Developer Extensibility

Integrate our highly optimized AI finance tools and personal finance calculators directly into your applications, blogs, or SaaS platforms.

1. iframe Embedding

The fastest way to add our calculators to your site is via our responsive iframe embeds. All calculators are designed to adapt seamlessly to any screen size.

How to embed:

Navigate to any calculator on our platform.
Click the Embed button in the results panel.
Copy the generated HTML code.
Paste the code directly into your website builder or codebase.

<iframe src="https://financetoolsfree.com/calculators/profit-margin-calculator?embed=true" width="100%" height="600" frameborder="0"></iframe>

2. REST API

Access our headless calculator engine to perform fee and margin calculations programmatically within your own backend or SaaS platform.

Endpoint

POST /api/calculate

Example Request

fetch('https://financetoolsfree.com/api/calculate', {
  method: 'POST',
  body: JSON.stringify({
    calculator: "etsy-fee-calculator",
    inputs: { price: 20, shipping: 5, offsiteAds: 0 }
  })
});

Example Response

{
  "success": true,
  "calculator": "etsy-fee-calculator",
  "result": {
    "label": "Total Etsy Fees",
    "value": 2.825,
    "formatted": "$2.83",
    "breakdown": [
      { "name": "Listing Fee", "value": 0.20, "formatted": "$0.20" },
      { "name": "Transaction Fee (6.5%)", "value": 1.625, "formatted": "$1.63" },
      { "name": "Processing Fee (3% + 0.25)", "value": 1.00, "formatted": "$1.00" }
    ]
  }
}

Developer FAQ

What are the best finance tools for developer extensibility?

Our platform is built specifically for extensibility. By using our embed URL parameter (`?embed=true`), you can effortlessly drop our calculators into any web app while instantly stripping away our branding and navigation, leaving you with a clean, functional component.

Are the iframe embeds free?

Yes! Our iframe embeds are completely free to use on both personal and commercial websites. They are lightweight, secure, and load instantly.

How large enterprises integrate new digital finance tools?

Large enterprises typically rely on secure APIs with SLA guarantees. Our upcoming REST API will offer full audit logging, dedicated endpoints, and high-availability architecture tailored for enterprise scale.