Name: Riffusion API: AI Text to Music Generator
Brand: magicapi
SKU: api-magicapi-real-time-music-generation-riffusion-riffusion
Availability: InStock
Author: API Market

Shashank Agarwal

# 🎵 Text-to-Music Generator API (Riffusion)

## Overview
Riffusion generates music with Stable Diffusion. Its developer describes it as Stable Diffusion for real-time music generation: the model creates a spectrogram image from your prompt and turns it into audio.

Send a text `prompt_a` that describes the music. Add `prompt_b` and `alpha` to blend two prompts. Each request returns a WAV audio file and the spectrogram image it was made from.

## Features
- **Text to music**: describe the sound in `prompt_a`, for example a genre or an instrument.
- **Blend two prompts**: set `prompt_b` and choose the mix with `alpha` (0 uses `prompt_a` fully, 1 uses `prompt_b` fully).
- **Seed spectrograms**: start from one of 11 seed spectrograms (`seed_image_id`, default `vibes`).
- **Denoising**: `denoising` (0 to 1, default 0.75) sets how much the seed spectrogram is transformed.
- **Two outputs**: a WAV audio URL and a JPEG spectrogram URL.

## Use Cases
1. **Music sketches**: quick musical ideas in a given style for producers and songwriters.
2. **Background audio**: short music clips for videos, games and prototypes.
3. **Style blends**: clips that mix two genres, such as a synth solo and 90's rap.
4. **Audio visuals**: the spectrogram image for visualizers or educational content about sound.

## Visual Examples
### Example Input
`prompt_a` "funky synth solo" blended with `prompt_b` "90's rap" at `alpha` 0.5, starting from the `vibes` seed spectrogram with `denoising` 0.75 and 50 inference steps.

```json
{
  "alpha": 0.5,
  "prompt_a": "funky synth solo",
  "prompt_b": "90's rap",
  "denoising": 0.75,
  "seed_image_id": "vibes",
  "num_inference_steps": 50
}
```

### Example Output
[Listen to the example output](https://blog.api.market/wp-content/uploads/2026/10/riffusion-output-1-tc8xf8md-api-market-1.wav)

Spectrogram returned with the audio:

![Riffusion output: spectrogram of the generated music clip](https://blog.api.market/wp-content/uploads/2026/10/riffusion-output-2-tc8xf8md-api-market.jpg)

## Input Parameters
| Field | Type | Required | Default | Allowed values | Description |
| --- | --- | --- | --- | --- | --- |
| `prompt_a` | string | No | `funky synth solo` |  | The prompt for your audio |
| `denoising` | number | No | `0.75` | `0` to `1` | How much to transform the input spectrogram |
| `prompt_b` | string | No | none |  | Second prompt to interpolate with the first. Leave it out for no interpolation |
| `alpha` | number | No | `0.5` | `0` to `1` | Interpolation alpha when using two prompts. 0 uses prompt_a fully, 1 uses prompt_b fully |
| `num_inference_steps` | integer | No | `50` | minimum `1` | Number of steps to run the diffusion model |
| `seed_image_id` | string | No | `vibes` | `agile`, `marim`, `mask_beat_lines_80`, `mask_gradient_dark`, `mask_gradient_top_70`, `mask_graident_top_fifth_75`, `mask_top_third_75`, `mask_top_third_95`, `motorway`, `og_beat`, `vibes` | Seed spectrogram to use |

No field is required. If you send no `prompt_a`, the model uses its default prompt `funky synth solo`.

## Pricing
- **Pay As You Go (PAYG) pricing**: you only pay for what you use.
- **Price**: $0.064 per API unit.
- **1 API unit = 1 request with up to 256 seconds of processing.** A request that takes longer uses one unit per started block of 256 seconds (for example, 300 seconds of processing uses 2 units, $0.128).
- Processing time grows with `num_inference_steps`.
- **Example cost**: the example took 19.9 seconds of processing, which is 1 unit, $0.064.
- **Failed or cancelled predictions are not billed.**
- **GET requests to check prediction status** are free and don't count toward API unit usage.
- **No monthly subscription fee.**

## API Documentation

### Base URL
All API requests go to: `https://prod.api.market/api/v1/magicapi/real-time-music-generation-riffusion-riffusion`

### Authentication
Send your api.market API key in the `x-api-market-key` header:
```
x-api-market-key: YOUR_API_MARKET_KEY
```

### Asynchronous Processing
**IMPORTANT**: This API is asynchronous. The flow is:
1. Send a POST request to `/predictions`. A successful request returns **201 Created** with a prediction `id` and a `status` of `starting` or `processing`.
2. Poll GET `/predictions/{id}` with that ID.
3. Keep polling while `status` is `starting` or `processing`.
4. Stop when `status` is `succeeded` (read `output`), `failed` or `canceled` (read `error`).

