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Prerequisites: This tutorial assumes you’ve read the Enable MEE for EOA Users and understand EIP-7702 based execution and Fusion execution.
Gas sponsorship in Biconomy MEE allows developers to fully abstract gas costs from end-users—regardless of wallet type or chain. Whether you’re building on embedded wallets with EIP-7702, using native smart contract accounts, or orchestrating through Fusion from EOAs like MetaMask, MEE provides a unified, scalable sponsorship model.
Simplify Your Operations: One gas tank. Many chains. Sponsorships can be powered across all supported chains from a single gas tank and infrastructure.
This guide will:
  • Introduce sponsorship across EIP-7702, Fusion, and native SCAs
  • Help you choose the right flow for your app
  • Walk you through enabling sponsorship
  • Explain hosted vs self-hosted setups

Sponsorship Basics

Biconomy’s gas sponsorship abstracts the need for end-users to hold native gas. This is ideal for:
  • Onboarding users unfamiliar with wallets
  • Consumer apps where gas UX is a blocker
  • Advanced orchestrations involving bridging or multicalls
Sponsorship is activated per-project via dashboard.biconomy.io and requires an apiKey in all requests.

Choosing the Right Flow

EIP-7702 Sponsorship (Embedded Wallets)

EIP-7702 lets you install smart account logic directly on EOAs, enabling orchestration and sponsorship with zero user effort.
Full Support: Supports all ERC-20s, multichain execution, and full transaction abstraction.
Best For: Embedded wallets (Privy, Dynamic, Turnkey, …)

Fusion Sponsorship (External Wallets)

Fusion enables orchestration from EOAs (e.g. MetaMask) via a trigger + Companion Account pattern. It supports sponsorship, but with caveats:

Requirements

  • Set sponsorship: true
  • Trigger token must support permit() (ERC-2612) to be truly gasless
  • Otherwise, user must have enough native gas to approve() token transfer
Best For: External Wallets - MetaMask, Trust, Rabby, Coinbase Wallet, Uniswap Wallet, …

Native SCA Sponsorship (Deployed Accounts)

If you’re orchestrating via pre-deployed smart contract accounts, you can sponsor transactions as long as the orchestrator account is set and you pass the apiKey.
Works across any chain MEE supports. Best for dApps that deploy user accounts up front.

Hosted vs Self-Hosted Sponsorship

  • No infra required
  • Uses Biconomy-managed gas tanks
  • Set up via dashboard
  • Supports post-paid modes with enterprise contracts or paying via credit card

Testnet Setup

On testnets, you’ll often want to use sponsorshipOptions to point to a testnet gas tank:

Discover Available Gas Tanks

List available tanks using:
Or point to your self-hosted sponsorship URL to list custom tanks.

Summary

  • Use EIP-7702 for embedded wallets — simplest and most powerful
  • Use Fusion for EOAs — ensure permit() or fallback gas is available
  • Use native SCAs if deploying and managing accounts
  • Start with Biconomy-hosted sponsorship; move to self-hosted as you scale
  • Sponsorship unlocks full UX abstraction with one gas tank across all chains
Sponsorship is the easiest way to eliminate onboarding friction and scale user-friendly smart account experiences.