# MiniMax H3 Max Extend

VIDEOFeaturedminimax-h3-max-extend

**MiniMax H3 Max Extend** continues an existing clip with [MiniMax](https://www.minimaxi.com/)’s H3 Max video model, adding 5 to 15 seconds of new footage after the source from a prompt that describes what happens next. Prompt expansion reads the source video to keep subjects and motion consistent across the cut, and the result is returned as one extended clip at 480p, 768p, 1080p, or 2K, following the source aspect ratio or cropped to one of six from 21:9 to 9:16\. Built for lengthening takes and chaining multi-beat sequences for game trailers without regenerating the shot.

Best for

Continuing an existing clip with 5-15 seconds of new footage, Longer takes that keep the source's subjects and motion, 480p, 768p, 1080p, or 2K output

POST

/v2/workspaces/{workspace\_id}/base-models/minimax-h3-max-extend/inferences

```bash
curl --request POST \
  --url https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/minimax-h3-max-extend/inferences \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "prompt": "a knight standing in a snowy forest",
  "aspect_ratio": "LANDSCAPE_16_9_480p",
  "duration_seconds": 5,
  "guidance_file_init_video": [
    {
      "url": "<file_url>"
    }
  ]
}'
```

```python
import requests


url = "https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/minimax-h3-max-extend/inferences"


payload = {
    "prompt": "a knight standing in a snowy forest",
    "aspect_ratio": "LANDSCAPE_16_9_480p",
    "duration_seconds": 5,
    "guidance_file_init_video": [{ "url": "<file_url>" }]
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}


response = requests.post(url, json=payload, headers=headers)


print(response.json())
```

```js
const url = 'https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/minimax-h3-max-extend/inferences';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"prompt":"a knight standing in a snowy forest","aspect_ratio":"LANDSCAPE_16_9_480p","duration_seconds":5,"guidance_file_init_video":[{"url":"<file_url>"}]}'
};


try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main


import (
  "fmt"
  "strings"
  "net/http"
  "io"
)


func main() {


  url := "https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/minimax-h3-max-extend/inferences"


  payload := strings.NewReader("{\n  \"prompt\": \"a knight standing in a snowy forest\",\n  \"aspect_ratio\": \"LANDSCAPE_16_9_480p\",\n  \"duration_seconds\": 5,\n  \"guidance_file_init_video\": [\n    {\n      \"url\": \"<file_url>\"\n    }\n  ]\n}")


  req, _ := http.NewRequest("POST", url, payload)


  req.Header.Add("Authorization", "Bearer <token>")
  req.Header.Add("Content-Type", "application/json")


  res, _ := http.DefaultClient.Do(req)


  defer res.Body.Close()
  body, _ := io.ReadAll(res.Body)


  fmt.Println(res)
  fmt.Println(string(body))


}
```

```php
<?php


$curl = curl_init();


curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/minimax-h3-max-extend/inferences",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'prompt' => 'a knight standing in a snowy forest',
    'aspect_ratio' => 'LANDSCAPE_16_9_480p',
    'duration_seconds' => 5,
    'guidance_file_init_video' => [
        [
                'url' => '<file_url>'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);


$response = curl_exec($curl);
$err = curl_error($curl);


curl_close($curl);


if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}
```

```java
OkHttpClient client = new OkHttpClient();


MediaType mediaType = MediaType.parse("application/json");
RequestBody body = RequestBody.create(mediaType, "{\n  \"prompt\": \"a knight standing in a snowy forest\",\n  \"aspect_ratio\": \"LANDSCAPE_16_9_480p\",\n  \"duration_seconds\": 5,\n  \"guidance_file_init_video\": [\n    {\n      \"url\": \"<file_url>\"\n    }\n  ]\n}");
Request request = new Request.Builder()
  .url("https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/minimax-h3-max-extend/inferences")
  .post(body)
  .addHeader("Authorization", "Bearer <token>")
  .addHeader("Content-Type", "application/json")
  .build();


Response response = client.newCall(request).execute();
```

```ruby
require 'uri'
require 'net/http'


url = URI("https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/minimax-h3-max-extend/inferences")


http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true


request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"prompt\": \"a knight standing in a snowy forest\",\n  \"aspect_ratio\": \"LANDSCAPE_16_9_480p\",\n  \"duration_seconds\": 5,\n  \"guidance_file_init_video\": [\n    {\n      \"url\": \"<file_url>\"\n    }\n  ]\n}"


response = http.request(request)
puts response.read_body
```

```csharp
var client = new RestClient("https://api.app.layer.ai/api/v2/workspaces/:workspace_id/base-models/minimax-h3-max-extend/inferences");
var request = new RestRequest("", Method.Post);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"prompt\": \"a knight standing in a snowy forest\",\n  \"aspect_ratio\": \"LANDSCAPE_16_9_480p\",\n  \"duration_seconds\": 5,\n  \"guidance_file_init_video\": [\n    {\n      \"url\": \"<file_url>\"\n    }\n  ]\n}", ParameterType.RequestBody);
var response = client.Execute(request);
```

* Layer API

## Authorizations

* **[bearerAuth](/docs/v2/rest-api#bearerauth)**
* **[oauth2](/docs/v2/rest-api#oauth2)**

## Parameters

### Path Parameters

**workspace\_id**

required

_Workspace Id_

Id of the workspace that owns the resource.

string format: uuid

Id of the workspace that owns the resource.

