Account Abstraction Bundler Simulation Tool

WHAT IT DOES

Account Abstraction Bundler Simulation Tool provides comprehensive simulation of ERC-4337 account abstraction bundler execution. It retrieves on-chain EntryPoint contract bytecode via eth_getCode and fetches verified source code and ABI from block explorer APIs. The tool analyzes UserOperation data and bundler transaction bundles, validates account factory and wallet contract bytecode, and simulates the bundler's execution flow. It runs a suite of validation checks including UserOperation format validation, sender account validation, signature verification, paymaster validation, gas estimation, and full bundler execution simulation. The output includes a simulation status (Success, Partial, or Failed), count of validated UserOperations, estimated total gas, a detailed UserOperation list showing each operation's validity, a check matrix showing each validation check's result, and actionable recommendations for resolving issues—such as malformed UserOperations, invalid signatures, insufficient gas, or paymaster errors. This enables AA bundler operators, wallet developers, and infrastructure engineers to test and debug bundler behavior before deploying to production, ensuring that UserOperations are correctly processed and gas costs are properly estimated.

HOW TO USE

Connect your BGWallet to the target EVM chain. Paste the address of the ERC-4337 EntryPoint contract you wish to test. Provide UserOperation data as a JSON array containing the operations to be bundled—including fields like sender, nonce, initCode, callData, callGasLimit, verificationGasLimit, preVerificationGas, maxFeePerGas, maxPriorityFeePerGas, paymasterAndData, and signature. Optionally supply a GitHub repository URL to pull AA implementation details and bundler specifications for additional context. The tool fetches the EntryPoint contract's bytecode and state, analyzes the provided UserOperations, and runs a comprehensive bundler simulation. Review the simulation status, validated count, gas estimate, UserOperation details, check matrix, and recommendations. Use the results to verify that your bundler implementation correctly handles UserOperations and that gas estimates are accurate before submitting bundles on-chain.

ACCOUNT ABSTRACTION BUNDLER SIMULATION AND VALIDATION ENGINE

The real technical mechanism is the account abstraction bundler simulation and validation engine that combines EntryPoint bytecode analysis with ERC-4337 operation semantics. The tool first analyzes the EntryPoint contract's bytecode to identify the handleOps function and the validation logic for UserOperations—including signature verification, paymaster checks, and account factory validation. It then parses the provided UserOperation array, validating each operation's format and content against the ERC-4337 specification. The engine simulates the bundler's execution flow by walking through the handleOps function's logic: validating each UserOperation's signature against the sender's account, verifying that the sender account exists (or can be created via initCode), checking paymaster validation if provided, and estimating gas costs for each operation. The simulation also accounts for gas overhead and bundler-specific constraints such as maximum bundle size and gas limits. The engine identifies specific validation failures—such as invalid signatures, insufficient verification gas, or paymaster rejection—and provides detailed error context. The gas estimation component computes the total gas cost for the bundle, including per-operation gas limits and the EntryPoint's fixed overhead. This approach provides developers with a comprehensive, automated way to test AA bundler behavior, catching issues that would otherwise only surface during live bundling and preventing failed transactions or wasted gas.

WHAT IT CANNOT SEE

This tool cannot generate a complete bundler simulation without access to EntryPoint bytecode or UserOperation data. It is limited by your RPC provider's rate limits for data retrieval, which may delay analysis on congested networks. It cannot determine if UserOperations are correctly validated without executing simulation—static analysis provides insights but does not replace full handleOps execution. The detection relies on the completeness of the ABI and source code verification; unverified contracts or incomplete verification data will produce incomplete or inaccurate results. Detection is based on bytecode pattern matching and may miss indirect or obfuscated bundler logic, such as validation logic hidden in libraries or via delegate calls. The tool cannot assess runtime behavior or gas implications of bundler execution, such as how gas costs vary with different operation types or network conditions. It may produce false positives for data that appears similar to UserOperation data but is used for other purposes. The tool does not execute the contract to validate simulation, so it cannot confirm that the simulated behavior matches actual on-chain execution. It cannot account for network-specific AA implementation differences or future upgrades—different chains may have different EntryPoint implementations or modifications to ERC-4337. Account Abstraction implementation may vary across chains and change over time as standards evolve.

PLEASE NOTE

This tool works exclusively with EVM-compatible chains that support ERC-4337 account abstraction. It requires active internet connectivity to access block explorer APIs and RPC endpoints. Some block explorers may require API keys for high-volume bytecode retrieval. The tool is read-only and does not execute any transactions—it only produces simulation assessments. Account abstraction bundler behavior is critical to AA infrastructure; always verify simulation results against actual bundler test runs and test on testnet before mainnet deployment. Different chains may use different EntryPoint addresses and AA implementations.