The cannon (cannon cannon cannon) is an on chain interactive fraud prover

It’s half geth, half of what I think truebit was supposed to be. When it’s done, we’ll be able to prove L1 blocks aren’t fraud

  1. Get minigeth to verify a block locally paying attention to oracle (done)
  2. Compile embedded minigeth to MIPS (done)
  3. Get embedded minigeth to verify a block using the oracle (done)
  4. Merkleize the state of the embedded machine
  5. Write Solidity code to verify any MIPS/oracle transitions
  6. Write binary search engine to play on chain game

…and then there’s more stuff, but just that for now.

The system is checking an embedded block in CI now

  • TODO: Fix missing trie nodes see issue
  • TODO: Stub all syscalls after it’s “booted”


  • Finish and test the MIPS state transition function in contracts/MIPS.sol
  • Get minigeth running in Solidity MIPS emulator with reasonable performance (Go code using EVM with native memory)
  • Add merkleization for MIPS ReadMemory and WriteMemory


# verify the transition from 13284469 -> 13284470

State Oracle API

Preimage(hash) -> value # hash(value) == hash

PrefetchAccount, PrefetchStorage, PrefetchCode can be NOP in the VM


All my code is MIT license, minigeth is LGPL3. Being developed under contract for @optimismPBC

Very important TODO

TODO: update to picture of increasingly futuristic cannon as it starts to work