> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt
> Use this file to discover all available pages before exploring further.

# Fee Engine documentation

> First Fee Engine documentation is now live, with guides on calculations and usage plus the Packages, Calculation, and Estimation API references.

<Badge color="gray" size="lg">April 14th, 2025</Badge> <Badge color="green">Added</Badge>

We’ve just released the first version of the Fee Engine documentation. This plugin helps you calculate and apply fees based on rules you can fully customize.

Here’s what you’ll find in this release:

### Guides

* [**Fee Engine**](/en/midaz/plugins/fees-engine/fee-engine-calculation.mdx): Get a clear understanding of how the plugin works and the problems it solves.
* [**Fee Engine Calculations**](/en/midaz/plugins/fees-engine/fee-engine-calculation.mdx): Explore the calculations behind Fee Engine.
* [**Using Fee Engine**](/en/midaz/plugins/fees-engine/using-fee-engine.mdx): Find out how to use Fee Engine in your projects.

### APIs

* [**Packages API**](/en/reference/midaz/plugins/fees-engine/create-package): Manage your packages with this API.
* [**Calculation API**](/en/reference/midaz/plugins/fees-engine/calculate-fees): Use this API to calculate fees.
* [**Estimation API**](/en/reference/midaz/plugins/fees-engine/simulate-fees): Estimate fees before applying them using this API.
* [**Fee Engine Error List**](/en/reference/midaz/plugins/fees-engine/fee-engine-error-list): List of errors that the plugin can return.