> ## Documentation Index > Fetch the complete documentation index at: https://docs.oxen.ai/llms.txt > Use this file to discover all available pages before exploring further. # Kling O3 4K - Reference to Video > 4K reference-driven video Run this model interactively, tune parameters, and compare outputs. **Model ID:** `kling-video-o3-4k-reference-to-video` Part of the Kling 3.0/o3 family on fal.ai, this 4K reference-to-video model generates native 4K (3840x2160) video from reference images and text prompts with no upscaling step. It excels at preserving identity, layout, and stylistic detail while adding cinematic motion, camera movement, and scene progression. Supports element and style references (combined limit of 7), optional start and end frame anchoring, multi-shot generation up to 15 seconds, and optional native synchronized audio in English and Chinese. Optimized for advertising, branded content, and production-grade scene work where 4K detail is required. ## Example request Use the [Workbench](https://www.oxen.ai/ai/workbench?model=kling-video-o3-4k-reference-to-video) as a request builder: configure parameters for this model in the UI, then open the **API** tab to copy the exact cURL or Python call. This blocks until the video is ready (typically 5-15 minutes). Prefer **Async** or **Async with SSE** for anything beyond quick experimentation. See the [video generation reference](/inference-api/reference/video_generation) for more details. ```bash cURL theme={null} curl -X POST https://hub.oxen.ai/api/ai/videos/generate \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video" }' ``` ```python Python theme={null} import os import requests response = requests.post( "https://hub.oxen.ai/api/ai/videos/generate", headers={ "Content-Type": "application/json", "Authorization": f"Bearer {os.environ['OXEN_API_KEY']}", }, json={ "model": "kling-video-o3-4k-reference-to-video" }, ) response.raise_for_status() print(response.json()) ``` ```bash cURL theme={null} curl -X POST https://hub.oxen.ai/api/ai/videos/generate \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ] }' ``` ```python Python theme={null} import os import requests response = requests.post( "https://hub.oxen.ai/api/ai/videos/generate", headers={ "Content-Type": "application/json", "Authorization": f"Bearer {os.environ['OXEN_API_KEY']}", }, json={ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ] }, ) response.raise_for_status() print(response.json()) ``` ```bash cURL theme={null} curl -X POST https://hub.oxen.ai/api/ai/videos/generate \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ], "aspect_ratio": "16:9", "generate_audio": false }' ``` ```python Python theme={null} import os import requests response = requests.post( "https://hub.oxen.ai/api/ai/videos/generate", headers={ "Content-Type": "application/json", "Authorization": f"Bearer {os.environ['OXEN_API_KEY']}", }, json={ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ], "aspect_ratio": "16:9", "generate_audio": false }, ) response.raise_for_status() print(response.json()) ``` See the [async queue reference](/inference-api/reference/async_queue) for more details. ```bash cURL theme={null} # Enqueue, capture the generation id. GEN_ID=$(curl -s -X POST https://hub.oxen.ai/api/ai/queue \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video" }' | jq -r '.generations[0].generation_id') # Poll until the generation reaches a terminal status. while true; do STATUS=$(curl -s -H "Authorization: Bearer $OXEN_API_KEY" \ "https://hub.oxen.ai/api/ai/queue/$GEN_ID" | jq -r '.status') echo "Status: $STATUS" case $STATUS in succeeded|failed|cancelled) break;; esac sleep 5 done # Print the result. curl -s -H "Authorization: Bearer $OXEN_API_KEY" \ "https://hub.oxen.ai/api/ai/queue/$GEN_ID" | jq . ``` ```python Python theme={null} import os import time import requests HEADERS = { "Content-Type": "application/json", "Authorization": f"Bearer {os.environ['OXEN_API_KEY']}", } enqueue = requests.post( "https://hub.oxen.ai/api/ai/queue", headers=HEADERS, json={ "model": "kling-video-o3-4k-reference-to-video" }, ) enqueue.raise_for_status() generation_id = enqueue.json()["generations"][0]["generation_id"] while True: data = requests.get( f"https://hub.oxen.ai/api/ai/queue/{generation_id}", headers=HEADERS, ).json() if data["status"] in {"succeeded", "failed", "cancelled"}: break time.sleep(5) if data["status"] == "succeeded": print(f"Result: {data['result_url']}") else: print(f"Generation {data['status']}: {data.get('error_message')}") ``` ```bash cURL theme={null} # Enqueue, capture the generation id. GEN_ID=$(curl -s -X POST