Threshold Network’s tBTC on Sui: Engineering Bitcoin’s First Fully Live Non-EVM Integration

The launch of tBTC on Sui markеd a major milestone, bringing over $650M tBTC tvl to one of the fastest and most efficient DeFi ecosystems.

This end-to-end integration connects Bitcoin, Threshold Network, Wormhole, and Sui’s Move-based architecture, now fully live with canonical tBTC minting, direct Bitcoin deposits, and redemptions.
The Sui-side implementation, from contract deployment to Wormhole configuration and relayer orchestration was delivered by 4 Point O Labs.

Architecture Overview

The system is composed of three synchronized layers:

1. Threshold Layer – Bitcoin custody and minting
   Threshold’s decentralized 51-of-100 signer network secures BTC deposits and issues proofs that back each minted tBTC 1:1.
   
   
2. Wormhole Layer – cross-chain transport
   Verified Action Approvals (VAAs) from Wormhole guardians transmit deposit and redemption proofs between Ethereum (L1) and Sui.
   
   
3. Sui Layer – canonical tBTC and redemption
   On Sui, Wormhole gateway modules validate VAAs and mint canonical tBTC in Move. Burn events are relayed back to release BTC on the Bitcoin network.
   

This architecture ensures non-custodial BTC management, atomic cross-chain consistency, and sub-second finality on Sui.

Full Integration Overview

The tBTC deployment on Sui brings together three critical components that now operate seamlessly as one system:

• Canonical tBTC on Sui: A Sui-native representation of Bitcoin, fully backed 1:1 by BTC and compatible with Wormhole’s cross-chain framework.
  
  
• Wormhole Gateway: The message relay layer connecting Threshold’s Bitcoin custody network with Sui’s on-chain contracts, enabling secure minting and redemption flows.
  
  
• Direct Bitcoin Deposit Flow: A native deposit pathway that allows users to fund with BTC and receive canonical tBTC directly on Sui — eliminating intermediaries and simplifying user experience.
  

Together, these elements form a complete, non-EVM Bitcoin bridge  enabling BTC to move freely into Sui’s high-performance DeFi environment with full decentralization, liquidity efficiency, and sub-second finality.

Security, Performance & Capital Efficiency

The integration is designed around three core principles:

• Fully non-custodial : BTC secured by Threshold signers, never by a bridge.
  
  
• Trust-minimized : single-use VAAs prevent double-minting or replay.
  
  
• High performance : Sui achieves ~400 ms transaction finality once messages are verified.
  

This results in a secure, decentralized, and capital-efficient flow of Bitcoin liquidity within the Sui ecosystem.

Ecosystem Integration

With tBTC now live on Sui, Bitcoin liquidity is powering a growing number of Sui-native protocols, including Bluefin, AlphaLend, Bucket, AlphaFi, and Ember Protocol. tBTC on Ember Protocol currently has the second-largest vault deposits, sitting at $19 million, and boasting the biggest btc collateral on the platform. All of these protocols utilize the same canonical version of tBTC, ensuring unified and consistent liquidity across the entire network.

Conclusion

The complete rollout of tBTC on Sui establishes a new standard for cross-chain interoperability combining Threshold’s cryptography, Wormhole’s transport, and Sui’s high-throughput Move runtime to deliver true BTCFi at internet speed.

‍