# Account Abstraction Explorer

> Decode ERC-4337 bundles: UserOperations, paymasters, gas per op, deployed smart accounts. Decodes ERC-4337 EntryPoint v0.6/v0.7/v0.8 events in a bundle transaction — every UserOperation with its sender, paymaster sponsorship, success, gas cost and revert reason, plus newly deployed accounts and the bundler's margin. For a smart-account address it shows the code type, EIP-7702 delegation, EntryPoint nonces and deposits and the proxy implementation.

Part of usefulweb.site (https://usefulweb.site/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://accountabstractionexplorer.usefulweb.site/ (interactive tool at https://accountabstractionexplorer.usefulweb.site/tool)
- JSON API: POST https://accountabstractionexplorer.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://accountabstractionexplorer.usefulweb.site/api/v1/tool)
- OpenAPI: https://accountabstractionexplorer.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://accountabstractionexplorer.usefulweb.site/mcp - tool `account_abstraction_explorer`

## Inputs
- mode (select): What do you have?
- chain (select): Chain
- txHash (text): Transaction hash
- address (text): Smart account address
- receipt (textarea): Receipt JSON - A transaction receipt ({from, gasUsed, effectiveGasPrice, logs:[…]}) or just the logs array.

## Method
- EntryPoint events are matched by topic0 computed locally from the signatures UserOperationEvent(bytes32 indexed userOpHash, address indexed sender, address indexed paymaster, uint256 nonce, bool success, uint256 actualGasCost, uint256 actualGasUsed), UserOperationRevertReason, PostOpRevertReason and AccountDeployed.
- Known EntryPoints: v0.6 0x5FF137D4…2789, v0.7 0x00000000…a032 and v0.8 0x4337084D…f108 (deployed at the same address on every chain; checked with eth_getCode). Events from any other emitter are decoded but flagged.
- Bundler = the transaction sender (tx.from). Bundler margin = sum of actualGasCost charged to the UserOperations minus the transaction fee actually paid; it assumes the handleOps beneficiary is the bundler.
- Nonce = 192-bit key << 64 | 64-bit sequence (ERC-4337 semi-abstracted nonce). Revert data is decoded as Error(string)/Panic(uint256) or shown as a custom-error selector.
- Account mode: eth_getCode (0xef0100‖address = EIP-7702 delegation), eth_getBalance, EntryPoint.getNonce(account, 0) and balanceOf(account) (deposit) on each EntryPoint, and the Contract Upgrade Explorer for the proxy implementation.