media

Attach media to authored statuses. See Using Mastodon > Posting toots > Attachments for more information about size and format limits.

Upload media as attachment

POST https://mastodon.example/api/v1/media

Creates an attachment to be used with a new status. Returns: Attachment OAuth: User token + write:media Version history: 0.0.0 - added 2.3.0 - add focus parameter

Headers

Name	Type	Description
Authorization	string	Bearer <user token>

Request Body

Name	Type	Description
file	object	The file to be attached, using multipart form data.
description	string	A plain-text description of the media, for accessibility purposes.
focus	string	Two floating points (x,y), comma-delimited, ranging from -1.0 to 1.0

200 Attachment created successfully. Note that the Attachment will be created even if the file is not understood correctly.

file correct

{
  "id": "22348641",
  "type": "image",
  "url": "https://files.mastodon.social/media_attachments/files/022/348/641/original/cebc6d51be03e509.jpeg",
  "preview_url": "https://files.mastodon.social/media_attachments/files/022/348/641/small/cebc6d51be03e509.jpeg",
  "remote_url": null,
  "text_url": "https://mastodon.social/media/4Zj6ewxzzzDi0g8JnZQ",
  "meta": {
    "focus": {
      "x": -0.69,
      "y": 0.42
    },
    "original": {
      "width": 640,
      "height": 480,
      "size": "640x480",
      "aspect": 1.3333333333333333
    },
    "small": {
      "width": 461,
      "height": 346,
      "size": "461x346",
      "aspect": 1.3323699421965318
    }
  },
  "description": "test uploaded via api",
  "blurhash": "UFBWY:8_0Jxv4mx]t8t64.%M-:IUWGWAt6M}"
}

file not correct

{
  "id": "22348456",
  "type": "unknown",
  "url": "https://mastodon.social/files/original/missing.png",
  "preview_url": "https://mastodon.social/files/small/missing.png",
  "remote_url": null,
  "text_url": "https://mastodon.social/media/Ao2nvQoQNHROpKgEyoA",
  "meta": {
    "focus": {
      "x": -0.69,
      "y": 0.42
    }
  },
  "description": "test uploaded via api",
  "blurhash": null
}

401 Invalid or missing Authorization header

{
  "error": "The access token is invalid"
}

422 File or file type is unsupported or invalid

{
  "error": "Validation failed: File content type is invalid, File is invalid"
}

Update attachment

PUT https://mastodon.example/api/v1/media/:id

Update an Attachment, before it is attached to a status and posted. Returns: Attachment OAuth: User token + write:media Version history: 0.0.0 - added

Path Parameters

Name	Type	Description
:id	string	The id of the Attachment entity to be updated

Headers

Name	Type	Description
Authorization	string	Bearer <user token>

Request Body

Name	Type	Description
file	object	The file to be attached, using multipart form data.
description	string	A plain-text description of the media, for accessibility purposes.
focus	string	Two floating points (x,y), comma-delimited ranging from -1.0 to 1.0

200

{
  "id": "22348641",
  "type": "image",
  "url": "https://files.mastodon.social/media_attachments/files/022/348/641/original/e96382f26c72a29c.jpeg",
  "preview_url": "https://files.mastodon.social/media_attachments/files/022/348/641/small/e96382f26c72a29c.jpeg",
  "remote_url": null,
  "text_url": "https://mastodon.social/media/4Zj6ewxzzzDi0g8JnZQ",
  "meta": {
    "focus": {
      "x": -0.42,
      "y": 0.69
    },
    "original": {
      "width": 640,
      "height": 480,
      "size": "640x480",
      "aspect": 1.3333333333333333
    },
    "small": {
      "width": 461,
      "height": 346,
      "size": "461x346",
      "aspect": 1.3323699421965318
    }
  },
  "description": "test uploaded via api, but updated",
  "blurhash": "UFBWY:8_0Jxv4mx]t8t64.%M-:IUWGWAt6M}"
}

401 Invalid or missing Authorization header

{
  "error": "The access token is invalid"
}

404 Attachment does not exist, is deleted, or was not created by you

{
  "error": "Record not found"
}

422 File or file type is unsupported or invalid

{
  "error": "Validation failed: File content type is invalid, File is invalid"
}

Focal points

Server-side preview images are never cropped, to support a variety of apps and user interfaces. Therefore, the cropping must be done by those apps. To crop intelligently, focal points can be used to ensure a certain section of the image is always within the cropped viewport. See this guide on how focal points are defined. In summary, floating points range from -1.0 to 1.0, left-to-right or bottom-to-top. (0,0) is the center of the image. (0.5, 0.5) would be in the center of the upper-right quadrant. (-0.5, -0.5) would be in the center of the lower-left quadrant. For reference, thumbnails in the Mastodon frontend are most commonly 16:9.

A demonstration of various focal points and their coordinates.

A demonstration of various focal points and their coordinates.