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

# System modules reference

> Bank, distribution, and staking precompile references: method signatures, ABIs, events, and authorization.

Stable exposes core settlement behavior through **System Modules**, implemented as **precompiled contracts** for gas efficiency and predictable control.

<Note>
  **Concept:** For what system modules do and why they're exposed as precompiles, see [System modules](/en/explanation/system-modules-overview).
</Note>

**Key modules:**

* [Bank Module](/en/reference/bank-module-api)
  * Handles USDT transfers, balance accounting, and escrow flows
* [Distribution Module](/en/reference/distribution-module-api)
  * Fee distribution and reward logic for network participants
* [Staking Module](/en/reference/staking-module-api)
  * Controls validator participation and staking (coming with mainnet)

**dApps can leverage built-in modules instead of re-implementing token or settlement logic.**