Welcome to sw4p
sw4p enables cross-chain transfers for stablecoins and native tokens. Users sign permits or transactions with their wallet and sw4p handles the underlying cross-chain settlement. Universal gas abstraction: pay gas in the asset being moved. Gasless behavior is supported on eligible paths and should be treated as validated only where the repo documents a real validator rather than an honest SKIP.
Get started in under 5 minutes
npm install @sw4p/sdk
workspace crate: sw4p-sdk
REST API documentation
Vision
Support every blockchain, every stablecoin, and every native token.
The reference integration covers Solana, Base, and Polygon. Current availability must be established from backend readiness; no chain is advertised as payment-ready during maintenance. The broader design includes:
- EVM Chains: Ethereum, Base, Arbitrum, Polygon
- Non-EVM: Solana, Bitcoin discovery surfaces, Tron in gated development
- Tokens: USDC (more coming soon)
Bitcoin is now represented in the shared product and SDK route surfaces as a readiness-gated rail. That means builders can treat BTC as part of the same settlement model while still respecting corridor-specific confirmation time and enablement.
Key Features
Gasless Transfers
Eligible paths can sponsor gas or execution costs, but gasless behavior is only considered validated where the documented validator exists. Unsupported checks should report SKIP, not synthetic success.
Non-Custodial
SDKs never handle private keys. All signing happens in the user's wallet.
Fast
Timing depends on the enabled route, network conditions and verified destination settlement. No universal completion time is guaranteed.
Transparent Fees
Know the exact cost before confirming. Fee estimates include all gas and bridge costs.
How It Works
sequenceDiagram
participant User
participant SDK
participant sw4p API
participant Source Chain
participant Destination Chain
User->>SDK: Sign permit/transaction
SDK->>sw4p API: POST /transfer
sw4p API->>Source Chain: Execute burn
Source Chain-->>sw4p API: Confirm
sw4p API->>Destination Chain: Execute mint
Destination Chain-->>User: Receive tokens