Core Concepts

Transaction lifecycle

Every multisig transaction follows the same lifecycle: propose, sign, execute, sync.

1. Propose: The proposer builds a TransactionSummary locally, signs it, and pushes it to Guardian as a delta proposal.
2. Sign: Each cosigner fetches pending proposals, verifies the transaction details against their local state, and submits their signature.
3. Execute: Once the threshold is met, any participant pushes the final delta (with all signatures). Guardian returns the acknowledged delta. The executor builds and submits the on-chain transaction.
4. Sync: All participants fetch the latest state from Guardian to stay synchronized.

Key architecture: 2-of-3 setup

A common configuration uses a 2-of-3 threshold:

Key	Holder	Purpose
Key 1	User hot key	Daily transactions
Key 2	User cold key	Recovery and emergency override
Key 3	Guardian service key	Co-signing and policy enforcement

• Normal operations: Hot key + Guardian's co-signature are sufficient.
• Emergency override: Hot + cold keys alone can rotate out Guardian or switch providers.
• Guardian alone cannot move funds: It holds only one key in the threshold.

Transaction types

Type	Description
Transfer (P2ID)	Send assets to another account
Consume notes	Spend incoming notes
Add signer	Add a new cosigner to the multisig account
Remove signer	Remove a cosigner
Change threshold	Update the required signature count
Switch Guardian	Change the Guardian provider endpoint

Signer types

The TypeScript SDK supports multiple signer backends:

Signer	Scheme	Use case
FalconSigner	Falcon	Local Falcon key (default)
EcdsaSigner	ECDSA	Local ECDSA key
ParaSigner	ECDSA	External EVM wallets via Para SDK
MidenWalletSigner	Any	Miden Wallet browser extension

Offline fallback

If Guardian is unreachable, the SDKs support fully offline workflows:

1. Create a proposal locally and export it as JSON.
2. Share the file with cosigners through any side channel.
3. Each cosigner signs offline and returns the signed file.
4. Once the threshold is met, execute the transaction on-chain.

This ensures multisig operations remain functional even without Guardian connectivity.