> ## Documentation Index
> Fetch the complete documentation index at: https://docs.comfy.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Use Higgsfield Kling 3.4k with Comfy Router

> Call higgsfield/higgsfield-kling-3-4k through Comfy Router: endpoint, request shape and the response Router returns.

API Reference for `higgsfield/higgsfield-kling-3-4k`, served by Comfy Router from Higgsfield.

**Input:** Text · **Output:** Video + Audio

## Quick start

Create a key in [your Comfy workspace](https://platform.comfy.org/profile/api-keys?onboarding=router) and export it as `COMFY_API_KEY`. The Python and TypeScript snippets use the Comfy SDKs (`pip install comfy-sdk` and `npm install @comfyorg/sdk`); the cURL snippet is the same call over raw HTTP.

**Model ID:** `higgsfield/higgsfield-kling-3-4k`

**Endpoint:** `POST https://api.comfy.org/v2/models/higgsfield/higgsfield-kling-3-4k`

**Wait for the result**

```python Python theme={null}
from comfy_sdk import Comfy

# Reads COMFY_API_KEY from the environment.
# The SDK automatically creates an idempotency key and reuses it for automatic retries.
with Comfy() as client:
    result = client.models.run(
        "higgsfield/higgsfield-kling-3-4k",
        {
            "aspect_ratio": "16:9",
            "cfg_scale": 0.5,
            "duration": 5,
            "prompt": "A cinematic glass pavilion in a misty pine forest at sunrise",
            "sound": "on",
        },
    )

print(result)
```

```typescript TypeScript theme={null}
import { comfy } from "@comfyorg/sdk";

// Reads COMFY_API_KEY from the environment.
// The SDK automatically creates an idempotency key and reuses it for automatic retries.
const { data } = await comfy.models.run("higgsfield/higgsfield-kling-3-4k", {
  aspect_ratio: "16:9",
  cfg_scale: 0.5,
  duration: 5,
  prompt: "A cinematic glass pavilion in a misty pine forest at sunrise",
  sound: "on",
});

console.log(data);
```

```bash cURL theme={null}
curl https://api.comfy.org/v2/models/higgsfield/higgsfield-kling-3-4k \
  -H "X-API-Key: $COMFY_API_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d "{\"aspect_ratio\": \"16:9\", \"cfg_scale\": 0.5, \"duration\": 5, \"prompt\": \"A cinematic glass pavilion in a misty pine forest at sunrise\", \"sound\": \"on\"}"
```

**Queue and collect later**

The same body, sent to `POST https://api.comfy.org/v2/models/higgsfield/higgsfield-kling-3-4k/requests`. Router answers `201` with a `request_id` as soon as the run is admitted, and the result is collected once it is ready, from this process or another one. [Queued delivery](https://docs.comfy.org/development/comfy-router/queue.md) walks through status, cancellation and collection.

```python Python theme={null}
import asyncio
from comfy_sdk import AsyncComfy

# Reads COMFY_API_KEY from the environment.
# Each submit() call mints its own Idempotency-Key and reuses it for automatic retries.
async def main():
    async with AsyncComfy() as client:
        handle = await client.models.submit(
            "higgsfield/higgsfield-kling-3-4k",
            {
                "aspect_ratio": "16:9",
                "cfg_scale": 0.5,
                "duration": 5,
                "prompt": "A cinematic glass pavilion in a misty pine forest at sunrise",
                "sound": "on",
            },
        )
        print("request_id:", handle.request_id)  # with the model ID, all another process needs

        # Poll until the request completes, waiting the Retry-After the server names.
        async for update in handle.iter_events():
            print(update.status, update.queue_position)

        # The provider's own payload, the same value models.run() returns.
        # A request that failed or was cancelled raises the typed Router error here.
        result = await handle.get()

    print(result)

asyncio.run(main())
```

```typescript TypeScript theme={null}
import { comfy } from "@comfyorg/sdk";

// Reads COMFY_API_KEY from the environment.
// Each submit() call mints its own Idempotency-Key and reuses it for automatic retries.
const handle = await comfy.models.submit("higgsfield/higgsfield-kling-3-4k", {
  aspect_ratio: "16:9",
  cfg_scale: 0.5,
  duration: 5,
  prompt: "A cinematic glass pavilion in a misty pine forest at sunrise",
  sound: "on",
});
console.log("requestId:", handle.requestId); // with the model ID, all another process needs

// Poll until the request completes, waiting the Retry-After the server names.
for await (const update of handle.events()) {
  console.log(update.status, update.queuePosition);
}

// The same result models.run() returns. A request that failed or was cancelled rejects here.
const result = await handle.get();

console.log(result.data);
```

```bash cURL theme={null}
# 1. Submit. Router answers 201 with request_id, status_url, response_url and cancel_url.
curl https://api.comfy.org/v2/models/higgsfield/higgsfield-kling-3-4k/requests \
  -H "X-API-Key: $COMFY_API_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d "{\"aspect_ratio\": \"16:9\", \"cfg_scale\": 0.5, \"duration\": 5, \"prompt\": \"A cinematic glass pavilion in a misty pine forest at sunrise\", \"sound\": \"on\"}"

# 2. Poll until status is COMPLETED, waiting the Retry-After seconds each response names.
REQUEST_ID="<request_id from the 201 body>"
curl -i https://api.comfy.org/v2/models/higgsfield/higgsfield-kling-3-4k/requests/$REQUEST_ID/status \
  -H "X-API-Key: $COMFY_API_KEY"

# 3. Collect. 200 with the model's native output, 202 with the status body while it is still running.
curl https://api.comfy.org/v2/models/higgsfield/higgsfield-kling-3-4k/requests/$REQUEST_ID \
  -H "X-API-Key: $COMFY_API_KEY"
```

## Schema

### Input

**aspect\_ratio** `string` (default: "16:9")

Output aspect ratio.

