Gas Token Portability

Allows users to pay for transaction fees (gas) on a destination chain using a single, familiar asset from a source chain. For example, a user can pay for an Arbitrum transaction using their Ethereum (ETH) balance, eliminating the need to bridge and hold separate Arbitrum ETH for gas.

Removes the operational friction of bridging assets solely for gas. Users no longer need to:

• Manually bridge small amounts of native gas tokens.
• Manage multiple wallet balances across chains.
• Calculate optimal bridging amounts to avoid getting stranded without gas.

Dramatically simplifies the multi-chain experience for end-users and developers. Applications can offer a seamless flow where users interact with a smart contract on any supported chain using the assets they already hold, reducing onboarding steps and potential user error.

Typically implemented via a meta-transaction or paymaster model. A third-party relayer submits the transaction on the user's behalf and pays the native gas fee. The user then compensates the relayer in their preferred token, often via a signed message or a deduction from the transaction's output.

Implemented by cross-chain messaging and interoperability protocols to enable seamless app interactions.

• LayerZero's OApp standard allows developers to implement gas token portability.
• Axelar's General Message Passing (GMP) enables paying destination chain gas with source chain assets.
• Circle's Cross-Chain Transfer Protocol (CCTP) uses relayer networks for gas abstraction.

Reduces capital fragmentation and opportunity cost. Users' capital remains productive on their preferred chain (e.g., in a liquidity pool or staking contract) instead of being locked as idle gas funds on multiple networks. This optimizes overall capital efficiency in a multi-chain ecosystem.

In a multi-chain ecosystem, users must hold the native gas token (e.g., ETH, MATIC, AVAX) of each network they interact with to pay for transactions. This creates fragmented liquidity, poor user experience, and onboarding friction. Gas token portability solves this by allowing a single token to be used across chains.

Portability is typically achieved by bridging the native token to the destination chain, where it becomes a wrapped asset (e.g., WETH on Arbitrum). A gas relayer or paymaster contract on the destination chain then accepts this wrapped token, converts it, and uses it to pay the network's native gas fees on the user's behalf.

A paymaster is a smart contract that can sponsor transaction fees. In portability systems, it:

• Accepts the user's portable gas token (e.g., bridged ETH).
• Swaps it for the chain's native token via a DEX or holds reserves.
• Pays the base fee and priority fee to the block validator. This is a core feature of account abstraction (ERC-4337).

A user can bridge ETH to an Arbitrum or Optimism rollup and use it directly for gas, without needing ARB or OP tokens. Similarly, protocols like Socket enable ETH to be used for gas on chains like Polygon or BNB Chain through unified liquidity layers and intent-based routing.

• User Experience: Seamless cross-chain interactions without managing multiple token balances.
• Security: Reduces exposure to malicious bridges for frequent small transactions.
• Liquidity Efficiency: Concentrates liquidity in primary assets like ETH or stablecoins.
• Developer Adoption: DApps can onboard users from other ecosystems more easily.

• Relayer Trust: Users must trust the paymaster or relayer service.
• Bridge Risk: The initial bridging step still carries smart contract and custodial risks.
• Economic Incentives: Paymasters require sustainable models for token swaps and fee margins.
• Protocol Support: Not all chains or wallets natively support portable gas payment systems.

Portable gas tokens separate the fee market from the staking/security market. This creates a critical dependency: the chain's security (e.g., staked ETH) must be robust enough to protect the value of the portable fee token. A successful 51% attack could undermine the economic value of the portable token, creating a feedback loop of devaluation.

Gas fees become subject to the volatility and liquidity of the external token. If the portable token's price crashes or liquidity dries up, users may be unable to pay for transactions, potentially freezing the chain. This contrasts with native token fee models where fee value and security are inherently aligned.

Validators or miners are paid block rewards in the native staking token but may receive fees in a portable token. This can lead to incentive misalignment if the portable token's value diverges significantly. Protocols must design robust mechanisms (e.g., fee conversion or distribution schedules) to ensure validator economics remain sustainable.

Portability often relies on a bridge or wrapping mechanism (e.g., wETH on a rollup). This introduces smart contract risk and custodial risk if the bridge is centralized. A bridge hack or failure could sever the token's utility for gas, paralyzing the chain. This adds a critical point of failure not present in native gas models.

The chain cedes control over its monetary policy for fees to an external asset's ecosystem. Decisions by the foreign token's governance (e.g., Ethereum's EIPs) directly impact the chain's user costs and economic activity. This creates a form of economic dependency and reduces sovereign control over a core system parameter.

Users must acquire and manage a separate token for fees, adding friction and cognitive overhead. It complicates onboarding and requires understanding multiple asset types. While abstracted wallets can help, the underlying complexity remains a barrier and a potential source of user error (e.g., holding value but no gas).