A polling interval of 1 second and an overall timeout of 600 seconds (10 minutes) work well.

### Endpoints

#### Create a Prediction
```bash
curl -X POST "https://prod.api.market/api/v1/magicapi/real-time-music-generation-riffusion-riffusion/predictions" \
  -H "Content-Type: application/json" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY" \
  -d '{
    "version": "8cf61ea6c56afd61d8f5b9ffd14d7c216c0a93844ce2d82ac1c9ecc9c7f24e05",
    "input": {
      "alpha": 0.5,
      "prompt_a": "funky synth solo",
      "prompt_b": "90'\''s rap",
      "denoising": 0.75,
      "seed_image_id": "vibes",
      "num_inference_steps": 50
    }
  }'
```

Response (201 Created):
```json
{
  "id": "tc8xf8mdthrga0d1ccxaytw3fg",
  "version": "8cf61ea6c56afd61d8f5b9ffd14d7c216c0a93844ce2d82ac1c9ecc9c7f24e05",
  "status": "starting",
  "created_at": "2026-10-22T10:49:04.468Z"
}
```

#### Check Prediction Status
```bash
curl -X GET "https://prod.api.market/api/v1/magicapi/real-time-music-generation-riffusion-riffusion/predictions/{id}" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY"
```

Response when the prediction has finished (200 OK):
```json
{
  "id": "tc8xf8mdthrga0d1ccxaytw3fg",
  "status": "succeeded",
  "output": {
    "audio": "https://blog.api.market/wp-content/uploads/2026/10/riffusion-output-1-tc8xf8md-api-market-1.wav",
    "spectrogram": "https://blog.api.market/wp-content/uploads/2026/10/riffusion-output-2-tc8xf8md-api-market.jpg"
  },
  "error": null,
  "created_at": "2026-10-22T10:49:04.468Z",
  "started_at": "2026-10-22T10:52:38.608Z",
  "completed_at": "2026-10-22T10:52:58.491Z"
}
```

`output` is an object with two URLs: `audio` (the WAV file) and `spectrogram` (the JPEG spectrogram image).

### Status Codes
- **201 Created**: prediction created (POST `/predictions`). This is the normal success response.
- **200 OK**: prediction details returned (GET `/predictions/{id}`).
- **400 Bad Request**: invalid input, for example an `alpha` above 1 or a `seed_image_id` that is not in the list.
- **401 Unauthorized**: missing or invalid API key.
- **404 Not Found**: no prediction with that ID.
- **429 Too Many Requests**: rate limit exceeded.
- **500 Internal Server Error** or **503 Service Unavailable**: temporary server problem; retry later.

## Rate Limits
All plans allow 10 requests per second. Requests above that return `429 Too Many Requests`; back off before retrying and honour any `Retry-After` header. Polling a prediction with GET is free but still counts toward the per-second limit, so poll every 1 to 5 seconds rather than in a tight loop.

## Error Handling
- Check the HTTP status code of every request and read the response body for the error message.
- A prediction can also end with `status` set to `failed`; the `error` field then explains why. Failed predictions are not billed.
- Retry 429, 500 and 503 responses with exponential backoff. Fix the input before retrying a 400.