### Query Parameters

**session\_name**

_Session Name_

Organize this run under a named session. A new session is created if none matches.

string

nullable

Organize this run under a named session. A new session is created if none matches.

### Header Parameters

**Idempotency-Key**

string

<= 255 characters

Opaque key making this request safe to retry. The first request with a given key executes; a later request with the same key returns that first response with `Idempotent-Replayed: true` instead of executing again. The key covers the method, path, query, and body it was first used with; reusing it for a different request is rejected with 422\. Replayable for 24 hours.

## Request Bodyrequired

_MiniMax H3 Max Extend_object

**prompt**

required

_Prompt_

string

**aspect\_ratio**

_Aspect Ratio_

string

default: LANDSCAPE\_16\_9\_480p

Allowed values: AUTO LANDSCAPE\_21\_9\_480p LANDSCAPE\_16\_9\_480p LANDSCAPE\_4\_3\_480p SQUARE\_480p PORTRAIT\_3\_4\_480p PORTRAIT\_9\_16\_480p LANDSCAPE\_21\_9\_768p LANDSCAPE\_16\_9\_768p LANDSCAPE\_4\_3\_768p SQUARE\_768p PORTRAIT\_3\_4\_768p PORTRAIT\_9\_16\_768p LANDSCAPE\_21\_9\_1080p LANDSCAPE\_16\_9\_1080p LANDSCAPE\_4\_3\_1080p SQUARE\_1080p PORTRAIT\_3\_4\_1080p PORTRAIT\_9\_16\_1080p LANDSCAPE\_21\_9\_1440p LANDSCAPE\_16\_9\_1440p LANDSCAPE\_4\_3\_1440p SQUARE\_1440p PORTRAIT\_3\_4\_1440p PORTRAIT\_9\_16\_1440p

**seed**

_Seed_

_Advanced field._

integer

nullable

**duration\_seconds**

_Duration_

integer

default: 5

**guidance\_file\_init\_video**

required

_Source video_

The video to modify

Array<object>

\>= 1 items

_InferenceFormFileRef_

A single guidance/reference file supplied to a `reference_image_list` field.

The slot’s guidance `type` is fixed by the field it’s attached to; the caller supplies the file URL and, where the model supports per-file weighting, a weight.

object

**url**

required

_Url_

string

**weight**

_Weight_

number

nullable

**prompt\_language**

_Prompt Language_

_Advanced field._

string

nullable

##### Example

```json
{
  "prompt": "a knight standing in a snowy forest",
  "aspect_ratio": "LANDSCAPE_16_9_480p",
  "duration_seconds": 5,
  "guidance_file_init_video": [
    {
      "url": "<file_url>"
    }
  ]
}
```

## Responses

### 202

Successful Response

_ExecuteForgeOutput_object

**inference\_id**

required

_Inference Id_

Unique identifier for this forge run.

string format: uuid

**status**

required

_InferenceStatus_

Current status: IN\_PROGRESS.

string

Allowed values: in\_progress complete failed cancelled deleted

**estimated\_price\_creative\_units**

_Estimated Price Creative Units_

Estimated price in Creative Units.

number

nullable

**poll\_interval\_seconds**

required

_Poll Interval Seconds_

Suggested polling interval in seconds.

integer

**created\_at**

required

_Created At_

Timestamp of when the run was created.

string format: date-time

**session\_id**

_Session Id_

Session ID the run was added to, if a session was specified.

string format: uuid

nullable

**normalized\_parameters**

Any of:

**NormalizedInferenceParameters**

_NormalizedInferenceParameters_

Inference parameters after model-specific normalization.

These reflect the actual values used for generation, including model defaults applied for any parameters not explicitly set.

object

**width**

_Width_

Resolved output width in pixels.

integer

nullable

**height**

_Height_

Resolved output height in pixels.

integer

nullable

**batch\_size**

_Batch Size_

Number of outputs to generate.

integer

nullable

**num\_inference\_steps**

_Num Inference Steps_

Resolved number of diffusion steps.

integer

nullable

**guidance\_scale**

_Guidance Scale_

Resolved guidance scale.

number

nullable

**duration\_seconds**

_Duration Seconds_

Resolved output length in seconds — video duration or audio clip length.

number

nullable

**fps**

_Fps_

Resolved FPS.

integer

nullable

**null**

null

##### Example

```json
{
  "status": "in_progress"
}
```

### 401

Unauthenticated — missing or invalid Bearer token.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 403

Forbidden — insufficient permissions, or the access token lacks the scope the operation requires.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 404

Resource not found.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 409

The request with this `Idempotency-Key` is still running — retry after the number of seconds in `Retry-After`.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 422

Invalid input parameters, or an `Idempotency-Key` reused for a different request.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 429

Rate limited — retry after the number of seconds in `Retry-After`.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```

### 500

Internal server error.

object

**type**

required

string

**title**

required

string

**status**

required

integer

**detail**

required

string

##### Example

```json
{
  "type": "https://api.layer.ai/errors/ERROR_CODE",
  "title": "Error Title",
  "status": 400,
  "detail": "Human-readable description."
}
```