Quick start

Prerequisites

An IOTools.cloud account — free, and enough to use the API
An API key

There is no paid plan to buy first. Any signed-in member can mint a key and call all 800+ API-enabled tools. The Builder plan raises your monthly credits and rate limit; it does not unlock endpoints.

Create an API key

Go to Account → API keys and create one.

The key is shown once, at creation. Store it before closing the dialog — you can always revoke it and mint another.

Find the tool you want

Any tool page with an API tells you its endpoint: open the tool, click Builder → REST API, and copy the request.Or list them all:

curl https://api.iotools.cloud/v1/tools/list \
  -H "Authorization: Bearer YOUR_API_KEY"

An endpoint is the tool’s slug: https://iotools.cloud/tool/case-converter/ is POST /v1/tool/case-converter.

Make the call

The body is the tool’s fields, at the top level — there is no inputs wrapper. Field names always start with io, and GET /v1/tool/{slug} lists them with their types and defaults.

cURL
Node.js
Python

curl -X POST https://api.iotools.cloud/v1/tool/case-converter \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "ioInputString": "hello world", "ioCase": "uppercase" }'

const res = await fetch("https://api.iotools.cloud/v1/tool/case-converter", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.IOTOOLS_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ ioInputString: "hello world", ioCase: "uppercase" }),
});

const data = await res.json();
console.log(data.outputs.ioOutputString); // HELLO WORLD

import os, requests

res = requests.post(
    "https://api.iotools.cloud/v1/tool/case-converter",
    headers={"Authorization": f"Bearer {os.environ['IOTOOLS_API_KEY']}"},
    json={"ioInputString": "hello world", "ioCase": "uppercase"},
)

print(res.json()["outputs"]["ioOutputString"])  # HELLO WORLD

Read the response

{
  "request_id": "e4042b29-…",
  "tool": "case-converter",
  "tool_version": "1",
  "outputs": { "ioOutputString": "HELLO WORLD" },
  "credits_used": 1,
  "credits_remaining": 999
}

credits_remaining saves a second call to check your balance. Quote request_id in any support request — it is on the response, the x-request-id header and our logs.

Tools with no required inputs can be called with no body at all — curl -X POST <url> -H "Authorization: Bearer …" runs them on their defaults.

Credits

What each call costs, and when it doesn’t

Errors

The codes to branch on

IOTools.cloud API Authentication

Getting started

Concepts

MCP

Examples

Prerequisites

What to read next

Credits

Errors

​Prerequisites

​What to read next

Credits

Errors

Prerequisites

What to read next