials so you can POST a local file directly to the returned `uploadUrl`. After preparing, POST the file to `uploadUrl` as multipart form data with the returned `params`, `signature`, and `file` fields, then poll `GET /uploads/{id}` until status is `ready`. See [File uploads](/api/file-uploads#local-file-upload) for a full walkthrough and curl examples. **Supported file types:** - Images: JPEG, PNG, GIF, WebP - Videos: MP4, QuickTime (MOV) **File size limits:** - Images: 10 MB max - GIFs: 15 MB max - Videos: 350 MB max The returned credentials are short-lived. Upload the file before `expiresAt`. ## OpenAPI ````yaml /api/openapi.json post /uploads/prepare openapi: 3.1.0 info: title: Ordinal API version: 1.0.0 description: API to create and manage Ordinal workspaces, posts, profiles, and analytics servers: - url: https://app.tryordinal.com/api/v1 description: Production server security: - bearerAuth: [] tags: - name: Analytics description: Social media analytics data - name: Approvals description: Post approval workflows - name: Comments description: >- Post comments for team collaboration. Supports @mentions using the format @[Display Name](userId). - name: Engagements description: Auto-engagements for posts (likes, comments, reposts) - name: Invites description: Workspace invitations for adding new users - name: Labels description: Labels for organizing posts - name: Instagram description: Instagram utilities for location search and tagging - name: LinkedIn description: LinkedIn utilities for profile lookups, tagging, and mentions - name: Posts description: Create and manage posts - name: Profiles description: List connected social profiles - name: Slack Boosts description: >- List connected Slack channels (webhooks), then create and manage slack boosts so teams get notified in Slack when posts publish. Requires Slack connected with marketing boost channels. - name: Subscribers description: Post subscribers for notifications - name: File Uploads description: >- Upload files from URLs for use in posts. Supports images (JPEG, PNG, GIF, WebP) up to 10 MB and videos (MP4, MOV) up to 350 MB. - name: Ideas description: >- Create and manage content ideas. Ideas are draft posts without scheduled dates that can be converted to calendar posts. - name: Inline Comments description: >- Text-anchored comments on specific post content. Read-only API for retrieving inline comments across channels. - name: Users description: Workspace users - name: Webhooks description: >- Create, list, get, update, and delete webhooks to receive real-time event notifications - name: Workspaces description: Workspace information paths: /uploads/prepare: post: tags: - File Uploads summary: Prepare a local file upload description: >- Creates an upload job and returns signed credentials so you can POST a local file directly to the returned `uploadUrl`. After preparing, POST the file to `uploadUrl` as multipart form data with the returned `params`, `signature`, and `file` fields, then poll `GET /uploads/{id}` until status is `ready`. See [File uploads](/api/file-uploads#local-file-upload) for a full walkthrough and curl examples. **Supported file types:** - Images: JPEG, PNG, GIF, WebP - Videos: MP4, QuickTime (MOV) **File size limits:** - Images: 10 MB max - GIFs: 15 MB max - Videos: 350 MB max The returned credentials are short-lived. Upload the file before `expiresAt`. operationId: uploads-prepare requestBody: required: true content: application/json: schema: type: object required: - filename - mimetype - size properties: filename: type: string minLength: 1 description: Original filename, including extension. mimetype: type: string minLength: 1 description: MIME type of the file (e.g., image/jpeg, video/mp4). size: type: integer exclusiveMinimum: 0 description: File size in bytes. additionalProperties: false example: filename: product-photo.jpg mimetype: image/jpeg size: 245678 responses: '200': description: Signed credentials for uploading the file content: application/json: schema: $ref: '#/components/schemas/UploadPrepared' example: id: 550e8400-e29b-41d4-a716-446655440000 status: awaiting_upload uploadUrl: https://upload.example.com params: '{"auth":{...},"template_id":"..."}' signature: sha384:... expiresAt: '2026-02-04T11:30:00.000Z' createdAt: '2026-02-04T10:30:00.000Z' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '429': $ref: '#/components/responses/RateLimited' components: schemas: UploadPrepared: type: object description: >- Response when a local file upload is prepared. Use `uploadUrl`, `params`, and `signature` to POST the file. See [File uploads](/api/file-uploads#local-file-upload) for the full multipart upload example. properties: id: type: string format: uuid description: Upload job ID. Use this to poll GET /uploads/{id}. status: type: string enum: - awaiting_upload description: Initial status while Ordinal waits for the file POST. uploadUrl: type: string format: uri description: URL to POST the file to as multipart form data. params: type: string description: Signed upload params. Include verbatim as the `params` form field. signature: type: string description: >- Signature for the params. Include verbatim as the `signature` form field. expiresAt: type: string format: date-time description: Time after which the signed credentials are no longer valid. createdAt: type: string format: date-time required: - id - status - uploadUrl - params - signature - expiresAt - createdAt ValidationError: type: object properties: code: type: string message: type: string data: type: object properties: errors: type: object additionalProperties: type: array items: type: string Error: type: object properties: code: type: string message: type: string responses: BadRequest: description: Bad Request - Invalid input parameters content: application/json: schema: $ref: '#/components/schemas/ValidationError' example: code: BAD_REQUEST message: Bad Request data: errors: publishAt: - Invalid date format status: - Invalid enum value Unauthorized: description: Unauthorized - Missing or invalid API key content: application/json: schema: $ref: '#/components/schemas/Error' example: code: UNAUTHORIZED message: Invalid or unauthorized API key RateLimited: description: Too Many Requests - Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/Error' example: code: TOO_MANY_REQUESTS message: >- Rate limit of 100 requests per 60s exceeded. Quota resets in 45 seconds securitySchemes: bearerAuth: type: http scheme: bearer description: >- API key authentication. Generate an API key from your workspace settings. ````