MiniMax H3 video generation

MiniMax's H3 model, called directly against MiniMax rather than through a broker. It generates 5–15 second clips at 2K (2560×1440) at 24 fps with a native stereo audio track, and covers five input modes: text-to-video, first-frame, last-frame, first-and-last-frame, and reference-to-video with up to nine reference images plus three video and three audio clips.

Unlike most engines here there is no operation discriminator — the mode is inferred from which media fields you populate:

Mode	Populate	aspectRatio
Text-to-video	nothing but prompt	a concrete ratio (not adaptive)
Image-to-video	firstFrameImage	ignored — derived from the image
Last-frame	lastFrameImage	ignored
First and last frame	both firstFrameImage and lastFrameImage	ignored
Reference-to-video	any of referenceImages (≤9), referenceVideos (≤3), referenceAudios (≤3)	ignored

Default choice: resolution: "2K", duration: 5, aspectRatio: "16:9". Every H3 job exceeds the 100-second request timeout — always submit with wait=0.

The request shape

A single videoGen step on SubmitWorkflow. engine is the only discriminator:

{
  "$type": "videoGen",
  "input": {
    "engine": "minimax-h3",
    "prompt": "…",
    "resolution": "2K",
    "duration": 5
  }
}

Text-to-video

Text-to-video is the one mode that requires a concrete aspectRatio — MiniMax rejects adaptive when there is no image to derive geometry from. If you leave it at the default, 16:9 is substituted for you.

POST https://orchestration.civitai.com/v2/consumer/workflows?wait=0
Authorization: Bearer <your-token>
Content-Type: application/json

{
  "steps": [{
    "$type": "videoGen",
    "input": {
      "engine": "minimax-h3",
      "prompt": "A golden retriever puppy running along a sunny beach, waves splashing, cinematic slow motion",
      "aspectRatio": "16:9",
      "resolution": "2K",
      "duration": 5
    }
  }]
}

POST/v2/consumer/workflows

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

{ "steps": [ { "$type": "videoGen", "input": { "engine": "minimax-h3", "prompt": "A golden retriever puppy running along a sunny beach, waves splashing, cinematic slow motion", "aspectRatio": "16:9", "resolution": "2K", "duration": 5 } } ] }

Valid JSON

Image-to-video

Pass firstFrameImage to animate forward from a still. aspectRatio is ignored — the output geometry follows the image.

{
  "engine": "minimax-h3",
  "prompt": "Pull focus to the people in the background and add steam rising from the bowl",
  "firstFrameImage": "https://image.civitai.com/.../first-frame.jpeg",
  "resolution": "2K",
  "duration": 5
}

POST/v2/consumer/workflows

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

{ "steps": [ { "$type": "videoGen", "input": { "engine": "minimax-h3", "prompt": "Pull focus to the people in the background and add steam rising from the bowl", "firstFrameImage": "https://image.civitai.com/xG1nkqKTMzGDvpLrqFT7WA/c7281429-7dc8-4256-9907-2e2c55137f40/original=true,quality=90,optimized=true/42750475.jpeg", "resolution": "2K", "duration": 5 } } ] }

Valid JSON

Last frame

Pass lastFrameImage instead to generate the run-up that ends on the supplied still.

{
  "engine": "minimax-h3",
  "prompt": "The camera slowly pushes in until it settles on this composition",
  "lastFrameImage": "https://image.civitai.com/.../final-frame.jpeg",
  "resolution": "2K",
  "duration": 5
}

POST/v2/consumer/workflows

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

{ "steps": [ { "$type": "videoGen", "input": { "engine": "minimax-h3", "prompt": "The camera slowly pushes in until it settles on this composition", "lastFrameImage": "https://image.civitai.com/xG1nkqKTMzGDvpLrqFT7WA/c7281429-7dc8-4256-9907-2e2c55137f40/original=true,quality=90,optimized=true/42750475.jpeg", "resolution": "2K", "duration": 5 } } ] }

Valid JSON

First and last frame

Supply both and H3 interpolates between them.

{
  "engine": "minimax-h3",
  "prompt": "A smooth cinematic transition between the two compositions",
  "firstFrameImage": "https://image.civitai.com/.../start.jpeg",
  "lastFrameImage": "https://image.civitai.com/.../end.jpeg",
  "resolution": "2K",
  "duration": 5
}

POST/v2/consumer/workflows

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

{ "steps": [ { "$type": "videoGen", "input": { "engine": "minimax-h3", "prompt": "A smooth cinematic transition between the two compositions", "firstFrameImage": "https://image.civitai.com/xG1nkqKTMzGDvpLrqFT7WA/c7281429-7dc8-4256-9907-2e2c55137f40/original=true,quality=90,optimized=true/42750475.jpeg", "lastFrameImage": "https://image.civitai.com/xG1nkqKTMzGDvpLrqFT7WA/dd4b4ad5-040f-4f0e-baa3-6e1ff00add65/original=true,quality=90,optimized=true/26781018.jpeg", "resolution": "2K", "duration": 5 } } ] }

Valid JSON

Reference-to-video

Guide generation with up to nine reference images, three reference video clips, and three reference audio clips. Reference media cannot be combined with firstFrameImage/lastFrameImage — MiniMax treats those as different task types, and mixing them is rejected with a 400.

