--- name: vultisig description: Use this skill when an agent needs to create crypto wallets, send transactions, swap tokens, check balances, or perform any on-chain operation across 36+ blockchains using threshold signatures (TSS). Vultisig SDK provides self-custodial MPC vaults — no seed phrases, no single point of failure. Fast Vaults (2-of-2 with VultiServer) enable fully autonomous agent operations without human approval. user-invocable: true ---

Vultisig SDK Skill (agent-first)

What this Skill is for

• Creating and managing self-custodial crypto vaults (Fast Vault for agents, Secure Vault for multi-device)
• Sending transactions across 36+ blockchains (Bitcoin, Ethereum, Solana, Cosmos, and more)
• Swapping tokens cross-chain via THORChain, MayaChain, 1inch, LiFi, KyberSwap
• Querying balances and gas fees across all supported chains
• Importing/exporting vault backups (.vult files)
• Importing existing wallets via BIP39 seedphrase
• Building automated strategies: DCA, rebalancing, conditional swaps, agent-to-agent payments

Default stack decisions

1) Fast Vault (2-of-2) for all agent use cases - Agent holds one key share, VultiServer holds the other - VultiServer auto-co-signs based on policy rules — no human in the loop - Use Secure Vault only when multi-device human approval is required

2) TypeScript SDK (@vultisig/sdk) as primary interface - npm install @vultisig/sdk - Source: github.com/vultisig/vultisig-sdk - SDK Users Guide: docs/SDK-USERS-GUIDE.md

3) MemoryStorage for ephemeral agents, implement Storage interface for persistent agents - MemoryStorage is the only storage exported from the SDK - For persistent vaults, implement the Storage interface backed by your preferred store

4) 3-step transaction flow: prepare → sign → broadcast - Never skip steps. Always prepare the keysign payload first, then sign, then broadcast. - Fast Vault signing is automatic (VultiServer co-signs). Secure Vault requires device coordination.

5) Amounts as bigint (smallest unit) for sends, number (human-readable) for swaps - prepareSendTx takes amount: bigint (e.g., BigInt('100000000000000000') for 0.1 ETH) - getSwapQuote takes amount: number (e.g., 0.1 for 0.1 ETH)

Operating procedure

1. Initialize SDK

import { Vultisig, MemoryStorage } from '@vultisig/sdk';

const sdk = new Vultisig({ storage: new MemoryStorage() });
await sdk.initialize();

> Source: Vultisig.ts

2. Create a Fast Vault

Two-step process: create (triggers email verification) then verify.

const vaultId = await sdk.createFastVault({
  name: 'my-agent-vault',
  email: '[email protected]',
  password: 'secure-password',
});

// Verify with the code sent to the email
const vault = await sdk.verifyVault(vaultId, '123456');
// Returns: FastVault instance — ready for operations

Risk notes:

• The password encrypts the vault share. If lost, the vault cannot be recovered.
• The email verification code is required — agents must have email access or an email relay.

2b. Create a Secure Vault (human co-signing)

When agents need human approval before executing transactions (high-value transfers, treasury ops, compliance flows), use a Secure Vault. The agent holds one share, the human holds the other. The human co-signs via the Vultisig mobile app by scanning a QR code — the transaction only executes when both parties agree.

const { vault, vaultId, sessionId } = await sdk.createSecureVault({
  name: 'agent-with-human-approval',
  onQRCodeReady: (qrPayload) => {
    // Display QR for the human co-signer to scan with Vultisig app
    displayQRCode(qrPayload);
  },
  onDeviceJoined: (deviceId, total, required) => {
    console.log(`Device joined: ${total}/${required}`);
  },
});

Signing requires the human to participate:

const signature = await vault.sign(payload, {
  onQRCodeReady: (qr) => {
    // Human must scan this QR with Vultisig app to co-sign
    displayQRCode(qr);
  },
  onDeviceJoined: (id, total, required) => {
    console.log(`Signing: ${total}/${required} devices ready`);
  },
});
// Completes only when the human co-signer participates

> Source: SecureVault.ts

When to use Secure Vault over Fast Vault:

• Transactions above a risk threshold that need human sign-off
• Treasury or DAO operations requiring human approval
• Compliance workflows where an agent should not act unilaterally

3. Get addresses

const ethAddress = await vault.address('Ethereum');
const btcAddress = await vault.address('Bitcoin');
const solAddress = await vault.address('Solana');

// All addresses at once
const allAddresses = await vault.addresses();
// Returns: Record<string, string>

> Source: VaultBase.ts

Chain identifiers use PascalCase strings matching the Chain enum: 'Bitcoin', 'Ethereum', 'Solana', 'THORChain', 'Cosmos', 'Polygon', 'Arbitrum', 'Base', 'Optimism', 'Avalanche', 'BSC', etc.

> Full chain list: Chain.ts

4. Check balances

// Native chain balance
const ethBalance = await vault.balance('Ethereum');
// Returns Balance: {
//   amount: string,      // Raw amount in smallest unit
//   decimals: number,    // Chain decimals (18 for ETH)
//   symbol: string,      // "ETH"
//   chainId: string,
//   fiatValue?: number,  // USD value if available
// }

// Multiple chains
const allBalances = await vault.balances();
// Returns: Record<string, Balance>

// Force refresh (clears cache)
const fresh = await vault.updateBalance('Ethereum');

Token balances (ERC-20, SPL, etc.)

// Get a specific token balance by contract address
const usdcBalance = await vault.balance('Ethereum', '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48');
// Returns Balance: { amount: "1000000", decimals: 6, symbol: "USDC", ... }

// Get all token balances on a chain
const ethTokens = await vault.tokenBalances('Ethereum');
// Returns: Token[] — all tokens with non-zero balances

// Include tokens when fetching multi-chain balances
const everything = await vault.balances(undefined, true); // includeTokens = true

Risk notes:

• Native balance and token balances are separate queries. vault.balance('Ethereum') returns only ETH, not ERC-20s.
• Token balances require the contract address as the tokenId parameter.

5. Estimate gas

// Returns chain-specific gas info
const evmGas = await vault.gas('Ethereum');
// EvmGasInfo: { gasPrice, gasPriceGwei, maxFeePerGas, maxPriorityFeePerGas, gasLimit, estimatedCostUSD }

const utxoGas = await vault.gas('Bitcoin');
// UtxoGasInfo: { gasPrice, byteFee, estimatedCostUSD }

const cosmosGas = await vault.gas('Cosmos');
// CosmosGasInfo: { gasPrice, gas, estimatedCostUSD }

> Source: VaultBase.ts — gas(chain: C): Promise>

6. Send a transaction

3-step flow: prepareSendTx → sign → broadcastTx

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