> ## Documentation Index
> Fetch the complete documentation index at: https://docs.biconomy.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Gasless Transactions on EVM: How They Work

> Learn how gasless transactions work on EVM chains. Understand meta-transactions, paymasters, and gas sponsorship for building frictionless Web3 applications

# Gasless Transactions on EVM: How They Work

<Info>
  Biconomy provides gasless transaction capabilities through **MEE (Modular Execution Environment)**. MEE implements all the functionality of ERC-4337 bundlers and paymasters, plus cross-chain orchestration, in a unified developer experience.
</Info>

<Accordion title="What are gasless transactions?">
  Gasless transactions allow users to interact with blockchain applications **without holding native tokens** (like ETH) to pay for gas fees. Instead, a third party—typically the application developer or a paymaster service—covers the gas costs.

  From the user's perspective, the transaction appears "free," dramatically improving onboarding and user experience.
</Accordion>

<Accordion title="How do gasless transactions work technically?">
  Gasless transactions work through a mechanism called **meta-transactions**:

  1. **User signs a message** describing their intended action (not a transaction)
  2. **Relayer receives** the signed message
  3. **Relayer submits** an actual transaction to the blockchain, paying gas
  4. **Smart contract verifies** the user's signature and executes the action
  5. **Paymaster reimburses** the relayer (in ERC-4337 model)

  ```
  User Intent → Signed Message → Relayer → Blockchain
                                    ↓
                              Paymaster pays gas
  ```

  With ERC-4337, this flow is standardized through UserOperations and Paymasters.
</Accordion>

<Accordion title="What is a Paymaster in ERC-4337?">
  A **Paymaster** is a smart contract that sponsors gas fees for UserOperations. There are different types:

  | Paymaster Type          | Description                              | Use Case                               |
  | ----------------------- | ---------------------------------------- | -------------------------------------- |
  | **Verifying Paymaster** | Sponsors based on off-chain verification | App-specific sponsorship with policies |
  | **Token Paymaster**     | Accepts ERC-20 tokens for gas            | Let users pay gas in USDC, DAI, etc.   |
  | **Deposit Paymaster**   | Uses pre-deposited funds                 | Enterprise gas sponsorship             |

  Biconomy's **MEE** provides all paymaster functionality with additional capabilities like cross-chain gas abstraction—pay for gas on any chain using tokens from any other supported chain.
</Accordion>

<Accordion title="What are the benefits of gasless transactions?">
  **For Users:**

  * ✅ No need to buy/hold ETH before using an app
  * ✅ Familiar Web2-like experience
  * ✅ Lower barrier to entry for new users
  * ✅ Can pay gas in stablecoins if preferred

  **For Developers:**

  * ✅ 10x higher conversion rates on onboarding
  * ✅ Eliminate "buy ETH" support tickets
  * ✅ Control user acquisition costs (sponsor strategically)
  * ✅ Competitive advantage over apps requiring gas

  **For the Ecosystem:**

  * ✅ Mass adoption becomes feasible
  * ✅ Mobile-first experiences possible
  * ✅ Web3 accessible to non-crypto natives
</Accordion>

<Accordion title="How do I implement gasless transactions with Biconomy?">
  Biconomy provides gasless transactions through MEE (Modular Execution Environment):

  **Option 1: AbstractJS SDK (Recommended)**

  ```typescript theme={null}
  import { createMeeClient, toMultichainNexusAccount } from "@biconomy/abstractjs";
  import { base } from "viem/chains";

  const account = await toMultichainNexusAccount({
    signer: userSigner,
    chains: [base]
  });

  const meeClient = await createMeeClient({ account });

  // Get quote with sponsored gas
  const quote = await meeClient.getQuote({
    instructions: [
      { calls: [{ to: contractAddress, data: encodedFunctionCall }] }
    ],
    feeToken: { address: "sponsored" } // Gasless!
  });

  // Execute - user pays nothing
  const { hash } = await meeClient.executeQuote({ quote });
  ```

  **Option 2: Supertransaction API**

  ```bash theme={null}
  curl -X POST "https://api.biconomy.io/v1/quote" \
    -H "x-api-key: YOUR_API_KEY" \
    -d '{
      "sender": "0x...",
      "instructions": [...],
      "feeToken": {
        "address": "sponsored",
        "chainId": 1
      }
    }'
  ```

  MEE handles all the complexity of ERC-4337 (bundlers, paymasters, UserOperations) plus cross-chain orchestration behind the scenes.
</Accordion>

<Accordion title="Can I set limits on gas sponsorship?">
  Yes! MEE supports flexible sponsorship policies configured in the Biconomy Dashboard:

  * **Spending limits**: Max gas per transaction and total spending cap

  Configure these policies in your Biconomy Dashboard, and MEE enforces them automatically when processing transactions.
</Accordion>

<Accordion title="What's the difference between gasless and gas abstraction?">
  | Term                | Meaning                                                     |
  | ------------------- | ----------------------------------------------------------- |
  | **Gasless**         | User pays nothing; sponsor covers 100% of gas               |
  | **Gas Abstraction** | User pays, but in a token of their choice (USDC, DAI, etc.) |

  Both are enabled by the same infrastructure (paymasters), just with different configurations. Gas abstraction is useful when you want users to pay but remove the friction of needing the native token.

  ```typescript theme={null}
  // Gasless (sponsored)
  feeToken: { address: "sponsored" }

  // Gas abstraction (pay in USDC)
  feeToken: { 
    address: "0xA0b86991c...", // USDC
    chainId: 1 
  }
  ```
</Accordion>

<Accordion title="Are gasless transactions safe?">
  Yes, gasless transactions maintain the same security guarantees as regular transactions:

  * **User signature required**: Transactions still need the user's cryptographic signature
  * **Non-custodial**: Sponsors never have access to user funds
  * **On-chain verification**: Smart contracts verify signatures before execution
  * **No replay attacks**: Nonces prevent transaction replay

  The only difference is *who pays* for gas, not *who controls* the transaction.
</Accordion>

<Accordion title="Which EVM chains support gasless transactions?">
  Gasless transactions via ERC-4337 are supported on all major EVM chains:

  * Ethereum Mainnet
  * Arbitrum One & Nova
  * Optimism
  * Base
  * Polygon PoS & zkEVM
  * BNB Chain
  * Avalanche C-Chain
  * And 50+ more chains

  See our [supported chains](/contracts-and-audits/supported-chains) for the complete list.
</Accordion>

***

## Start building gasless apps

<CardGroup cols={2}>
  <Card title="Build a Gasless App" icon="code" href="/faq/build-gasless-web3-app">
    Step-by-step implementation guide
  </Card>

  <Card title="Paymaster Setup" icon="credit-card" href="/faq/erc-4337-paymaster">
    Configure gas sponsorship policies
  </Card>
</CardGroup>