Smart Account Execution Environments
When interacting onchain with Smart Accounts, the users don't post the transactions themselves on the blockchain. Instead,
they use more advanced transaction data models - in the case of Biconomy infra - UserOps and Supertransactions!
These data models contain extra information which a normal onchain transaction doesn't have. This can include anything from gas sponosorship information and batch execution instructions in UserOps, to multi-chain execution sequences and cross-chain composability instructions in Supertransactions.
In order to convert these complex data objects into transactions and post them onchain, Smart Account users use Execution Environments.
Types of Execution Environments
Bundlers and Paymasters
The most common type of a Smart Account execution environment is the ERC4337 Bundler & Paymaster stack. In this execution environment the Bundler parses the UserOp data model and posts the function calls contained within it onchain. If the developer decides to sponsor the user transactions or enable users to pay for gas with ERC20 tokens - they can enable a Paymaster, which takes care of that functionality.
Learn more about Bundlers and Paymasters
Modular Execution Environment
The Modular Execution Environment, or MEE - is an innovative execution environment standard - developed by Biconomy. MEEs enable much more complex transaction sequences to be executed than just Bundlers and Paymasters. Beyond supporting just transactions, Modular Execution Environments support both the execution of intents and transactions. Additionally, MEEs were build with the future in mind - with an elegant mechanism which can provide execution across 1000+ blockchains, rollups and appchains.