https://hub.oxen.ai/api/ai/queue \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ] }' | jq -r '.generations[0].generation_id') # Poll until the generation reaches a terminal status. while true; do STATUS=$(curl -s -H "Authorization: Bearer $OXEN_API_KEY" \ "https://hub.oxen.ai/api/ai/queue/$GEN_ID" | jq -r '.status') echo "Status: $STATUS" case $STATUS in succeeded|failed|cancelled) break;; esac sleep 5 done # Print the result. curl -s -H "Authorization: Bearer $OXEN_API_KEY" \ "https://hub.oxen.ai/api/ai/queue/$GEN_ID" | jq . ``` ```python Python theme={null} import os import time import requests HEADERS = { "Content-Type": "application/json", "Authorization": f"Bearer {os.environ['OXEN_API_KEY']}", } enqueue = requests.post( "https://hub.oxen.ai/api/ai/queue", headers=HEADERS, json={ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ] }, ) enqueue.raise_for_status() generation_id = enqueue.json()["generations"][0]["generation_id"] while True: data = requests.get( f"https://hub.oxen.ai/api/ai/queue/{generation_id}", headers=HEADERS, ).json() if data["status"] in {"succeeded", "failed", "cancelled"}: break time.sleep(5) if data["status"] == "succeeded": print(f"Result: {data['result_url']}") else: print(f"Generation {data['status']}: {data.get('error_message')}") ``` ```bash cURL theme={null} # Enqueue, capture the generation id. GEN_ID=$(curl -s -X POST https://hub.oxen.ai/api/ai/queue \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ], "aspect_ratio": "16:9", "generate_audio": false }' | jq -r '.generations[0].generation_id') # Poll until the generation reaches a terminal status. while true; do STATUS=$(curl -s -H "Authorization: Bearer $OXEN_API_KEY" \ "https://hub.oxen.ai/api/ai/queue/$GEN_ID" | jq -r '.status') echo "Status: $STATUS" case $STATUS in succeeded|failed|cancelled) break;; esac sleep 5 done # Print the result. curl -s -H "Authorization: Bearer $OXEN_API_KEY" \ "https://hub.oxen.ai/api/ai/queue/$GEN_ID" | jq . ``` ```python Python theme={null} import os import time import requests HEADERS = { "Content-Type": "application/json", "Authorization": f"Bearer {os.environ['OXEN_API_KEY']}", } enqueue = requests.post( "https://hub.oxen.ai/api/ai/queue", headers=HEADERS, json={ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ], "aspect_ratio": "16:9", "generate_audio": false }, ) enqueue.raise_for_status() generation_id = enqueue.json()["generations"][0]["generation_id"] while True: data = requests.get( f"https://hub.oxen.ai/api/ai/queue/{generation_id}", headers=HEADERS, ).json() if data["status"] in {"succeeded", "failed", "cancelled"}: break time.sleep(5) if data["status"] == "succeeded": print(f"Result: {data['result_url']}") else: print(f"Generation {data['status']}: {data.get('error_message')}") ``` See the [async queue reference](/inference-api/reference/async_queue) for more details. ```bash cURL theme={null} # Enqueue, capture the generation id. GEN_ID=$(curl -s -X POST https://hub.oxen.ai/api/ai/queue \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video" }' | jq -r '.generations[0].generation_id') # Stream the SSE channel, grab the data line that follows a # media_generation_completed event for our id, and pretty-print it. curl -sN -H "Authorization: Bearer $OXEN_API_KEY" https://hub.oxen.ai/api/events \ | awk -v id="$GEN_ID" ' /^event: media_generation_completed$/ { expect=1; next } /^data: / && expect { payload = substr($0, 7) if (index(payload, "\"generation_id\":\"" id "\"")) { print payload; exit } expect = 0 } ' | jq . ``` ```python Python theme={null} import json import os import requests API_KEY = os.environ["OXEN_API_KEY"] AUTH = {"Authorization": f"Bearer {API_KEY}"} enqueue = requests.post( "https://hub.oxen.ai/api/ai/queue", headers={**AUTH, "Content-Type": "application/json"}, json={ "model": "kling-video-o3-4k-reference-to-video" }, ) enqueue.raise_for_status() generation_id = enqueue.json()["generations"][0]["generation_id"] with requests.get( "https://hub.oxen.ai/api/events", headers=AUTH, stream=True, ) as stream: event_name = None for line in stream.iter_lines(decode_unicode=True): if line.startswith("event: "): event_name = line.removeprefix("event: ") elif line.startswith("data: ") and event_name == "media_generation_completed": payload = json.loads(line.removeprefix("data: ")) if payload.get("generation_id") == generation_id: print(payload) break ``` ```bash cURL theme={null} # Enqueue, capture the generation id. GEN_ID=$(curl -s -X POST https://hub.oxen.ai/api/ai/queue \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ] }' | jq -r '.generations[0].generation_id') # Stream the SSE channel, grab