Name: ControlNet Scribble API: Turn Sketches into Images
Brand: magicapi
SKU: api-magicapi-image-from-scribble-generator-jagilley-controlnet-scribble
Availability: InStock
Author: API Market

Shashank Agarwal

# ✏️ Scribble-to-Image Generator API (jagilley ControlNet Scribble)

## Overview
ControlNet Scribble generates detailed images from scribbled drawings. Send a simple drawing as `image` and describe the picture you want in `prompt`; the model keeps the shapes and layout of the drawing and fills in the detail.

`a_prompt` is added to your prompt (default "best quality, extremely detailed") and `n_prompt` lists what to avoid. You can ask for 1 or 4 images per request at 256, 512 or 768 resolution. The response is a list of image URLs: the control map made from your scribble, followed by the generated images.

## Features
- **Drawing-guided generation**: the generated image follows the lines of the scribble in `image`.
- **1 or 4 images per request**: `num_samples` is the string `"1"` (default) or `"4"`.
- **Three resolutions**: `image_resolution` is `"256"`, `"512"` (default) or `"768"`.
- **Prompt helpers**: `a_prompt` appends quality terms; `n_prompt` holds the negative prompt.
- **Sampling controls**: `ddim_steps` (default 20), guidance `scale` (0.1 to 30, default 9), `eta` and `seed`.

## Use Cases
1. **Sketch to illustration**: turn quick drawings into finished images for storyboards, concept art and slides.
2. **Design mockups**: sketch the layout of a product or scene and render it from a prompt.
3. **Drawing apps**: let users scribble on a canvas and get a detailed image back.
4. **Game and app assets**: draw rough shapes of characters or objects and render them from a prompt.

## Visual Examples
### Example Input
Input scribble:

![Example scribble input for the ControlNet Scribble API](https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-input-api-market.png)

Prompt: "a photo of a brightly colored turtle", one sample at 512 resolution:

```json
{
  "image": "https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-input-api-market.png",
  "scale": 9,
  "prompt": "a photo of a brightly colored turtle",
  "a_prompt": "best quality, extremely detailed",
  "n_prompt": "longbody, lowres, bad anatomy, bad hands, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality",
  "ddim_steps": 20,
  "num_samples": "1",
  "image_resolution": "512"
}
```

### Example Output
The request returned two images: the control map made from the scribble, then the generated image.

![Control map made from the scribble by the ControlNet Scribble API](https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-output-1-8tz3fyw5-api-market.png)

![Brightly colored turtle generated from the scribble by the ControlNet Scribble API](https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-output-2-8tz3fyw5-api-market.png)

## Input Parameters
| Field | Type | Required | Default | Allowed values | Description |
| --- | --- | --- | --- | --- | --- |
| `image` | string (URL) | Yes | none |  | Scribbled drawing to follow (URL to a jpeg, png, gif or webp image) |
| `prompt` | string | Yes | none |  | Prompt for the model |
| `num_samples` | string | No | `1` | `1`, `4` | Number of images to generate (higher values may run out of memory) |
| `image_resolution` | string | No | `512` | `256`, `512`, `768` | Resolution of the generated image |
| `ddim_steps` | integer | No | `20` |  | Number of DDIM steps |
| `scale` | number | No | `9` | 0.1 to 30 | Guidance scale |
| `seed` | integer | No | none |  | Random seed |
| `eta` | number | No | `0` |  | DDIM eta |
| `a_prompt` | string | No | `best quality, extremely detailed` |  | Text added to the prompt |
| `n_prompt` | string | No | `longbody, lowres, bad anatomy, bad hands, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality` |  | Negative prompt |

## Pricing
- **Pay As You Go (PAYG) pricing**: you only pay for what you use.
- **Price**: $0.075 per API unit.
- **1 API unit = 1 successful request that finishes within 48 seconds of processing.** A request that takes longer is billed 1 unit for each started 48 seconds of processing time (for example, 49 seconds of processing = 2 units = $0.15).
- The example request below took 4.3 seconds of processing, so it cost $0.075 (1 unit).
- `num_samples` "4", higher `image_resolution` or more `ddim_steps` take longer, so they can use more units.
- **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/image-from-scribble-generator-jagilley-controlnet-scribble`

