# CAIP Standards

## Overview

Vilna API implements Chain Agnostic Improvement Proposals (CAIP) for consistent cross-chain identification. These standards provide a universal way to identify blockchains, accounts, and assets across different blockchain ecosystems.

## CAIP-2: Blockchain Identification

Provides a way to identify any blockchain in a human-readable, developer-friendly format.

### Format


```
<namespace>:<reference>
```

### Components

- **namespace**: Identifies the blockchain namespace (e.g., `eip155` for EVM chains, `bip122` for Bitcoin)
- **reference**: Chain-specific identifier (chain ID for EVM, genesis block hash for Bitcoin)


### Examples

#### EVM Chains

- `eip155:1` - Ethereum Mainnet
- `eip155:56` - BNB Smart Chain (BSC)
- `eip155:137` - Polygon
- `eip155:43114` - Avalanche C-Chain
- `eip155:42161` - Arbitrum One
- `eip155:10` - Optimism


#### Non-EVM Chains

- `bip122:000000000019d6689c085ae165831e93` - Bitcoin Mainnet
- `bip122:00000000001a91e3dace36e2be3bf030` - Dogecoin
- `cosmos:cosmoshub-4` - Cosmos Hub
- `solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp` - Solana Mainnet


## CAIP-10: Account Identification

Identifies blockchain accounts across different chains with a unified format.

### Format


```
<blockchain_gid>:<account_address>
```

### Components

- **blockchain_gid**: CAIP-2 blockchain identifier
- **account_address**: Chain-specific address format


### Examples

#### Ethereum Accounts


```
eip155:1:0x742d35Cc6634C0532925a3b844Bc9e7595f7B123
```

#### Bitcoin Accounts


```
bip122:000000000019d6689c085ae165831e93:1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa
```

#### Solana Accounts


```
solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp:9WzDXwBbmkg8ZTbNMqUxvQRAyrZzDsGYdLVL9zYtAWWM
```

## CAIP-19: Asset Identification

Provides a universal way to identify any digital asset on any blockchain.

### Format


```
<blockchain_gid>/<asset_namespace>:<asset_reference>
```

### Components

- **blockchain_gid**: CAIP-2 blockchain identifier
- **asset_namespace**: Type of asset (`slip44` for native, `erc20`/`erc721` for tokens)
- **asset_reference**: Asset-specific identifier


### Asset Types

#### Native Currencies

Use `slip44` namespace with the coin type from SLIP-44 registry:


```
<blockchain_gid>/slip44:<coin_type>
```

**Examples:**

- `eip155:1/slip44:60` - ETH on Ethereum
- `eip155:56/slip44:60` - BNB on BSC
- `eip155:137/slip44:60` - MATIC on Polygon
- `bip122:000000000019d6689c085ae165831e93/slip44:0` - BTC on Bitcoin


#### ERC-20 Tokens

Use `erc20` namespace with the contract address:


```
<blockchain_gid>/erc20:<contract_address>
```

**Examples:**

- `eip155:1/erc20:0xdAC17F958D2ee523a2206206994597C13D831ec7` - USDT on Ethereum
- `eip155:1/erc20:0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48` - USDC on Ethereum
- `eip155:56/erc20:0x55d398326f99059fF775485246999027B3197955` - USDT on BSC


#### NFTs (ERC-721)

Use `erc721` namespace with the contract address and token ID:


```
<blockchain_gid>/erc721:<contract_address>/<token_id>
```

**Example:**

- `eip155:1/erc721:0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13D/101` - BAYC #101


## Transaction GID (Vilna Extension)

Vilna extends CAIP standards to provide transaction identification.

### Format


```
<blockchain_gid>:<transaction_hash>
```

### Components

- **blockchain_gid**: CAIP-2 blockchain identifier
- **transaction_hash**: Native transaction hash


### Examples

- `eip155:1:0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef` - Ethereum transaction
- `eip155:56:0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890` - BSC transaction
- `solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp:3Ux7YJz3Fqx8hKzJH...` - Solana transaction


## Benefits

1. **Universal Identification**: One format works across all blockchains
2. **No Ambiguity**: Each identifier is globally unique
3. **Human Readable**: Easy to understand and debug
4. **Tool Agnostic**: Works with any blockchain tool or service
5. **Future Proof**: Extensible for new blockchains and asset types


## References

- [CAIP-2 Specification](https://github.com/ChainAgnostic/CAIPs/blob/master/CAIPs/caip-2.md)
- [CAIP-10 Specification](https://github.com/ChainAgnostic/CAIPs/blob/master/CAIPs/caip-10.md)
- [CAIP-19 Specification](https://github.com/ChainAgnostic/CAIPs/blob/master/CAIPs/caip-19.md)
- [SLIP-44 Registry](https://github.com/satoshilabs/slips/blob/master/slip-0044.md)


*CAIP standards ensure consistent asset identification across all supported blockchains.*