Multi-Sig

Set up threshold and weighted multi-signer flows.

Overview

Smart Account Kit supports multiple signer types and policy-enforced multi-sig authorization. You can require M-of-N passkey signatures, weighted voting, or spending limits - all enforced on-chain by policy contracts.

Adding Multiple Signers

Add additional passkeys to an existing context rule:

// Add a backup passkey to rule 0
await kit.signers.addPasskey(0, 'My App', 'Recovery Key', {
  nickname: 'Backup YubiKey',
});

// Add a G-address signer (hardware wallet, co-signer, etc.)
await kit.signers.addDelegated(0, 'GABC...');

Threshold Policy (M-of-N)

Require M signatures from N signers before authorizing a transaction:

import { createThresholdParams } from 'smart-account-kit';

// 2-of-N threshold
const params = createThresholdParams(2);
const installParams = kit.convertPolicyParams(params);

await kit.policies.add(
  0,                                          // context rule ID
  process.env.THRESHOLD_POLICY_ADDRESS!,
  installParams
);

Weighted Threshold Policy

Assign weights to signers; a transaction requires reaching a total weight threshold:

import { createWeightedThresholdParams } from 'smart-account-kit';

const params = createWeightedThresholdParams(
  100,                     // threshold (total weight required)
  [                        // weights per signer index
    { signerIndex: 0, weight: 70 },
    { signerIndex: 1, weight: 50 },
  ]
);
const installParams = kit.convertPolicyParams(params);

await kit.policies.add(0, process.env.WEIGHTED_THRESHOLD_POLICY_ADDRESS!, installParams);

Executing a Multi-Sig Transaction

Use MultiSignerManager when a transaction requires signatures from multiple signers:

// 1. Discover available signers
const signers = await kit.multiSigners.getAvailableSigners();

// 2. Check if multi-sig is needed
if (!kit.multiSigners.needsMultiSigner(signers)) {
  await kit.transfer(tokenContract, recipient, amount);
  return;
}

// 3. Build signer selection
const selected = kit.multiSigners.buildSelectedSigners(
  signers,
  kit.activeCredentialId
);

// 4. Execute multi-sig transfer
const result = await kit.multiSigners.transfer(
  tokenContract,
  recipient,
  amount,
  selected
);

Spending Limit Policy

Cap token spending over a time window (enforced per-token, per-reset-period):

import { createSpendingLimitParams, LEDGERS_PER_DAY } from 'smart-account-kit';

const params = createSpendingLimitParams(
  'CDLZFC3...',            // token contract (native XLM)
  BigInt(100 * 10_000_000), // 100 XLM in stroops
  LEDGERS_PER_DAY          // resets every ~24 hours
);
const installParams = kit.convertPolicyParams(params);

await kit.policies.add(0, process.env.SPENDING_LIMIT_POLICY_ADDRESS!, installParams);

Time Constants

import { LEDGERS_PER_HOUR, LEDGERS_PER_DAY, LEDGERS_PER_WEEK } from 'smart-account-kit';

LEDGERS_PER_HOUR  // ~720
LEDGERS_PER_DAY   // ~17,280
LEDGERS_PER_WEEK  // ~120,960