Possible values: `16:9`, `9:16`, `1:1`

**cfg\_scale** `number` (default: 0.5)

How strongly the generation follows the prompt. Higgsfield documents 0-1 in increments of 0.01, but only the 0-1 bound is declared here: a `multipleOf: 0.01` would be evaluated in binary floating point and would refuse ordinary values such as 0.3, so a finer-grained value is ACCEPTED and forwarded rather than refused, the same way `prompt` caveats its undeclared length ceiling.

Range: `0` to `1`

**duration** `integer` (default: 5)

Output duration in seconds. Supported range: 3-15.

Range: `3` to `15`

**elements** `string[]`

Reusable Kling element ids, for subject consistency across generations.

**multi\_prompt** `object[]`

Ordered shot definitions, used when `multi_shots` is true. 1-6 shots; the per-shot durations are bounded by the task's own total duration, which is not expressible here.

**multi\_prompt\[].duration** `integer`

Duration of this shot in seconds, 1-15. The sum across shots must not exceed the task's total duration, which JSON Schema cannot express; Higgsfield enforces it.

Range: `1` to `15`

**multi\_prompt\[].prompt** `string`

Prompt for this shot. Higgsfield documents a 512-character ceiling.

**multi\_shots** `boolean` (default: false)

Enable a multi-shot sequence. When true, `multi_prompt` carries the per-shot definitions.

**prompt** `string`

Prompt describing the desired output. Higgsfield documents that Kling uses up to the first 2,500 characters and truncates beyond that, so no maxLength is declared — a longer body is accepted, not refused.

**sound** `string` (default: "on")

Enable or disable generated sound.

Possible values: `on`, `off`

Generated from the schema Router serves at `GET /v2/models/higgsfield/higgsfield-kling-3-4k/openapi.json`, the same document it validates a call against before the request reaches the provider.

### Output

**cancel\_url** `string`

Absolute URL used to cancel a request before processing starts.

**error** `string`

Failure detail, set when `status` is `failed`.

**request\_id** `string` *required*

Stable identifier used for polling, cancellation and support.

**status** `string` *required*

Current request state.

Possible values: `queued`, `in_progress`, `nsfw`, `failed`, `completed`, `canceled`

**status\_url** `string`

Absolute URL to poll until the request reaches a terminal state.

**video** `object`

One Higgsfield media output.

**video.url** `string` *required*

Download URL of the generated media.

## Examples

### Input

```json theme={null}
{
  "aspect_ratio": "16:9",
  "cfg_scale": 0.5,
  "duration": 5,
  "prompt": "A cinematic glass pavilion in a misty pine forest at sunrise",
  "sound": "on"
}
```

### Output

```json theme={null}
{
  "cancel_url": "https://api.higgsfield.ai/requests/4b1f8ac2-0d35-4f2e-9c77-1e5a6b0c93d4/cancel",
  "request_id": "4b1f8ac2-0d35-4f2e-9c77-1e5a6b0c93d4",
  "status": "completed",
  "status_url": "https://api.higgsfield.ai/requests/4b1f8ac2-0d35-4f2e-9c77-1e5a6b0c93d4/status",
  "video": {
    "url": "https://example.invalid/higgsfield/higgsfield-kling-3-4k/generated.mp4"
  }
}
```

## Before you ship

The SDKs create an `Idempotency-Key` and reuse it for automatic retries. For manual retries, reuse the original key. Router can hold the connection for up to 10 minutes.

When a request fails, Router sends an `X-Comfy-Error-Type` response header explaining why. A `422` means Router rejected the input before calling the provider, and a `413` means the request body was larger than Router accepts. Download generated assets promptly because [result URLs can expire](https://docs.comfy.org/development/comfy-router/reference.md#result-assets).

Any size limit named in a field description above is the provider's own bound on that field, quoted from the provider's specification. Router applies a separate cap to the whole request body, which base64-encoded media counts against: see [request body size](https://docs.comfy.org/development/comfy-router/limitations.md#request-bodies-are-capped).

This page documents one partner model called through Comfy Router. The same `comfy-sdk` / `@comfyorg/sdk` package also ships a second client, for running a whole ComfyUI workflow graph on Comfy Cloud: `Comfy(api_key=...)` / `new Comfy({ apiKey })`, with `client.workflows`, `client.assets` and `client.jobs`. See [Comfy SDKs](https://docs.comfy.org/development/api-development/sdks.md).

> **[Headers](https://docs.comfy.org/development/comfy-router/headers.md)**
>
> Authentication, idempotency, request IDs, error buckets, retry pacing, spend limits.

> **[Using the Router API](https://docs.comfy.org/development/comfy-router/api.md)**
>
> Model discovery, validation errors, retries, and billing.

> **[Limitations](https://docs.comfy.org/development/comfy-router/limitations.md)**
>
> What Router does not do today, and what to use instead.


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