# Neo N3 Constants and Reference Data
This module provides essential constants and reference data for working with the Neo N3 blockchain.
## Native Contracts
The `native_contracts` module provides script hash constants for all native contracts built into the Neo N3 blockchain.
```rust
use neo3::constants::native_contracts::{NEO_TOKEN, GAS_TOKEN};
// Use the native contract script hashes directly
println!("NEO Token: {}", NEO_TOKEN);
println!("GAS Token: {}", GAS_TOKEN);
```
## Famous Contracts
To access information about well-known contracts deployed on Neo N3 mainnet and testnet, use the `neo_contract::famous::contracts` module:
```rust
use neo3::neo_contract::famous::contracts::{get_famous_contracts, Network};
// Get all mainnet contracts
let mainnet_contracts = get_famous_contracts(Network::Mainnet);
// Get information about Flamingo Finance
let flamingo = flamingo_flamingo_finance();
println!("Flamingo Finance contract: {}", flamingo.script_hash);
```
## NeoFS Endpoints
The NeoFS client provides constants for standard endpoints:
```rust
use neo3::neo_fs::client::{
DEFAULT_MAINNET_ENDPOINT,
DEFAULT_TESTNET_ENDPOINT,
DEFAULT_MAINNET_HTTP_GATEWAY,
DEFAULT_TESTNET_HTTP_GATEWAY,
DEFAULT_MAINNET_REST_API,
DEFAULT_TESTNET_REST_API,
};
// Use in NeoFS client configuration
let config = NeoFSConfig {
endpoint: DEFAULT_MAINNET_REST_API.to_string(),
// ...other config options
};
```
## Reference Data
For a comprehensive list of network endpoints, contracts, and other reference data, see the [`src/neo_fs/reference_data.md`](../neo_fs/reference_data.md) file.
This file contains:
- Native contract addresses
- Famous contract addresses
- RPC endpoints for mainnet and testnet
- NeoFS endpoints
- Block explorer URLs
- Additional resources