> ## Documentation Index > Fetch the complete documentation index at: https://docs.celo.org/llms.txt > Use this file to discover all available pages before exploring further. # Fee abstraction guide > Pay gas fees in ERC20 tokens instead of CELO, how the protocol charges them, and which wallets build the CIP-64 transaction that makes it work This page is the guide to fee abstraction for app and agent developers. To send a transaction, see [Using fee abstraction](/build/fee-abstraction/using-fee-abstraction). For token and adapter addresses, see [Fee currency contracts](/build/tools/contracts/fee-currencies). For the protocol rules (exchange rates, tx-pool checks, intrinsic gas, node flags), see the [fee abstraction specification](/operate/specification/fee-abstraction). Fee abstraction is one of Celo's core protocol features. It allows users to pay gas fees in ERC20 tokens — like USDC, USDT, or Mento stablecoins — instead of needing to hold the native CELO token. ## Why Fee Abstraction Matters On most EVM chains, users must hold the native token to pay for gas. This creates friction: a user who receives USDC on Celo can't send it anywhere without first acquiring CELO. Fee abstraction removes this barrier entirely. With fee abstraction, a user holding only USDC can send transactions, interact with contracts, and pay gas — all in USDC. No bridging, no swaps, no extra steps. This is especially valuable for: * **Onboarding new users** who receive stablecoins but don't know about gas tokens * **Payment applications** where users transact in a single currency end-to-end * **AI agents** that operate autonomously with a single token balance ## How It Works Fee abstraction is built into the Celo protocol at the node level — it is not a paymaster or relayer. When a transaction includes a `feeCurrency` field, the Celo blockchain: 1. Calls `debitGasFees` on the fee currency contract to reserve the maximum gas cost 2. Executes the transaction normally 3. Calls `creditGasFees` to refund unused gas and distribute fees to block producers This means fee abstraction works with any externally owned account (EOA) at the protocol level. No smart contract wallets, no relayers, no extra infrastructure needed. To use an alternate fee currency, set its token or adapter address as the `feeCurrency` property on the transaction object. For implementation details, see [Using Fee Abstraction](/build/fee-abstraction/using-fee-abstraction). To add a new fee currency to the protocol, see [Adding Fee Currencies](/build/fee-abstraction/add-fee-currency). ## Wallet support for CIP-64 The protocol accepts a `feeCurrency` transaction from any account, but something has to build that transaction. `feeCurrency` is a field on the [CIP-64](https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0064.md) transaction type, so the wallet signing it must implement CIP-64. Setting `feeCurrency` in your app is necessary but not sufficient: whether it takes effect is decided by the wallet your user brings. A wallet without CIP-64 support does not honour `feeCurrency`, and nothing tells you so. Some wallets, MetaMask among them, drop the field and sign a standard transaction: gas then comes out of the user's CELO balance, or, if the user holds no CELO, the transaction fails with a generic insufficient-funds error. A wallet that validates request parameters may instead reject the request outright. None of these outcomes points at the wallet as the cause. | Wallet | How `feeCurrency` is handled | | - | - | | [MiniPay](/build/mini-apps/overview) | Pays gas in the stablecoin the user holds the most of, and [may override](/build/mini-apps/overview#gas-is-paid-in-stablecoins) a `feeCurrency` you set | | [Valora](https://valora.xyz/) | Builds CIP-64 itself and ignores a `feeCurrency` you set. It re-selects, paying in CELO when the balance covers the fee and otherwise in the fee currency the user holds the most of by value. See the [wallet source](https://github.com/valora-xyz/wallet-stack/blob/df76b6befdc50b94a19646234d7128d67159d1cd/packages/wallet-stack/src/walletConnect/saga.ts) | | [Ledger Live](/build/tools/wallets/ledger/setup) | Ledger Live's own send flow builds CIP-64 and lets the user choose the fee currency, on Ledger Live 4.8 or later. This does not extend to apps: a Ledger used through MetaMask signs what MetaMask builds, and MetaMask drops `feeCurrency` | | [MetaMask](/build/tools/wallets/metamask/setup) | Not supported. The [transaction controller](https://github.com/MetaMask/core/blob/418d6759bdde9cdf450444a8db66d41b78f8128c/packages/transaction-controller/src/utils/utils.ts) keeps only the fields it knows, so `feeCurrency` is dropped and gas is charged in CELO | A wallet not listed here has not been confirmed either way. Check with the wallet before assuming. If a flow depends on fee abstraction, such as onboarding a user who holds no CELO, either target a wallet on this list or keep a path that works when gas is charged in CELO. Library support is a separate question from wallet support, and a library in a wallet's stack says nothing about whether that wallet forwards an app's `feeCurrency`. For viem, Ethers.js and web3.js, see [Using Fee Abstraction](/build/fee-abstraction/using-fee-abstraction#using-fee-abstraction-with-viem). ## Fee currencies and adapters The allowlist, with token and adapter addresses for each network, is on [Fee currency contracts](/build/tools/contracts/fee-currencies). Tokens with 6 decimals (USDC, USDT, USA₮) go through an adapter, and the adapter address, not the token address, is the `feeCurrency` value; see [adapters for non-18-decimal tokens](/build/fee-abstraction/using-fee-abstraction#adapters-for-non-18-decimal-tokens). *** ## Related * [Fee currency contracts](/build/tools/contracts/fee-currencies) — Allowlisted tokens with their `feeCurrency` and token addresses * [Fee abstraction specification](/operate/specification/fee-abstraction) — Protocol rules, JSON-RPC changes and node flags * [Fee Abstraction for AI Agents](/build/agents/overview#fee-abstraction-for-agents) — Using fee abstraction in autonomous agent backends * [x402: Agent Payments](/build/agents/x402) — HTTP-native stablecoin payments for agents * [Using Fee Abstraction](/build/fee-abstraction/using-fee-abstraction) — How to pay gas with alternate fee currencies in your transactions * [Adding Fee Currencies](/build/fee-abstraction/add-fee-currency) — How to implement and register a new fee currency * [Wallets for users](/learn/wallets) — Wallets a holder can install, including the ones in the table above * [Wallet integration](/build/tools/wallets) — Providers an app can integrate to add wallets This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.