# Sustainability Subsidy API

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## Introduction

The Subsidy API gives developers programmatic access to Dutch sustainability funding data. It aggregates subsidies and loans from national, provincial, and municipal sources into a single endpoint, and adds calculation logic on top so you can return eligibility and cost estimates directly in your application.

Use the API to:

* **Retrieve current subsidy** and **loan programs** from official Dutch government sources.
* **Check eligibility** against applicant inputs such as income, home ownership, and project type.
* **Calculate loan options**, including interest, total cost, and monthly installments based on duration and repayment period.
* **Estimate the ISDE subsidy amount** (Investeringssubsidie duurzame energie) for a given applicant and project.

Typical integrations include mortgage advisor platforms, energy label tools, and home improvement calculators that need to surface funding options at the point of decision


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