Bounding Box

Bounding Box tasks identify and locate objects within an image by drawing rectangular bounding boxes around them. The solution returns a list of boxes, each defined by position and dimensions. This is used for CAPTCHAs that ask users to draw rectangles around specific objects.

Task Type

Type	Description
`BoundingBoxTask`	Draw bounding boxes around objects in an image

Parameters

Parameter	Type	Required	Description
`type`	string	Yes	`BoundingBoxTask`
`body`	string	Yes	Base64-encoded image
`comment`	string	No	Instructions (e.g., “Draw boxes around all cars”)

Create Task

Request

{
  "clientKey": "YOUR_API_KEY",
  "task": {
    "type": "BoundingBoxTask",
    "body": "iVBORw0KGgoAAAANSUhEUg...",
    "comment": "Draw boxes around all cars"
  }
}

Response

{
  "errorId": 0,
  "status": "ready",
  "solution": {
    "boxes": [
      { "x": 10, "y": 20, "width": 100, "height": 80 },
      { "x": 200, "y": 50, "width": 120, "height": 90 }
    ]
  }
}

Solution Object

{
  "boxes": [
    { "x": 10, "y": 20, "width": 100, "height": 80 },
    { "x": 200, "y": 50, "width": 120, "height": 90 }
  ]
}

Field	Type	Description
`boxes`	array	Array of bounding box objects

Each bounding box object contains:

Field	Type	Description
`x`	integer	Horizontal pixel position of the top-left corner
`y`	integer	Vertical pixel position of the top-left corner
`width`	integer	Width of the bounding box in pixels
`height`	integer	Height of the bounding box in pixels

Code Examples

Python

import requests
import base64

API_KEY = "YOUR_API_KEY"

with open("captcha.png", "rb") as f:
    image_data = base64.b64encode(f.read()).decode()

response = requests.post("https://api.ucaptcha.net/createTask", json={
    "clientKey": API_KEY,
    "task": {
        "type": "BoundingBoxTask",
        "body": image_data,
        "comment": "Draw boxes around all cars"
    }
}).json()

if response.get("status") == "ready":
    boxes = response["solution"]["boxes"]
    for box in boxes:
        print(f"Box at ({box['x']}, {box['y']}) size {box['width']}x{box['height']}")
else:
    import time
    task_id = response["taskId"]
    while True:
        result = requests.post("https://api.ucaptcha.net/getTaskResult", json={
            "clientKey": API_KEY,
            "taskId": task_id
        }).json()

        if result["status"] == "ready":
            boxes = result["solution"]["boxes"]
            for box in boxes:
                print(f"Box at ({box['x']}, {box['y']}) size {box['width']}x{box['height']}")
            break
        elif result["status"] == "failed":
            print("Error:", result.get("errorDescription"))
            break

        time.sleep(5)

JavaScript

import { readFileSync } from "fs";

const API_KEY = "YOUR_API_KEY";

const imageData = readFileSync("captcha.png").toString("base64");

const response = await fetch("https://api.ucaptcha.net/createTask", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    clientKey: API_KEY,
    task: {
      type: "BoundingBoxTask",
      body: imageData,
      comment: "Draw boxes around all cars"
    }
  })
}).then(r => r.json());

if (response.status === "ready") {
  for (const box of response.solution.boxes) {
    console.log(`Box at (${box.x}, ${box.y}) size ${box.width}x${box.height}`);
  }
} else {
  const taskId = response.taskId;
  while (true) {
    const result = await fetch("https://api.ucaptcha.net/getTaskResult", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ clientKey: API_KEY, taskId })
    }).then(r => r.json());

    if (result.status === "ready") {
      for (const box of result.solution.boxes) {
        console.log(`Box at (${box.x}, ${box.y}) size ${box.width}x${box.height}`);
      }
      break;
    } else if (result.status === "failed") {
      console.error("Error:", result.errorDescription);
      break;
    }

    await new Promise(r => setTimeout(r, 5000));
  }
}

cURL

IMAGE_BASE64=$(base64 -w 0 captcha.png)

curl -X POST https://api.ucaptcha.net/createTask \
  -H "Content-Type: application/json" \
  -d "{
    \"clientKey\": \"YOUR_API_KEY\",
    \"task\": {
      \"type\": \"BoundingBoxTask\",
      \"body\": \"$IMAGE_BASE64\",
      \"comment\": \"Draw boxes around all cars\"
    }
  }"

# Poll for result if not immediately ready (replace TASK_ID)
curl -X POST https://api.ucaptcha.net/getTaskResult \
  -H "Content-Type: application/json" \
  -d '{
    "clientKey": "YOUR_API_KEY",
    "taskId": "TASK_ID"
  }'

Provider Coverage

2Captcha