## Implementation Guide
### Example Code

#### JavaScript
```javascript
const apiKey = "YOUR_API_MARKET_KEY";
const baseUrl = "https://prod.api.market/api/v1/magicapi/real-time-music-generation-riffusion-riffusion";

async function createAndWaitForPrediction(input) {
  const response = await fetch(`${baseUrl}/predictions`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-api-market-key": apiKey
    },
    body: JSON.stringify({ version: "8cf61ea6c56afd61d8f5b9ffd14d7c216c0a93844ce2d82ac1c9ecc9c7f24e05", input })
  });

  if (response.status !== 201) {
    throw new Error(`API error: ${response.status} ${await response.text()}`);
  }

  const prediction = await response.json();
  return pollForResults(prediction.id);
}

const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function pollForResults(predictionId) {
  const maxTimeout = 600000;
  const pollInterval = 1000;
  const startTime = Date.now();

  while (Date.now() - startTime < maxTimeout) {
    const response = await fetch(`${baseUrl}/predictions/${predictionId}`, {
      headers: { "x-api-market-key": apiKey }
    });

    if (!response.ok) {
      throw new Error(`API error: ${response.status} ${await response.text()}`);
    }

    const prediction = await response.json();

    if (prediction.status === "succeeded") {
      return prediction.output;
    }

    if (prediction.status === "failed" || prediction.status === "canceled") {
      throw new Error(`Prediction ${prediction.status}: ${prediction.error || "Unknown error"}`);
    }

    await delay(pollInterval);
  }

  throw new Error("Prediction timed out after 10 minutes");
}

createAndWaitForPrediction({
  "alpha": 0.5,
  "prompt_a": "funky synth solo",
  "prompt_b": "90's rap",
  "denoising": 0.75,
  "seed_image_id": "vibes",
  "num_inference_steps": 50
}).then((output) => console.log(output));
```

#### Python
```python
import time
import requests

API_KEY = "YOUR_API_MARKET_KEY"
BASE_URL = "https://prod.api.market/api/v1/magicapi/real-time-music-generation-riffusion-riffusion"


def create_and_wait_for_prediction(input_data):
    headers = {"Content-Type": "application/json", "x-api-market-key": API_KEY}
    response = requests.post(
        f"{BASE_URL}/predictions",
        headers=headers,
        json={"version": "8cf61ea6c56afd61d8f5b9ffd14d7c216c0a93844ce2d82ac1c9ecc9c7f24e05", "input": input_data},
    )

    if response.status_code != 201:
        raise Exception(f"API error: {response.status_code} {response.text}")

    return poll_for_results(response.json()["id"])


def poll_for_results(prediction_id):
    max_timeout = 600
    poll_interval = 1
    headers = {"x-api-market-key": API_KEY}
    start_time = time.time()

    while time.time() - start_time < max_timeout:
        response = requests.get(f"{BASE_URL}/predictions/{prediction_id}", headers=headers)

        if response.status_code != 200:
            raise Exception(f"API error: {response.status_code} {response.text}")

        prediction = response.json()

        if prediction["status"] == "succeeded":
            return prediction["output"]

        if prediction["status"] in ("failed", "canceled"):
            raise Exception(f"Prediction {prediction['status']}: {prediction.get('error') or 'Unknown error'}")

        time.sleep(poll_interval)

    raise Exception("Prediction timed out after 10 minutes")


print(create_and_wait_for_prediction({
    "alpha": 0.5,
    "prompt_a": "funky synth solo",
    "prompt_b": "90's rap",
    "denoising": 0.75,
    "seed_image_id": "vibes",
    "num_inference_steps": 50
}))
```

## FAQ
- **What does the response contain?**
  - An object with `audio`, the URL of a WAV file, and `spectrogram`, the URL of the spectrogram image the audio was made from.
- **How do I blend two styles?**
  - Send `prompt_b` with the second style and set `alpha`. 0 uses `prompt_a` fully, 1 uses `prompt_b` fully, and 0.5 mixes both.
- **What is `seed_image_id`?**
  - The seed spectrogram the model starts from. Choose one of the 11 values; `denoising` sets how much it is transformed.
- **How much does one clip cost?**
  - $0.064 for a request with up to 256 seconds of processing. The example took 19.9 seconds.
- **What if my prediction fails?**
  - Failed predictions are not billed. Read the `error` field, adjust the input and try again.

## Contact Us
If you have any questions, reach out to us through the chat on the bottom right of the page. You can also email our support team at hello@magicapi.com.


Generate music clips from text prompts with Riffusion, which applies Stable Diffusion to spectrograms. Pay as you go, no monthly fee.