reth/examples/full-contract-state/README.md

Full Contract State Example

This example demonstrates how to extract the complete state of a specific contract from the reth database.

What it does

The example shows how to:

1. Connect to a reth database - Uses the recommended builder pattern to create a read-only provider
2. Get basic account information - Retrieves balance, nonce, and code hash for the contract address
3. Get contract bytecode - Fetches the actual contract bytecode if the account is a contract
4. Iterate through all storage slots - Uses database cursors to efficiently retrieve all storage key-value pairs

Prerequisites

• A reth database with some data (you can sync a node or use a pre-synced database)
• Set the RETH_DATADIR environment variable to point to your reth data directory
• Set the CONTRACT_ADDRESS environment variable to provide target contract address

Usage

# Set your reth data directory
export RETH_DATADIR="/path/to/your/reth/datadir"
# Set target contract address
export CONTRACT_ADDRESS="0x0..."

# Run the example
cargo run --example full-contract-state

Code Structure

The example consists of:

• ContractState struct - Holds all contract state information
• extract_contract_state function - Main function that extracts contract state
• main function - Sets up the provider and demonstrates usage

Key Concepts

Provider Pattern

The example uses reth's provider pattern:

• ProviderFactory - Creates database connections
• DatabaseProvider - Provides low-level database access
• StateProvider - Provides high-level state access

Database Cursors

For efficient storage iteration, the example uses database cursors:

• cursor_dup_read - Creates a cursor for duplicate key tables
• seek_exact - Positions cursor at specific key
• next_dup - Iterates through duplicate entries

Output

The example will print:

• Contract address
• Account balance
• Account nonce
• Code hash
• Number of storage slots
• All storage key-value pairs

Error Handling

The example includes proper error handling:

• Returns None if the contract doesn't exist
• Uses ProviderResult for database operation errors
• Gracefully handles missing bytecode or storage