HappyHorse 1.1 Serverless API

Generate cinematic video with synchronized native audio and multilingual lip-sync from text, an image, or reference images.

~152.79s
POST /v2/happyhorse-1.1 · submit + poll
 1# pip install "segmind>=1.1.0"
 2# export SEGMIND_API_KEY="YOUR_API_KEY"
 3from segmind import SegmindClient, InferenceFailed, InferenceTimeout
 4
 5# Async (v2) — recommended for long-running / video models.
 6# run() blocks up to 600s; submit_async + job.wait(timeout=...) sets a longer
 7# deadline and keeps the request_id so you can re-poll later.
 8client = SegmindClient()                      # reads SEGMIND_API_KEY
 9payload = {
10    "prompt": "A majestic white horse galloping through golden wheat fields at sunset, cinematic slow motion, warm golden hour lighting, dust particles catching sunlight, shallow depth of field, professional nature documentary style",
11    "negative_prompt": "blurry, low quality, distorted, watermark, text",
12    "resolution": "720P",
13    "duration": 5,
14    "aspect_ratio": "16:9",
15    "prompt_extend": True,
16    "watermark": False,
17}
18job = client.submit_async("happyhorse-1.1", **payload)
19print(job.request_id)                         # available immediately
20try:
21    result = job.wait(timeout=900, interval=2.0)
22    print(result["status"])                  # COMPLETED
23    print(result.get("output"))              # model output (e.g. video URL)
24except InferenceTimeout as e:
25    print("still running:", e.request_id)    # re-poll later with this id
26except InferenceFailed as e:
27    print("failed:", e.detail)
28
29# Fast models (<=600s) can use the one-liner instead:
30# result = segmind.run("happyhorse-1.1", **payload)

API Endpoint

POSThttps://api.segmind.com/v1/happyhorse-1.1

Parameters

promptrequired
string

Describes the scene, subjects, motion, camera, and audio cues. Use cinematic detail (lighting, lens, dialogue) for richer video and synced native audio.

Default: "A majestic white horse galloping through golden wheat fields at sunset, cinematic slow motion, warm golden hour lighting, dust particles catching sunlight, shallow depth of field, professional nature documentary style"
aspect_ratiooptional
string

Frame shape for text-to-video (ignored when an image is supplied). Use 16:9 for landscape, 9:16 for vertical, 1:1 for social.

Default: "16:9"
Allowed values :
"16:9""9:16""1:1""4:3""3:4"
durationoptional
integer

Video length in seconds, from 3 to 15. Use 3-5s for quick social clips; 8-15s for fuller scenes and narratives.

Default: 5
imageoptional
string (uri)

Optional first frame that triggers image-to-video mode. Provide a URL or base64 image to animate it; leave empty for text-to-video.

Default: null
negative_promptoptional
string

Lists elements to suppress in the output. Use it to avoid blur, artifacts, watermarks, or text; tune per scene as needed.

Default: "blurry, low quality, distorted, watermark, text"
prompt_extendoptional
boolean

LLM-rewrites short prompts into richer cinematic instructions. Keep on for brief prompts; turn off when you need exact prompt control.

Default: true
reference_imagesoptional
string[]

Up to 9 reference image URLs or uploads that anchor characters, scenes, style, or products. Use for reference-to-video and multi-scene consistency.

resolutionoptional
string

Output resolution. Pick 720P for fast drafts and previews; choose 1080P for final, delivery-ready cinematic video.

Default: "720P"
Allowed values :
"720P""1080P"
seedoptional
integer

Reproducibility seed (0-2147483647). Fix a seed to reproduce the same output; leave empty for fresh random variations.

Default: null
watermarkoptional
boolean

Adds an AI-generated watermark to the output. Disable for clean, production-ready video; enable to label generated content.

Default: false

Response Type

Returns: Video

Asynchronous requests (v2)

Use Async for video, long-running (>~60s), or high-concurrency workloads; Sync is simplest for fast image & LLM calls. Async submits a request and you poll it to completion.

  1. 1
    POST /v2/happyhorse-1.1

    Submitreturns request_id, status_url, response_url

  2. 2
    GET /v2/requests/{id}/status

    Polluntil COMPLETED or FAILED

  3. 3
    GET /v2/requests/{id}

    Resultfinal response body

Status states

QUEUEDAccepted, waiting for a worker
PROCESSINGRunning on a worker
COMPLETEDDone — result body is ready
FAILEDErrored (incl. content/RAI blocks)
  • A FAILED request is served as HTTP 422 — the body still carries the error detail.
  • An unknown or expired request_id returns HTTP 404.
  • Results are retained for 1 hour, then expire.
  • Content / RAI blocks surface as FAILED, not a separate state.
  • Track completion by polling the status endpoint.

Common Error Codes

The API returns standard HTTP status codes. Detailed error messages are provided in the response body.

400

Bad Request

Invalid parameters or request format

401

Unauthorized

Missing or invalid API key

403

Forbidden

Insufficient permissions

404

Not Found

Model or endpoint not found

406

Insufficient Credits

Not enough credits to process request

429

Rate Limited

Too many requests

500

Server Error

Internal server error

502

Bad Gateway

Service temporarily unavailable

504

Timeout

Request timed out