Scope

✨ UserOp Simulation ✨

Scope now has a built-in 4337 simulator.

1. Tailored UI

The page header features the most important properties of an operation, including sender, factory, calldata, and more.

The traces are split into 4337 phases (creation / validation / payment / execution).

2. Error handling

If the operation is failed, the exact error is highlighted at top.

The phase in which the error has happened is also highlighted.

3. Permalinks

Each simulation has a permalink that is easy to share.

4. Labels

Known paymasters and factories are rendered with the corresponding icon and label

5. Input validation

It validates the input and shows the exact issue with the JSON data.

It also accepts both compact and unpacked representations of the operation.

In most cases, simply copying the UserOp JSON from e.g. @pimlico should work.

This is an early release!

Things I'd like to improve:

1. Be able skip certain phases (e.g. validation)
2. Handle more input formats (e.g. native JS objects)
3. Block number override
4. Improve the error handling (e.g catch failed ECDSA precompile calls)

Here's a link to an example if you want to see it live:

Here's a link to an example if you want to see it live:

https://t.co/lXvhQiVVmM

There are a few EVM debugging tools already, e.g. Tenderly.

Why make another one?

This one is built specifically to debug 4337 userops.

what are you simulating w under the hood -- viem?