Calculate crop API

Calculate the crop box that fits an image to a social media size.

• Endpoint: POST https://postboost.co/app/api/tools/social-media-image-sizes/crop (operationId calculateCrop)
• Web tool: postboost.co/tools/social-media-image-sizes
• Token: optional (limits)
• MCP: tool calculate-crop on https://postboost.co/mcp/tools

Request

Field	Type	Default	Description
width	integer		Source image width in pixels.
height	integer		Source image height in pixels.
network	string		Network key from getImageSizes (network_key), e.g. instagram. With format, picks the target size.
format	string		Format key from getImageSizes (format_key), e.g. feed-square.
target_width	integer		Target width in pixels, instead of network + format.
target_height	integer		Target height in pixels, instead of network + format.
fit	string: cover, contain	"cover"	cover crops to fill the target; contain keeps the whole image and centres it.

Call it

curl

curl -X POST https://postboost.co/app/api/tools/social-media-image-sizes/crop \
  -H 'Content-Type: application/json' \
  -d '{"width":4000,"height":3000,"network":"instagram","format":"feed-square"}'

Python

from postboost import ApiClient, Configuration
from postboost.api.free_tools_api import FreeToolsApi
from postboost.models import FreeToolCalculateCropRequest

with ApiClient(Configuration()) as client:
    api = FreeToolsApi(client)
    result = api.calculate_crop(FreeToolCalculateCropRequest.from_dict({"width": 4000, "height": 3000, "network": "instagram", "format": "feed-square"}))
    print(result.to_dict())

Node.js

import { FreeToolsApi } from 'postboost';

const api = new FreeToolsApi();
const { body } = await api.calculateCrop({ width: 4000, height: 3000, network: "instagram", format: "feed-square" });
console.log(body);

PHP

use PostBoostClient\Api\FreeToolsApi;
use PostBoostClient\Model\FreeToolCalculateCropRequest;

$api = new FreeToolsApi(new GuzzleHttp\Client());
$result = $api->calculateCrop(new FreeToolCalculateCropRequest(['width' => 4000, 'height' => 3000, 'network' => "instagram", 'format' => "feed-square"]));
echo $result;

Go

import (
    "context"
    "encoding/json"
    "fmt"

    postboost "github.com/postboost-co/postboost-go"
)

var request postboost.FreeToolCalculateCropRequest
if err := json.Unmarshal([]byte(`{"width":4000,"height":3000,"network":"instagram","format":"feed-square"}`), &request); err != nil {
    panic(err)
}

client := postboost.NewAPIClient(postboost.NewConfiguration())
result, _, err := client.FreeToolsAPI.CalculateCrop(context.Background()).FreeToolCalculateCropRequest(request).Execute()
fmt.Println(result, err)

Ruby

require 'postboost'

api = PostBoost::FreeToolsApi.new
result = api.calculate_crop(PostBoost::FreeToolCalculateCropRequest.new({ width: 4000, height: 3000, network: "instagram", format: "feed-square" }))
puts result.to_hash

Java

import com.postboost.ApiClient;
import com.postboost.api.FreeToolsApi;
import com.postboost.model.FreeToolCalculateCropRequest;
import com.postboost.model.FreeToolCalculateCropResponse;

FreeToolsApi api = new FreeToolsApi(new ApiClient());
FreeToolCalculateCropRequest request = FreeToolCalculateCropRequest.fromJson("{\"width\":4000,\"height\":3000,\"network\":\"instagram\",\"format\":\"feed-square\"}");
FreeToolCalculateCropResponse result = api.calculateCrop(request);
System.out.println(result.toJson());

C#

using Newtonsoft.Json;
using PostBoost.Client.Api;
using PostBoost.Client.Client;
using PostBoost.Client.Model;

var api = new FreeToolsApi(new Configuration());
var request = JsonConvert.DeserializeObject<FreeToolCalculateCropRequest>(@"{""width"":4000,""height"":3000,""network"":""instagram"",""format"":""feed-square""}");
var result = await api.CalculateCropAsync(request);
Console.WriteLine(result.ToJson());

Rust

use postboost::apis::configuration::Configuration;
use postboost::apis::free_tools_api;
use postboost::models::FreeToolCalculateCropRequest;

let config = Configuration::new();
let request: FreeToolCalculateCropRequest = serde_json::from_str(r##"{"width":4000,"height":3000,"network":"instagram","format":"feed-square"}"##)?;
let result = free_tools_api::calculate_crop(&config, request).await?;
println!("{:?}", result);

CLI

echo '{"width":4000,"height":3000,"network":"instagram","format":"feed-square"}' | ./postboost-cli --content-type application/json calculateCrop -

With a token, send Authorization: Bearer YOUR_API_TOKEN as a default header (how, per SDK).

Response

{
    "crop": {
        "x": 500,
        "y": 0,
        "width": 3000,
        "height": 3000
    },
    "output": {
        "width": 1080,
        "height": 1080
    },
    "image": {
        "x": 0,
        "y": 0,
        "width": 1080,
        "height": 1080
    },
    "scale": 0.36,
    "upscaled": false
}

With MCP

Connect https://postboost.co/mcp/tools (setup) and ask, for example: Calculate the crop box that fits an image to a social media size with the PostBoost calculate-crop tool.

Errors

Status	When
401	The Authorization header holds an invalid token. Leave it out to call as a guest.
413	The JSON body is larger than 128 KB.
422	A field is invalid; the body lists the errors per field.
429	A limit is reached; see limits.