Vault Overview

A Vault is a multi-signature wallet built on Fuel's predicate system. It requires multiple signatures to authorize transactions, providing enhanced security for digital assets.

What is a Vault?

A Vault is a smart contract (predicate) that:

Holds digital assets (tokens, NFTs)
Requires N-of-M signatures to authorize transactions
Supports multiple wallet types (Fuel, EVM, WebAuthn)
Integrates with the Bako Safe ecosystem

Vault Types

The SDK supports two vault configurations:

Type	Enum	Description
BAKO	`ConfigVaultType.BAKO`	Multi-signature vault with multiple signers
CONNECTOR	`ConfigVaultType.CONNECTOR`	Single-signer vault for dApp connections

Key Concepts

Signers

Addresses authorized to sign transactions. A vault can have multiple signers.

const signers = [
  'fuel1address1...',
  'fuel1address2...',
  'fuel1address3...'
];

Threshold (SIGNATURES_COUNT)

Minimum number of signatures required to execute a transaction.

// 2-of-3 multisig: any 2 of 3 signers can approve
const threshold = 2;
const totalSigners = 3;

Predicate Version

The smart contract version used by the vault. Different versions support different features.

const version = '0x6ca3bcd759b944b128e9007e2fa75bf700f28c39ce7b34fc241e2c57bf02bdff';

Vault Class Overview

class Vault extends Predicate {
  // Properties
  readonly bakoFee: number;
  readonly maxSigners: number;
  readonly configurable: VaultConfigurable;
  readonly predicateVersion: string;
 
  // Static methods
  static createBakoVault(provider, config, version?): Vault;
  static createConnectorVault(provider, config, version?): Vault;
  static createFromProvider(provider, version?): Vault;
  static async fromAddress(address, provider): Promise<Vault>;
 
  // Instance methods
  async transaction(params): Promise<TransactionResult>;
  async send(tx): Promise<TransactionResponse>;
  async save(params?): Promise<PredicateResponse>;
  getConfigurable(): VaultConfig;
}

Quick Example

import { BakoProvider, Vault } from 'bakosafe';
 
// Authenticate
const provider = await BakoProvider.create(networkUrl, { apiToken });
 
// Recover existing vault
const vault = await Vault.fromAddress(vaultAddress, provider);
 
// Create transaction
const { tx, hashTxId } = await vault.transaction({
  name: 'Payment',
  assets: [{
    assetId: '0x...',
    amount: '1000000',
    to: 'fuel1recipient...'
  }]
});
 
// Send when signatures are collected
const result = await vault.send(tx);