### 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. The example request took about 4 seconds of processing.

### Endpoints

#### Create a Prediction
```bash
curl -X POST "https://prod.api.market/api/v1/magicapi/image-from-scribble-generator-jagilley-controlnet-scribble/predictions" \
  -H "Content-Type: application/json" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY" \
  -d '{
    "version": "435061a1b5a4c1e26740464bf786efdfa9cb3a3ac488595a2de23e143fdb0117",
    "input": {
      "image": "https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-input-api-market.png",
      "scale": 9,
      "prompt": "a photo of a brightly colored turtle",
      "a_prompt": "best quality, extremely detailed",
      "n_prompt": "longbody, lowres, bad anatomy, bad hands, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality",
      "ddim_steps": 20,
      "num_samples": "1",
      "image_resolution": "512"
    }
  }'
```

Response (201 Created):
```json
{
  "id": "8tz3fyw5y5rn80d1ccsbf63948",
  "version": "435061a1b5a4c1e26740464bf786efdfa9cb3a3ac488595a2de23e143fdb0117",
  "status": "starting",
  "created_at": "2026-10-22T10:40:18.111Z"
}
```

#### Check Prediction Status
```bash
curl -X GET "https://prod.api.market/api/v1/magicapi/image-from-scribble-generator-jagilley-controlnet-scribble/predictions/{id}" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY"
```

Response when the prediction has finished (200 OK):
```json
{
  "id": "8tz3fyw5y5rn80d1ccsbf63948",
  "status": "succeeded",
  "output": [
    "https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-output-1-8tz3fyw5-api-market.png",
    "https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-output-2-8tz3fyw5-api-market.png"
  ],
  "error": null,
  "created_at": "2026-10-22T10:40:18.111Z",
  "started_at": "2026-10-22T10:41:58.797Z",
  "completed_at": "2026-10-22T10:42:03.137Z"
}
```

`output` is a list of image URLs. The first URL is the control map made from the scribble; the generated images follow (one with `num_samples` "1", four with "4").

### 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 a missing `image` or `prompt`, or a `num_samples` other than "1" or "4".
- **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/image-from-scribble-generator-jagilley-controlnet-scribble";

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: "435061a1b5a4c1e26740464bf786efdfa9cb3a3ac488595a2de23e143fdb0117", 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({
    "image": "https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-input-api-market.png",
    "scale": 9,
    "prompt": "a photo of a brightly colored turtle",
    "a_prompt": "best quality, extremely detailed",
    "n_prompt": "longbody, lowres, bad anatomy, bad hands, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality",
    "ddim_steps": 20,
    "num_samples": "1",
    "image_resolution": "512"
  }).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/image-from-scribble-generator-jagilley-controlnet-scribble"


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": "435061a1b5a4c1e26740464bf786efdfa9cb3a3ac488595a2de23e143fdb0117", "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({
    "image": "https://blog.api.market/wp-content/uploads/2026/10/controlnet-scribble-input-api-market.png",
    "scale": 9,
    "prompt": "a photo of a brightly colored turtle",
    "a_prompt": "best quality, extremely detailed",
    "n_prompt": "longbody, lowres, bad anatomy, bad hands, missing fingers, extra digit, fewer digits, cropped, worst quality, low quality",
    "ddim_steps": 20,
    "num_samples": "1",
    "image_resolution": "512"
}))
```

## FAQ
- **Why does a request with one sample return two images?**
  - The first URL is the control map the model made from your scribble. The generated image follows it, as in the example.
- **Why are `num_samples` and `image_resolution` strings?**
  - The schema defines them as string enums: `num_samples` is `"1"` or `"4"`, `image_resolution` is `"256"`, `"512"` or `"768"`. Send them in quotes.
- **What is `a_prompt`?**
  - Text added to your `prompt`. The default is "best quality, extremely detailed".
- **What kind of drawing works?**
  - A simple scribble with clear lines, like the example input. The model follows its shapes and layout.
- **How much does a request cost?**
  - $0.075 per API unit, and one unit covers up to 48 seconds of processing. The example took about 4.3 seconds and cost $0.075.
- **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 detailed images from scribbled drawings and a text prompt with ControlNet Scribble. $0.075 per API unit, pay as you go.