API reference · Mirelo

mirelo/sfx1.6/extend-audio

Integrate this model through SandBase's unified API, with production-ready schemas and examples.

IMAGEAsyncOpen model

Production endpoint

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OpenAI-compatible endpoint with unified authentication and usage tracking.

POSThttps://api.sandbase.ai/v1/run

Model IDmirelo/sfx1.6/extend-audio

Input Schema

8 parameters · 0 required · 8 optional

Parameter	Type	Required	Description
`seed`	integer	Optional	Seed for generation. -1 or None for random. · Min: -1
`audio`	string	Optional	URL of the audio prefix to extend. The prefix duration must be 3–59 seconds; the total output (prefix + append_duration) is capped at 60 seconds.
`ambience`	boolean	Optional	When true, run the extend+loop path: extend the prefix and stitch the end back to the prefix start so the tile loops seamlessly. When false, run a one-shot extension. · Default: false
`num_samples`	integer	Optional	Number of variations to generate. · Min: 1 · Max: 4 · Default: 1
`text_prompt`	string	Optional	Optional text prompt guiding the extension.
`double_output`	boolean	Optional	Only used when ambience=true: concatenate the loop with itself for a 2x-length output. · Default: false
`append_duration`	number	Optional	How many seconds to add after the prefix. Total output = prefix duration + append_duration, capped at 60s. Minimum 1s, maximum 57s (60s cap minus the 3s prefix minimum). · Min: 1 · Max: 57 · Default: 10
`upload_audio_format`	string	Optional	Audio format for the returned files. · Options: wav, mp3, aac, flac · Default: "wav" wavmp3aacflac

Output Schema

Field	Type	Description
`id`	string	Unique identifier for the generation task
`status`	string	Task status: pending, running, completed, failed, timeout
`model`	string	Model used for the generation
`outputs`	array	Array of output items
`outputs[].url`	string	URL of the generated artifact
`outputs[].content_type`	string	MIME type (e.g. image/png, video/mp4)
`error`	object \| null	Error details if failed, null on success
`error.type`	string	Machine-readable error type code
`error.message`	string	Human-readable error description

Async Workflow

This model uses asynchronous execution. Submit a request and poll for the result.

Submit — POST to /v1/run, receive an id
Poll — GET /v1/run/{id} until status is completed, failed, or timeout
Retrieve — Read outputs from the completed response

Code Examples

Ready-to-run snippets

const apiKey = process.env.SANDBASE_API_KEY;
const response = await fetch("https://api.sandbase.ai/v1/run", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "mirelo/sfx1.6/extend-audio",
    "audio": "https://static.sandbase.ai/examples/mirelo/sfx1.6/extend-audio/input_audio_0.aac",
    "ambience": false,
    "num_samples": 1,
    "text_prompt": "birds chirping",
    "double_output": false,
    "append_duration": 10,
    "upload_audio_format": "wav"
  }),
});

if (!response.ok) throw new Error(await response.text());
let result = await response.json();
for (let attempt = 0; attempt < 120 && !["completed", "failed", "timeout"].includes(result.status); attempt++) {
  await new Promise((resolve) => setTimeout(resolve, 2_000));
  const poll = await fetch(`https://api.sandbase.ai/v1/run/${result.id}`, {
    headers: { Authorization: `Bearer ${apiKey}` },
  });
  if (!poll.ok) throw new Error(await poll.text());
  result = await poll.json();
}
if (result.status !== "completed") throw new Error(`Generation ended: ${result.status}`);
console.log(result);

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