> ## 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.

# Fees Engine in Lerian Console

> Explore the Fees Engine in the Midaz Module: enable it, manage Fee Packages, and estimate charges from the Console using Ledgers, segments, and routes.

The **Fees Engine** is an optional capability of the Midaz Module that lets operators model transaction fees from the Console. Once enabled, it adds two pages to the Midaz Module sidebar:

* **Fee Packages**: create and edit packages and their rules.
* **Calculator**: estimate what a package would charge before you apply it to a real Transaction.

The Fees Engine builds on the same Ledgers, Segments, Transaction Routes, and Accounts already defined in Midaz Core.

Packages use that existing structure to set their scope. Midaz applies a package automatically to each Transaction that matches its conditions.

## Key concepts

***

* **Fee Package** — Container that groups one or more fee rules and the conditions under which they apply (transaction route, segment, ledger, amount range).
* **Fee Rule** — An individual fee inside a package, with its own calculation method.
* **Application Rule** — How Midaz calculates a single fee: **flat**, **percentage**, or **maximum between both**.
* **Reference Amount** — Whether a percentage fee applies to the original Transaction amount or to the amount after other fees.
* **Priority** — The order in which Midaz applies multiple fees inside the same package.
* **Waiver** — A source account exempted from a given package.

## Enabling the Fees Engine

***

The Fees Engine appears in the sidebar only after you enable it. The [Plugin settings](/en/platform/console/plugin-settings) page shows different options for each organization license. If you do not see the Fees Engine there, contact the Lerian team.

<Steps>
  <Step title="Open Plugin settings">
    From the Midaz Module sidebar, go to **Settings** > **Plugins**.
  </Step>

  <Step title="Enable Fees Engine">
    Toggle **Fees Engine** on. The **Fees Engine** menu item appears in the sidebar with **Fee Packages** and **Calculator** sub-items.
  </Step>
</Steps>

<Note>
  If you disable the Fees Engine later, Midaz hides its menu but keeps every Fee Package you created.
</Note>

## Where to go next

***

<Columns cols={2}>
  <Card title="Manage Fee Packages" icon="box" horizontal href="/en/midaz/fees/console/managing-fee-packages">
    Create, edit, and delete packages — define rules, scope by ledger or segment, and set waivers.
  </Card>

  <Card title="Fee Calculator" icon="calculator" horizontal href="/en/midaz/fees/console/managing-fee-calculations">
    Estimate what a package would charge for a sample Transaction without running a real one.
  </Card>

  <Card title="Billing Runs" icon="receipt" horizontal href="/en/midaz/fees/console/billing-runs">
    Preview the fees for a period before you apply them.
  </Card>
</Columns>