# Smart Contracts

## CommitmentsInbox 

**What it does:** The CommitmentsInbox contract receives and processes block headers and other data sent from Layer 1 to Layer 2. It verifies the authenticity of the data using signatures and stores it for further processing. \
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**Relevance:** This contract is crucial for ensuring secure and reliable data transfer from Layer 1 to Layer 2, maintaining data integrity in cross-chain operations.

## FactsRegistry 

**What it does:** The FactsRegistry contract stores and manages verified blockchain data, such as account balances, storage values, and block headers. It provides functions to prove and access this data on-chain. 

**Relevance:** This contract is the core of the Storage Proofs system, allowing smart contracts to access and verify data from other chains or historical states trustlessly.

## HeadersStore 

**What it does:** The HeadersStore contract manages a Merkle Mountain Range (MMR) of block headers. It allows for efficient storage and verification of a large number of block headers. 

**Relevance:** This contract enables efficient historical data access and verification, which is essential for cross-chain and historical data proofs.

## TimestampRemapper 

**What it does:** The TimestampRemapper contract maintains a mapping between timestamps and block numbers. It allows for efficient querying of block numbers by timestamp. 

**Relevance:** This contract is important for time-based queries and proofs, allowing users to reference data by time rather than block number.

## AggregatorsFactory 

**What it does:** The AggregatorsFactory contract creates and manages instances of SharpFactsAggregator contracts. These aggregators are responsible for accumulating and verifying proofs from the Starkware SHARP. 

**Relevance:** This contract is crucial for the scalability and efficiency of the Storage Proofs system, allowing for batched verification of multiple proofs.

## SharpFactsAggregator 

**What it does:** The SharpFactsAggregator contract receives and verifies batches of proofs from the SHARP system. It updates the state of the HeadersStore and FactsRegistry based on these verified proofs. 

**Relevance:** This contract is key to the efficient and secure updating of the Storage Proofs system state, bridging the off-chain proof generation with on-chain state updates.

## HeadersProcessor 

**What it does:** The HeadersProcessor contract verifies and processes block headers. It checks the validity of block headers and their relationship to previously processed headers. 

**Relevance:** This contract ensures the integrity and continuity of the block header chain, which is fundamental to the security of the Storage Proofs system.

## L1MessagesProxy 

**What it does:** The L1MessagesProxy contract acts as a proxy for sending messages from Layer 2 to Layer 1. It aggregates messages and handles the cross-chain communication protocol. 

**Relevance:** This contract is essential for enabling Layer 2 to Layer 1 communication, allowing for data and state updates to be propagated back to the main chain.

These contracts work together to create a secure, efficient, and flexible system for proving and accessing blockchain data across different chains and historical states. The system leverages zero-knowledge proofs and efficient data structures to minimize on-chain computation and storage while maintaining high security guarantees.