> ## Documentation Index > Fetch the complete documentation index at: https://docs.trypost.it/llms.txt > Use this file to discover all available pages before exploring further. # Upload to signed URL > Receives a file at a one-time signed URL issued by the MCP `request-media-upload-tool`. No API key: the signature authorizes the request. Send the file as `multipart/form-data` in the `media` field, for example `curl -F media=@launch.jpg ""`. The URL works once, until it expires (15 minutes by default); a second upload to it returns `409`. The returned `upload_token` is then used as a media item, like a token from `POST /uploads`. Accepted files: JPEG, PNG, GIF and WebP images (HEIC and HEIF too when the server can convert them, stored as JPEG), MP4 and MOV videos, and PDF documents. Size caps: 10 MB per image (and at most about 67 megapixels, 8192 × 8192 pixels in total), 1 GB per video, 100 MB per PDF. Each network enforces its own, usually smaller, caps when the post is scheduled or published (`GET /content-types`). A file the server cannot read returns `422` with only `message`: `Unable to read uploaded file.` ## OpenAPI ````yaml /openapi.json post /uploads/{token} openapi: 3.1.0 info: title: TryPost API version: 2.0.0 description: >- REST API for TryPost. Authenticate with a workspace API key as a Bearer token. servers: - url: https://app.trypost.it/api description: TryPost Cloud security: - bearerAuth: [] tags: - name: Posts description: Create, read, update, delete and preview posts. - name: Post notes description: Internal notes on a post, visible to workspace members. - name: Approvals description: Approve or reject posts waiting for approval. - name: Recurrence description: Make a post repeat on a schedule. - name: Media and uploads description: Upload files and attach media to posts. - name: Social accounts description: Connected social accounts and their network-specific options. - name: Channels description: A channel's posting schedule and queue. - name: Ideas description: Ideas on the Create board. - name: Idea stages description: The groups (columns) of the ideas board. - name: Analytics description: Workspace and channel insights. - name: Labels description: Labels to organize posts and ideas. - name: Signatures description: Reusable text to append to posts. - name: Workspace description: The workspace the API key belongs to. - name: API keys description: Personal API keys for this workspace. - name: Webhooks description: Outgoing webhooks and their delivery logs. - name: Repurposes description: Automations that republish videos posted outside TryPost. - name: Platform description: Platform capabilities and content types. paths: /uploads/{token}: post: tags: - Media and uploads summary: Upload to signed URL description: >- Receives a file at a one-time signed URL issued by the MCP `request-media-upload-tool`. No API key: the signature authorizes the request. Send the file as `multipart/form-data` in the `media` field, for example `curl -F media=@launch.jpg ""`. The URL works once, until it expires (15 minutes by default); a second upload to it returns `409`. The returned `upload_token` is then used as a media item, like a token from `POST /uploads`. Accepted files: JPEG, PNG, GIF and WebP images (HEIC and HEIF too when the server can convert them, stored as JPEG), MP4 and MOV videos, and PDF documents. Size caps: 10 MB per image (and at most about 67 megapixels, 8192 × 8192 pixels in total), 1 GB per video, 100 MB per PDF. Each network enforces its own, usually smaller, caps when the post is scheduled or published (`GET /content-types`). A file the server cannot read returns `422` with only `message`: `Unable to read uploaded file.` operationId: uploadToSignedUrl parameters: - name: token in: path required: true description: Upload token from the signed URL. schema: type: string format: uuid example: 4f6c2b1e-8d3a-4e5f-9a7b-1c2d3e4f5a6b - name: workspace_id in: query required: true description: Part of the signed URL. schema: type: string format: uuid - name: expires in: query required: true description: Part of the signed URL (Unix timestamp). schema: type: integer - name: signature in: query required: true description: Part of the signed URL. schema: type: string requestBody: required: true content: multipart/form-data: schema: type: object required: - media properties: media: type: string format: binary description: The file. responses: '201': description: The stored file. content: application/json: schema: $ref: '#/components/schemas/SignedUpload' example: upload_token: 4f6c2b1e-8d3a-4e5f-9a7b-1c2d3e4f5a6b media_id: 9d3c1f30-8a9b-4c0d-9e1f-2a3b4c5d6e7f type: image mime_type: image/jpeg original_filename: launch.jpg '403': description: The signature is invalid or the URL expired. content: application/json: schema: $ref: '#/components/schemas/ErrorBody' example: message: Invalid signature. '404': description: The workspace of this URL no longer exists. content: application/json: schema: $ref: '#/components/schemas/ErrorBody' '409': description: This URL was already used. The body has an empty `message`. content: application/json: schema: $ref: '#/components/schemas/ErrorBody' example: message: '' '422': $ref: '#/components/responses/ValidationError' '429': description: >- Too many uploads. Limits: 60 per minute per workspace and 1200 per minute per IP address. headers: Retry-After: description: Seconds to wait before retrying. schema: type: integer content: application/json: schema: $ref: '#/components/schemas/RateLimitErrorBody' security: [] components: schemas: SignedUpload: type: object properties: upload_token: type: string format: uuid media_id: type: string format: uuid type: type: string enum: - image - video - document mime_type: type: string original_filename: type: string ErrorBody: type: object properties: message: type: string RateLimitErrorBody: type: object properties: name: type: string const: rate_limit_exceeded message: type: string examples: - Rate limit exceeded. Please retry after 30 seconds. ValidationErrorBody: type: object properties: message: type: string errors: type: object additionalProperties: type: array items: type: string responses: ValidationError: description: Validation failed. content: application/json: schema: $ref: '#/components/schemas/ValidationErrorBody' securitySchemes: bearerAuth: type: http scheme: bearer description: Workspace API key from Settings → API Keys. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.