HappyHorse 1.1 API

Introduction

HappyHorse 1.1 Reference to video builds one shot from one to nine reference images, sent in reference_image_urls in the order the prompt refers to them. It returns 3 to 15 whole seconds at 720p or 1080p in any of nine aspect ratios, with a generated soundtrack. References are images only; no video or audio reference is accepted.

Choose a HappyHorse 1.1 mode by starting material

Key features

Nine ordered slots

With up to nine images, one request can pin a character, costume pieces, a vehicle, a location and props. The rider-jacket-bike-station example uses three stills to keep the rider, the open jacket, the motorcycle and the filling station the same from take to take, in 3:4 at 720p, so the prompt only has to name the action and the light.

Face, prop and location in one take

The three-plate-corridor example gives each image a different job: the woman, the cherry-red guitar she carries and the neon motel corridor. The prompt says which image is which, then asks for one backward-tracking take in which face, prop and location all have to survive together.

Nine frame shapes on this endpoint

aspect_ratio offers nine values with 16:9 as the default, including 1:1, 4:5 and 5:4. The product-in-place example is square at 1080p: a candle jar from one image placed on a marble shelf from another, lit to match the shelf's window light.

Request parameters

Pricing

Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.

For an exact number before you run, send the same body to POST /jobs/quote.

Use cases

A product in its setting

Send the product and the location as separate images and describe how they interact. In product-in-place the camera pushes in slowly as the wick lights and a thread of smoke rises, and the flame's glow adds a second, warm light onto the marble and the linen.

A consistent cast and wardrobe across a series

Reuse the same reference set for every shot so the performer, the costume and the vehicle stay the same from take to take, and change only the action line of the prompt. Keep the images in the same order each time so the positional references still point at the right picture.

Prompt guide & pro tips

Refer to images by position

Say what each image contributes before describing the shot. The published examples use two positional styles: "Use the woman from the first image exactly as she appears" and "Place the candle jar from [Image 1] into the empty centre of the marble shelf in [Image 2]". Upload the files in the same order the prompt names them.

One job per image

Nine slots is a ceiling, not a target. Several views of the same subject get averaged rather than reconciled, so give each image a distinct job such as identity, garment, prop or location. Each image needs a shortest side of at least 400 px and a file size of up to 20 MB.

Spend the prompt on action and light

Once identity is settled by the references, the prompt says what the subject does, not what they look like: "he swings a leg over the tank and settles, the overhead light pressing down from directly above, moths in the beam". Keep lighting instructions consistent with the location image, as product-in-place does by matching the shelf's light direction and colour temperature.

API quick start

Call the HappyHorse 1.1 API in three steps

1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
2. Send the request. POST /jobs/createTask with model alibaba/happyhorse-1.1/reference-to-video and an input object that follows the parameter table. The response returns a task ID straight away.
3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.

# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "alibaba/happyhorse-1.1/reference-to-video",
  "input": {
    "prompt": "A slow aerial shot drifting over a misty pine forest at sunrise",
    "reference_image_urls": [
      "https://media.popnow.ai/influencer/examples/ava.webp"
    ],
    "aspect_ratio": "16:9",
    "resolution": "720p",
    "duration_seconds": 5
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

HappyHorse 1.1 API questions

Other video APIs

• MiniMax H3 APIExpressive clips with audio, up to 2KFrom 28 credits for a 5-second clip
• Wan 3.0 APIUp to 30-second clips with synced audioFrom 34 credits for a 5-second clip
• Wan 3.0 Prime APIQuicker Wan 3.0 renders, up to 30 seconds with audioFrom 46 credits for a 5-second clip
• Seedance 2.5 APIByteDance's newest: 30-second clips with native audioFrom 56 credits for a 5-second clip
• Kling 3.0 API4K clips, multi-shot cuts and motion controlFrom 51 credits for a 5-second clip
• Vidu Q4 Preview APIUp to 4K clips with sound and spoken dialogueFrom 34 credits for a 5-second clip

More about HappyHorse 1.1

Try it

HappyHorse 1.1 AI Video Generator onlineCreate videos with HappyHorse 1.1 in PopNow

Docs

HappyHorse 1.1 model ID and input schema in the API docsPopNow API quickstart: your first request in five minutesImage to video guide for the PopNow APIWebhooks: get HappyHorse 1.1 results without polling