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

# Specifications

> This directory contains specifications for the modules of the Cosmos SDK as well as Interchain Standards (ICS) and other specifications.

This directory contains specifications for the modules of the Cosmos SDK as well as Interchain Standards (ICS) and other specifications.

Cosmos SDK applications hold this state in a Merkle store. Updates to
the store may be made during transactions and at the beginning and end of every
block.

## Cosmos SDK specifications

* [Store](/sdk/v0.50/learn/advanced/store) - The core Merkle store that holds the state.
* [Bech32](/sdk/v0.50/build/spec/addresses/bech32) - Address format for Cosmos SDK applications.

## Modules specifications

Go the [module directory](/sdk/latest/modules/modules)

## CometBFT

For details on the underlying blockchain and p2p protocols, see
the [CometBFT specification](https://github.com/cometbft/cometbft/tree/main/spec).