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generateErc3448(implementation: Uint8Array, metadata: Uint8Array): Uint8Array

Generates ERC-3448 MetaProxy bytecode with embedded metadata. Extends ERC-1167 minimal proxy by appending metadata after the proxy code, enabling factory patterns with embedded configuration. Parameters:
  • implementation: Uint8Array - 20-byte implementation address
  • metadata: Uint8Array - Metadata to embed (arbitrary length)
Returns: Uint8Array - Complete MetaProxy bytecode (55 + metadata.length + 32 bytes) Throws:
  • Error - If implementation address is not 20 bytes
Example: 
import { generateErc3448 } from '@tevm/voltaire/Proxy';
import { Address } from '@tevm/voltaire/Address';

// Prepare metadata
const metadata = new TextEncoder().encode(JSON.stringify({
  creator: '0xCreatorAddress...',
  salt: '0x1234...',
  version: 1,
  timestamp: Date.now()
}));

// Generate MetaProxy bytecode
const implementation = Address.from('0x1234567890123456789012345678901234567890');
const bytecode = generateErc3448(implementation, metadata);

console.log('Bytecode size:', bytecode.length);
// 55 (ERC-1167) + metadata.length + 32 (length) bytes
Defined in: src/primitives/Proxy/generateErc3448.js

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Factory Pattern with Metadata

import { generateErc3448 } from '@tevm/voltaire/Proxy';
import { Address } from '@tevm/voltaire/Address';
import { keccak256 } from '@tevm/voltaire/crypto';

class MetaProxyFactory {
  async createProxy(
    implementation: string,
    config: {
      creator: string;
      salt: string;
      chainId: number;
    }
  ) {
    // Encode configuration as metadata
    const metadata = new TextEncoder().encode(
      JSON.stringify(config)
    );

    // Generate bytecode
    const bytecode = generateErc3448(
      Address.from(implementation),
      metadata
    );

    // Calculate CREATE2 address
    const factoryAddress = Address.from(this.address);
    const saltBytes = keccak256(
      new TextEncoder().encode(config.salt)
    );
    const proxyAddress = Address.calculateCreate2Address(
      factoryAddress,
      saltBytes,
      bytecode
    );

    return {
      bytecode,
      address: proxyAddress.toHex(),
      metadata: config
    };
  }
}

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See Also