Slipstream

Slipstream is a gasless relayer service that removes one of the biggest friction points in Web3: gas fees. For many users, gas is confusing, inconvenient, and often a blocker for adoption. New users rarely understand why they need to hold tiny amounts of chain-specific tokens, and even experienced users face difficulty when moving across ecosystems. Slipstream solves this by abstracting away gas completely.

With Slipstream, end users can transact without ever worrying about gas tokens, while developers can integrate this functionality into their wallets or decentralized applications with minimal effort. At its core, Slipstream is powered by a relayer system and a developer SDK, which together handle the complexities of gasless transactions behind the scenes.

During ETHGlobal New Delhi, we built a complete product stack:

• The Slipstream Relayer API, which processes transactions through our smart contracts.

• Smart contracts deployed on Arbitrum Sepolia, Base Sepolia (partial), and Kadena Chain Web EVM. These contracts support gasless transactions and are verified and tested.

• An API proxy layer, which ensures that requests to the relayer are validated and secure, preventing misuse.

• A developer-friendly SDK, published on NPM, that allows integration of gasless transactions in just 5–6 lines of code. This is our core deliverable and the part we want developers to adopt first.

Documentation, live and fully in sync with the SDK, making it easy for anyone to get started.

Slipstream currently supports popular tokens including USDC, PyUSD, and other EIP-2612 Tokens like DAI. For Kadena Chain Web, where a USDC token did not exist on testnet, we built and deployed a new USDC contract ourselves so we could enable full gasless support.

By combining these deliverables, Slipstream provides a production-ready foundation for gasless transactions. Developers can focus on building user-friendly experiences, while end users benefit from seamless, frictionless onboarding.

Slipstream was designed and built from scratch in 36 hours at ETHGlobal New Delhi.

We started with the smart contracts. These were written in Solidity and deployed on Arbitrum Sepolia and Kadena Chain Web EVM. To enable gasless functionality, we used two key Ethereum standards: EIP-2612 permits and EIP-712 signatures. These allow users to sign approvals off-chain, which are then relayed on-chain without requiring gas. The contracts were tested, verified, and in Kadena’s case, confirmed against their verification framework.

Next, we built the relayer backend. This is the service that actually submits the signed transactions to the blockchain. To keep it secure, we introduced an API proxy layer. The proxy ensures that third parties cannot directly abuse the relayer. Instead, all requests are validated before being passed along.

On top of that, we built the Slipstream SDK. This SDK is our developer-facing tool and the centerpiece of the project. It is available as an NPM package and designed to be extremely easy to integrate: developers can add gasless transaction support to a wallet or a dApp in just a few lines of code. The SDK is well-documented, and the docs are live right now, in sync with the package’s features.

For integrations, we deployed Slipstream on multiple chains: Arbitrum Sepolia (working), Base Sepolia (partial, deprioritized due to issues), and Kadena Chain Web EVM. We focused on token support for USDC and PyUSD. As a hacky but necessary addition, we deployed our own USDC contract on Kadena’s testnet since one did not exist, enabling full compatibility with Slipstream.

In total, Slipstream combines smart contracts, backend infrastructure, proxy-level security, and a polished SDK. The result is a developer tool that makes gasless transactions a reality across multiple chains, lowering barriers to entry and creating smoother Web3 experiences.