AI: Texts & Animated Subtitles

The AI features of the post form, from the API: write a post’s texts from what is said in a video, and burn animated subtitles into it.

Billed in credits: 1 AI minute per started minute of video, from the plan’s monthly AI minutes first, then purchased credits. A video is transcribed and billed once: generating its texts and then its subtitles pays once. Rendering the subtitles is included. Videos up to 30 minutes. In a team, the team owner’s plan pays. GET /x-credits returns what is left in ai.

mediaUrl is a video you uploaded (presign or a previous post), or any public https video URL.

Texts from a video

POST /api/v1/ai/post-text — scope posts:write.

Field	Required	Description
`mediaUrl`	Yes	The video.
`platforms`	Yes	Platforms to write for, e.g. `["tiktok", "instagram", "youtube"]`.
`accountIds`	No	Accounts the post will go to: their best-performing hashtags are reused.
`draft`	No	Your own draft or instructions to take into account (5,000 characters max).


curl -X POST https://api.multi-upload-tool.com/api/v1/ai/post-text \
  -H "x-api-key: YOUR_API_TOKEN" -H "Content-Type: application/json" \
  -d '{ "mediaUrl": "https://example.com/video.mp4", "platforms": ["tiktok", "youtube"] }'


{
  "success": true,
  "data": {
    "title": "3 tips for short videos",
    "description": "Three simple tips to get more views on your short videos. #shortvideo #tips",
    "hashtags": ["shortvideo", "tips"],
    "captions": [
      { "platform": "tiktok", "text": "3 tips nobody tells you 👇 #shortvideo #tips" },
      { "platform": "youtube", "text": "Three simple tips to get more views on your short videos." }
    ],
    "language": "en",
    "minutesCharged": 1
  }
}

Texts are written in the video’s language. Nothing is published: pass them to POST /upload. minutesCharged is 0 when the video was already transcribed.

Animated subtitles

POST /api/v1/ai/captions — scope posts:write. Transcribes the video, lets the AI pick the keywords (and emojis), then renders the subtitles into a new video in the background, usually in under a minute.

Field	Default	Description
`mediaUrl`	—	The video (required).
`theme`	`hormozi`	`hormozi` (bold uppercase, spoken word in yellow), `beast`, `box` (text on a dark box), `single` (one word at a time), `minimal`, `podcast`.
`position`	theme’s	Vertical centre of the line: `0` top, `1` bottom.
`scale`	`1`	Text size, `0.5` to `2`.
`wordsPerLine`	theme’s	`1` to `8`. More words per line = lines change less often, a calmer pace.
`highlights`	`true`	Keywords in colour.
`emojis`	`false`	One emoji above each line when the AI picked one.
`emojiStyle`	`noto`	`noto` (flat Google emojis) or `fluent` (3D).
`colors`	theme’s	`{ "text", "active", "highlight" }` as `#RRGGBB`: text, spoken word, keywords.
`enter`	theme’s	How a line comes in: `pop`, `fade` or `none`.
`exit`	`none`	How a line goes out: `fade` or `none`.


curl -X POST https://api.multi-upload-tool.com/api/v1/ai/captions \
  -H "x-api-key: YOUR_API_TOKEN" -H "Content-Type: application/json" \
  -d '{ "mediaUrl": "https://example.com/video.mp4", "theme": "minimal", "enter": "fade", "exit": "fade" }'


{ "success": true, "data": { "jobId": "1234", "minutesCharged": 1 } }

Get the captioned video

GET /api/v1/ai/captions/{jobId} — scope posts:read. Poll every few seconds until state is completed (with url) or failed (with error).


{ "success": true, "data": { "state": "completed", "url": "https://api.multi-upload-tool.com/api/public/image-proxy/public-api/42/1730000000000-captioned.mp4" } }

Publish url with POST /upload instead of the original video.

Errors

Status	When
`400`	Unknown `theme` (checked before anything is billed).
`402`	Not enough AI minutes or credits for this video.
`403`	The URL points to another user’s upload.
`409`	The same video is already being transcribed by another call: retry in a minute, it will not be billed twice.
`422`	The file is not a readable video, is longer than 30 minutes, or has no speech (not billed).
`404`	Unknown `jobId`, or a render started by another user.