Video GenerationHappyHorse
HappyHorse Text-to-Video
POST /api/v1/services/aigc/video-generation/video-synthesis — generate video from a text prompt
The HappyHorse text-to-video model turns a text prompt into physically plausible, motion-coherent video.
Models
| Model | Notes |
|---|---|
happyhorse-1.1-t2v | Generation 1.1 |
happyhorse-1.0-t2v | Generation 1.0 |
happyhorse-1.0-t2v-20260618 | Generation 1.0, 20260618 snapshot |
Create a job
POST
/api/v1/services/aigc/video-generation/video-synthesiscurl https://api.modelsite.ai/api/v1/services/aigc/video-generation/video-synthesis \
-H "Authorization: Bearer $MODELSITE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "happyhorse-1.1-t2v",
"input": {
"prompt": "A golden retriever running on a beach at sunset, waves crashing, cinematic lighting"
},
"parameters": {
"resolution": "720P",
"ratio": "16:9",
"duration": 5
}
}'Request body
| Field | Type | Notes |
|---|---|---|
model | string (required) | See the table above |
input.prompt | string (required) | The prompt. CJK characters count as 2, everything else as 1, budget 5000 — exceeding it is an error |
parameters | object (optional) | Generation knobs, below |
parameters
| Parameter | Type | Notes |
|---|---|---|
resolution | string | Tier: 480P / 720P / 1080P (default). The sellable tiers follow this model's price configuration; an unpriced tier is refused with InvalidParameter |
ratio | string | Aspect ratio: 16:9 (default) / 9:16 / 1:1 / 4:3 / 3:4 / 4:5 / 5:4 / 9:21 / 21:9 |
duration | integer | Seconds, integer in [3, 15], default 5 |
watermark | boolean | Adds the "Happy Horse" corner stamp. Defaults to true — pass false explicitly when you don't want it |
seed | integer | [0, 2147483647]; the same seed does not guarantee identical output |
negative_prompt | string | Negative prompt |
Other vendor-native parameters can be written into parameters and pass through verbatim — no wrapping.
Polling and result
GET
/api/v1/tasks/{task_id}curl "https://api.modelsite.ai/api/v1/tasks/$TASK_ID" \
-H "Authorization: Bearer $MODELSITE_API_KEY"Response fields
| Field | Meaning |
|---|---|
output.task_id | Job ID (same value returned at creation) |
output.task_status | PENDING queued / RUNNING processing / SUCCEEDED done / FAILED failed |
output.video_url | The generated video URL — only on SUCCEEDED; download promptly |
output.code / output.message | Present only on failure, with the reason |
usage | Usage stats (duration, resolution tier, …); counted only on success |
request_id | Unique request ID — include it when reporting issues |
Status flow: PENDING → RUNNING → SUCCEEDED / FAILED.
Billing
Billed by actual generated seconds; the resolution tier affects the rate; failed jobs are not billed. Rates on the Models page.
Error handling
Creation-time parameter errors return 4xx with {"code": "...", "message": "..."} (e.g. InvalidParameter). Mid-job failures surface through the poll response's output.code / output.message. General error codes: Errors.