{
  "engine": "minimax-h3",
  "prompt": "The character from the references walks through a rain-soaked night market",
  "referenceImages": [
    "https://image.civitai.com/.../subject-a.jpeg",
    "https://image.civitai.com/.../subject-b.jpeg"
  ],
  "resolution": "2K",
  "duration": 5
}

Reference audio is how you drive a spoken performance — describe the line in the prompt and the voice timbre follows the supplied clip.

POST/v2/consumer/workflows

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

{ "steps": [ { "$type": "videoGen", "input": { "engine": "minimax-h3", "prompt": "The character from the references walks through a rain-soaked night market", "referenceImages": [ "https://image.civitai.com/xG1nkqKTMzGDvpLrqFT7WA/c7281429-7dc8-4256-9907-2e2c55137f40/original=true,quality=90,optimized=true/42750475.jpeg", "https://image.civitai.com/xG1nkqKTMzGDvpLrqFT7WA/dd4b4ad5-040f-4f0e-baa3-6e1ff00add65/original=true,quality=90,optimized=true/26781018.jpeg" ], "resolution": "2K", "duration": 5 } } ] }

Valid JSON

Reference media must be publicly reachable

MiniMax fetches referenceVideos and referenceAudios server-side, from its own infrastructure. Signed URLs that expire, private buckets, and internal hostnames all fail with an opaque 400. Host the media somewhere publicly fetchable for the lifetime of the job. Images passed via firstFrameImage, lastFrameImage, and referenceImages go through the Civitai image pipeline first and don't have this restriction.

Parameters

The schema in the API reference is authoritative.

Field	Default	Notes
engine	— ✅	"minimax-h3"
prompt	— ✅	Up to 7000 characters.
resolution	"2K"	"2K" is the only value H3 accepts today; MiniMax has a cheaper 768P tier in flight. H3's 2K is natively generated rather than upscaled.
duration	5	Integer seconds, 5–15.
aspectRatio	"adaptive"	"adaptive", "21:9", "16:9", "4:3", "1:1", "3:4", "9:16". Only read for text-to-video, where adaptive is not allowed.
firstFrameImage	—	Single image used as the opening frame.
lastFrameImage	—	Single image used as the closing frame.
referenceImages[]	[]	Up to 9. First 5 free, then billed. Cannot be combined with first/last frame.
referenceVideos[]	[]	Up to 3, 2–15 s each and ≤15 s in total, ≤50 MB, MP4/MOV.
referenceAudios[]	[]	Up to 3, 2–15 s each, ≤15 MB, WAV/MP3. Must accompany a reference image or video.
watermark	false	Adds MiniMax's AIGC watermark to the output.

Image limits: 256–5760 px per side, aspect ratio between 0.4 and 2.5, ≤30 MB, JPG/PNG/WEBP/HEIC/HEIF.

Cost

Billed per second in Buzz on the workflow's transactions. Use whatif=true for an exact preview; see Payments (Buzz) for currency selection.

total = 170 × (duration + referenceVideoSeconds) + 52 × max(0, referenceImages − 5)

duration	5 s	10 s	15 s
2K, no reference media	850	1 700	2 550

Three rules govern reference input:

Reference input	Billing
Audio	Free
Image	First 5 free, then 52 Buzz each
Video	Billed at the output rate — 170 Buzz per second of uploaded clip

Reference video is charged on the length of the clip you upload, not the output. A 10-second generation over a 5-second reference clip bills 15 seconds, so whatif=true measures your clips before quoting. Some worked examples:

Scenario	Total
10 s, no reference	1 700
10 s + 3 reference images	1 700
10 s + 8 reference images	1 700 + 3 × 52 = 1 856
10 s + a 5 s reference video	15 × 170 = 2 550

Failed generations and clips rejected by MiniMax's content review are not charged.

Reading the result

Same as any videoGen step — a single video blob:

{
  "steps": [{
    "output": {
      "video": {
        "id": "…",
        "url": "https://orchestration.civitai.com/v2/consumer/blobs/…"
      }
    }
  }]
}

The blob URL is signed and expires — refetch the workflow with GetWorkflow for a fresh one rather than storing it.

The output is H.264 at 2560×1440 in an MP4 container, with an AAC audio track generated alongside the video. A 5-second clip is roughly 6 MB.

Runtime

A 5-second 2K clip takes around three minutes end to end, and 15-second clips considerably longer — far past the 100-second inline request budget. Submit with wait=0 and collect the result via a webhook or by polling — see Results and webhooks.

Troubleshooting

Symptom	Cause	Fix
400 mentioning ratio	adaptive on a text-to-video request	Pass a concrete aspectRatio, or supply a firstFrameImage.
400 mentioning resolution	Anything other than 2K	H3 supports only 2K.
400 on a reference-media request	URL not publicly fetchable, or a clip outside the size/duration limits	Check the limits above and that the URL resolves from the public internet.
400 combining reference media with a frame image	Different MiniMax task types	Use one or the other.
Content-policy rejection	MiniMax's own input review	Rephrase the prompt or swap the source media. Not billed.
Job retries across workers	Provider rate limit	Expected under load — H3 capacity is intentionally throttled.

Related

• SubmitWorkflow · GetWorkflow
• Other video engines: WAN, Veo 3, Kling, Happy-Horse, FLUX-3
• Schema: MiniMaxH3VideoGenInput in the API reference