A familiar request, so the move can stay small.

curl -H "X-Api-Key: $REMOVER_API_KEY" \
  -F "image_file=@image.png" \
  -F "size=auto" \
  -o no-bg.png \
  https://remover.dev/v1.0/removebg

import { readFile, writeFile } from "node:fs/promises";

const body = new FormData();
body.set("image_file", new Blob([await readFile("image.png")]), "image.png");
body.set("size", "auto");
const response = await fetch("https://remover.dev/v1.0/removebg", {
  method: "POST",
  headers: { "X-Api-Key": process.env.REMOVER_API_KEY },
  body,
});
if (!response.ok) throw new Error(await response.text());
await writeFile("no-bg.png", Buffer.from(await response.arrayBuffer()));

import os, requests

response = requests.post(
    "https://remover.dev/v1.0/removebg",
    headers={"X-Api-Key": os.environ["REMOVER_API_KEY"]},
    files={"image_file": open("image.png", "rb")},
    data={"size": "auto"},
)
response.raise_for_status()
open("no-bg.png", "wb").write(response.content)

connection = RemoveBg::HttpConnection.build("https://remover.dev")
client = RemoveBg::ApiClient.new(connection: connection)
client.remove_from_file(
  "image.png",
  RemoveBg::RequestOptions.new(api_key: ENV["REMOVER_API_KEY"], size: "auto")
).save("no-bg.png")

$request = curl_init("https://remover.dev/v1.0/removebg");
curl_setopt_array($request, [
  CURLOPT_POST => true,
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_HTTPHEADER => ["X-Api-Key: " . getenv("REMOVER_API_KEY")],
  CURLOPT_POSTFIELDS => ["image_file" => new CURLFile("image.png"), "size" => "auto"],
]);
file_put_contents("no-bg.png", curl_exec($request));

// The official remove.bg plugin always calls api.remove.bg.
// If your own plugin or theme posts the image, this is the endpoint:
$endpoint = "https://remover.dev/v1.0/removebg";
$request = wp_remote_post($endpoint, [
  "headers" => ["X-Api-Key" => getenv("REMOVER_API_KEY")],
  "body" => ["image_url" => $product_image_url, "size" => "auto"],
]);

# The remove.bg Shopify app cannot point at another host.
# Call the HTTP API from a custom app with the same POST body.
curl -H "X-Api-Key: $REMOVER_API_KEY" \
  -F "image_url=$PRODUCT_IMAGE_URL" \
  -F "size=auto" \
  -o no-bg.png \
  https://remover.dev/v1.0/removebg