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Solayer Bridge (sBridge) is a canonical, SVM-native cross-chain bridge purpose-built to connect Solana and Solayer with high throughput, deterministic security, and composable execution. It offers an execution-native bridge architecture, replacing generalized, exploit-prone multichain bridges with a protocol aligned tightly to the Solana Virtual Machine (SVM).

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What is sBridge?

sBridge is tailored specifically to SVM environments, differing significantly from generic multichain solutions such as Wormhole, LayerZero, and Hyperlane by offering tighter semantic integration, higher capital efficiency, and protocol-level control.

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Overview

sBridge enables:
  • Asset transfer and wrapped token minting between Solana and Solayer
  • Cross-chain call execution, such as swapping on Solayer and depositing LP on Solana in a single transaction
  • Sub-3s optimistic finality for low-value txs, and deterministic finality for high-value txs
  • Hardware-backed ED25519 multi-signatures using guardian quorum
  • Double-handling prevention using Program Derived Addresses (PDAs)
  • Permissionless token bridging - Bridge ANY token without whitelisting
  • Bidirectional bridge between Solayer and Solana with secure and preauthorized cross-chain communication
Unlike other bridges, sBridge is designed from the ground up to support SVM-to-SVM communication. It embraces SVM-specific architecture such as return-data handling, PDA proofs, and polling-based transaction indexing for reliability and performance.

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Why We Built sBridge

We chose to develop sBridge in-house because existing bridging solutions lacked critical features needed for our specific domain, such as enhanced flexibility, strict latency guarantees, and deeper protocol-level control. By integrating on-chain duplicate prevention, poll-based transaction subscription, guardian auto-failover mechanism, and a dynamic-finality model (fast optimistic + slow finalized), we ensure low-latency and highly available bridging without compromising security. Unlike other bridges, we also have a fully database-less implementation for sBridge. By maximizing the PDA of SVM, we manage to not store anything locally, even for indexing bridge transactions purpose. This helps reduce security back possibilities and opens for more development opportunities on top of it. The unique cross-chain call functionality also unlocks new capabilities in interchain operability, enabling atomic transactions across multiple chains in a single bundled operation. The architecture is also designed with future extensibility in mind, supporting dynamic validator sets, additional message types, and programmable token minting.

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Key Features

  • Secure Asset Transfers: Ensure asset safety across different SVM chains
  • Cross-chain Execution: Support for atomic transactions and seamless multi-chain interactions
  • Guardian Network: Decentralized validation through threshold signature aggregation
  • No-database Design: By maximizing SVM PDA, the system does not have any centralized database involved at any point

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Architecture: 3-Layer Bridge

sBridge consists of three layers:
  1. Origin Chain – User invokes bridgeAsset or crossChainCall, creating a unique PDA as a proof-of-intent.
  2. Guardian Network (Off-Chain) – Guardians poll transactions via RPC, validate signatures, and submit a threshold-signed proof.
  3. Destination Chain – Bridge program verifies multi-sig via Solana’s precompile and executes the asset transfer or cross-chain instruction.
User → [Origin Chain (PDA + Bridge Program)] → [Guardian Network] → [Destination Chain (PDA Check + Execution)]

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On-chain Program

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Asset Bridge

  • bridgeAssetSourceChain: Initiated on Solana (or origin chain). Tokens are deducted, a fee is extracted, and a bridge vault locks the asset. A PDA is generated based on (sender, recipient, mint, amount, nonce, txId).
  • bridgeAssetTargetChain: Invoked on Solayer (or destination chain). After guardian multi-sig is verified, tokens are released or wrapped tokens minted.

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Cross-Chain Call

Users can sign serialized transactions (e.g., Solana LP deposit) on Solayer and dispatch it cross-chain. The leader guardian decodes and simulates the payload, then executes it directly. 
await bridgeClient.crossChainCall({
  serializedTx: serializedCrossChainTransaction,
});
This enables multi-leg transactions like:
  • Solayer swap → Solana LP deposit → All in one signed tx

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Off-chain Guardian Network

  • Leader–Follower Model: Guardians gossip signed payloads. A rotating leader aggregates multi-sigs and submits to destination chain.
  • Poll-based indexing: No reliance on fragile WebSocket subscriptions. Guardians poll RPC endpoints for new bridge transactions.
  • ED25519 multi-sig: All signatures are generated using hardware-backed HSMs and verified via Solana’s precompile.

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Reliability & Failure Recovery

  • Replay protection: All bridge actions generate unique PDAs. Existing PDAs are checked before any execution.
  • Exactly-once semantics: Guardians track high-water marks and nonces to prevent duplicate processing.
  • Leader failover: If a leader becomes unresponsive, a new one is elected via round-robin.

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Dynamic Finality Model

  • Fast-path finality: < $1K txs execute after “confirmed” block state, finalizing in ~3s
  • Slow-path finality: High-value txs wait for irreversible finality on source chain
  • Misbehavior by guardians (e.g., signing before safe finality) can result in slashing or removal

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Performance (Devnet Metrics)

MetricsBridgeAvg. Multichain Bridge
Median Finality (< $1K tx)~3 sec~8 sec
Avg. Fee0.0006 SOL0.0014 SOL
Throughput~1000 tx/s~400 tx/s
This documentation provides a comprehensive guide to understanding and implementing the Solayer Bridge effectively.