How is it possible that the Safe UI is able to simulate a call to execTransaction via Tenderly before collecting the signatures?

See this simulation, it succeeds even tho it only contains a single signature. It's a 2-of-4 setup, so it should fail with GS020 for not having enough signatures. screenshot of simulation showing a single signature in the input

I thought Tenderly executes transactions against the real contracts, but seems like some of my assumptions are wrong about the way Tenderly and/or Gnosis Safe works.

1 Answer 1


With tenderly it is possible to overwrite the contract storage for a simulation and that's what the safe interface does: it overwrites the threshold in storage to 1 and uses a msg.sender signature from one of the owners.

  • 1
    ok that makes sense, thx a lot 🤝
    – Tech Capo
    Commented Jan 19, 2023 at 17:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.