the data line that follows a # media_generation_completed event for our id, and pretty-print it. curl -sN -H "Authorization: Bearer $OXEN_API_KEY" https://hub.oxen.ai/api/events \ | awk -v id="$GEN_ID" ' /^event: media_generation_completed$/ { expect=1; next } /^data: / && expect { payload = substr($0, 7) if (index(payload, "\"generation_id\":\"" id "\"")) { print payload; exit } expect = 0 } ' | jq . ``` ```python Python theme={null} import json import os import requests API_KEY = os.environ["OXEN_API_KEY"] AUTH = {"Authorization": f"Bearer {API_KEY}"} enqueue = requests.post( "https://hub.oxen.ai/api/ai/queue", headers={**AUTH, "Content-Type": "application/json"}, json={ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ] }, ) enqueue.raise_for_status() generation_id = enqueue.json()["generations"][0]["generation_id"] with requests.get( "https://hub.oxen.ai/api/events", headers=AUTH, stream=True, ) as stream: event_name = None for line in stream.iter_lines(decode_unicode=True): if line.startswith("event: "): event_name = line.removeprefix("event: ") elif line.startswith("data: ") and event_name == "media_generation_completed": payload = json.loads(line.removeprefix("data: ")) if payload.get("generation_id") == generation_id: print(payload) break ``` ```bash cURL theme={null} # Enqueue, capture the generation id. GEN_ID=$(curl -s -X POST https://hub.oxen.ai/api/ai/queue \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $OXEN_API_KEY" \ -d '{ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ], "aspect_ratio": "16:9", "generate_audio": false }' | jq -r '.generations[0].generation_id') # Stream the SSE channel, grab the data line that follows a # media_generation_completed event for our id, and pretty-print it. curl -sN -H "Authorization: Bearer $OXEN_API_KEY" https://hub.oxen.ai/api/events \ | awk -v id="$GEN_ID" ' /^event: media_generation_completed$/ { expect=1; next } /^data: / && expect { payload = substr($0, 7) if (index(payload, "\"generation_id\":\"" id "\"")) { print payload; exit } expect = 0 } ' | jq . ``` ```python Python theme={null} import json import os import requests API_KEY = os.environ["OXEN_API_KEY"] AUTH = {"Authorization": f"Bearer {API_KEY}"} enqueue = requests.post( "https://hub.oxen.ai/api/ai/queue", headers={**AUTH, "Content-Type": "application/json"}, json={ "model": "kling-video-o3-4k-reference-to-video", "start_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "tail_image_url": "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png", "input_image": [ "https://hub.oxen.ai/api/repos/elau/assets/file/main/bloxy/bloxy_cropped_512x512.png" ], "aspect_ratio": "16:9", "generate_audio": false }, ) enqueue.raise_for_status() generation_id = enqueue.json()["generations"][0]["generation_id"] with requests.get( "https://hub.oxen.ai/api/events", headers=AUTH, stream=True, ) as stream: event_name = None for line in stream.iter_lines(decode_unicode=True): if line.startswith("event: "): event_name = line.removeprefix("event: ") elif line.startswith("data: ") and event_name == "media_generation_completed": payload = json.loads(line.removeprefix("data: ")) if payload.get("generation_id") == generation_id: print(payload) break ``` ## Fetch model details The [models endpoint](/inference-api/reference/models/overview) returns the full model object, including its `json_request_schema`. ```bash theme={null} curl -H "Authorization: Bearer $OXEN_API_KEY" https://hub.oxen.ai/api/ai/models/kling-video-o3-4k-reference-to-video ``` ## Request parameters ### Optional parameters | Field | Type | Default | Description | | ----------------- | --------------- | -------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `start_image_url` | `string` | — | The first frame of the video. The model will try to extend the contents of this frame. Format: uri. | | `tail_image_url` | `string` | — | The last frame of the video. Requires start frame to be configured. The model will try to fill in between the frames. Format: uri. | | `input_image` | `array` | — | Reference images for style/appearance. Use @Image1, @Image2, etc. in the prompt to refer to them. Maximum 4 total (elements + reference images) when using video. | | `elements` | `array` | — | Optional element references. Use @Element1, @Element2, etc. in the prompt to refer to them. | | `negative_prompt` | `string` | — | Text describing what to avoid in the generated video. | | `aspect_ratio` | `string` | `"16:9"` | Video aspect ratio One of: 9:16, 1:1, 16:9. | | `generate_audio` | `boolean` | `false` | Whether to generate native audio for the video. Supports Chinese and English voice output. |