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

# Module Details

<Info>
  This page will contain detailed information on how a module is installed, uninstalled and the logic behing the deinitialisation data during uninstallation and session-key operations
</Info>

## Module Types

1. Validator
2. Executor
3. Fallback
4. Hook

* Validator, Executor and Fallback modules on the wallet are stored as a circular linked list
* Any installation or uninstallation of module is to link or unlink the module from module store
* Only 1 hook is permitted to be installed for the wallet.

More Details on the Modular contracts can be refered from: [Module-Contracts](https://github.com/etherspot/etherspot-prime-contracts/tree/master/src/modular-etherspot-wallet/modules)

While using module SDK functions, moduleType is mandatory and they are set using the helper constant [MODULE\_TYPE](https://github.com/etherspot/etherspot-modular-sdk/blob/master/src/sdk/common/constants.ts#L26-L31)

If you want to take a look at the SDK code in more detail then you can check these functions out [here on Github](https://github.com/etherspot/etherspot-modular-sdk/blob/master/src/sdk/sdk.ts).