zkEVM written in Cairo. proof system.
Kakarot is a zkEVM written in Cairo. It aims to allow users to leverage the scaling benefits of validity rollups while maintaining compatibility with the Ethereum ecosystem. Therefore, Kakarot can be used to run Ethereum smart contracts on Starknet.
We strongly believe the CairoVM will provide the best zero-knowledge toolbox in the coming years and that the Ethereum network effect will remain dominant in the meantime. We present to developers an abstraction layer they're familiar with: the EVM. Build and deploy as if you were working on Ethereum, be forward compatible with the future of zero-knowledge.
It is a work in progress, and it is not ready for production.
Latest presentation of Kakarot at Starkware Session TLV 2023
Getting started • Supported opcodes • Build • Test • Report a bug • Questions
Supported opcodes
We support 100% of EVM opcodes.
Documentation
Architecture
-
✅ Kakarot is a smart contract, deployed on Starknet (goerli). It is written in Cairo. -
✅ Kakarot can: (a) execute arbitrary EVM bytecode, (b) deploy an EVM smart contract as is, (c) call a Kakarot-deployed EVM smart contract's functions (views and write methods). -
✅ Kakarot is an EVM bytecode interpreter. -
❌ Kakarot is not a blockchain. -
❌ Kakarot is not a compiler. Check out Warp for a Solidity -> Cairo transpiler
Main execution flow
sequenceDiagram
title Simple bytecode execution flow example: [PUSH1 0x01 PUSH1 0x02 ADD]
actor User
participant Kakarot
participant ExecutionContext
participant EVMInstructions
participant ArithmeticOperations
participant PushOperations
participant Stack
User->>+Kakarot: execute(value, code, calldata)
Kakarot->>+EVMInstructions: generate_instructions()
EVMInstructions->>-Kakarot: instructions
Kakarot->>+ExecutionContext: compute_intrinsic_gas_cost()
ExecutionContext->>-Kakarot: ctx
Kakarot->>Kakarot: run(instructions, ctx)
loop opcode
Kakarot->>+EVMInstructions: decode_and_execute(instructions, ctx)
EVMInstructions->>EVMInstructions: retrieve the current program counter
Note over EVMInstructions: revert if pc < 0, stop if pc > length of code
EVMInstructions->>EVMInstructions: read opcode associated function from instruction set
Note over PushOperations, Stack: x2 PUSH a=1, PUSH b=2
EVMInstructions->>+PushOperations: exec_push1(ctx)
PushOperations->>Stack: push(stack, element)
PushOperations->>-EVMInstructions: ctx
EVMInstructions->>+ArithmeticOperations: exec_add(ctx)
Note over PushOperations, Stack: x2 POP a, POP b
ArithmeticOperations->>Stack: pop(stack)
Stack->>ArithmeticOperations: element
ArithmeticOperations->>Stack: push(stack, result)
ArithmeticOperations->>-EVMInstructions: ctx
EVMInstructions->>-Kakarot: ctx
end
Kakarot->>-User: ctx
Execution sample
Execution of a simple EVM bytecode program on Kakarot.
The bytecode is the following:
6001600503600301610166016002026105b40460020500Which corresponds to the following EVM program:
0x60 - PUSH1
0x60 - PUSH1
0x03 - SUB
0x60 - PUSH1
0x01 - ADD
0x61 - PUSH2
0x01 - ADD
0x60 - PUSH1
0x02 - MUL
0x61 - PUSH2
0x04 - DIV
0x60 - PUSH1
0x05 - SDIV
0x00 - STOPHere is the execution trace of the program on Kakarot:
Getting started
To contribute, please check out the contribution guide.
The easiest way to get started is to use
devcontainers:
- either directly from GitHub to have an online VSCode with everything ready
- or from VSCode, open the project and use "Dev Containers: Rebuild container" (requires Docker on your host machine)
Otherwise, you can proceed with a regular installation on your host:
# install poetry if you don't have it already
# curl -sSL https://install.python-poetry.org | python3 -
make setupBuild
To build the Cairo files:
make buildTo build the test Solidity smart contracts:
# install foundry if you don't have it already
# curl -L https://foundry.paradigm.xyz | bash
# foundryup
make build-solTest
# Run all tests
make test
# Run only unit tests
make test-units
# Run only integration tests
make test-integration
# Run a specific test file
pytest <PATH_TO_FILE> # with pytest
python3 -m unittest <PATH_TO_FILE> # with unittest
# Run a specific test mark (markers in pyproject.toml)
make run-test-mark mark=<MARK>
make run-test-mark-log mark=<MARK> # with logTest architecture is the following:
- tests/unit/src contains cairo tests for each cairo function in the kakarot codebase
- tests/integration/bytecode contains python tests for kakarot execute() function with forged bytecode
- tests/integration/solidity_contracts contains python tests for solidity contracts that are compiled, deployed on kakarot local node and interacted with kakarot eth_call() and invoke()
- the project also contains some forge tests (e.g.
PlainOpcodes.t.sol) whose purpose is to test easily the solidity functions meant to be tested with kakarot, i.e. quickly making sure that they return the expected output so that we know that we focus on kakarot testing and not .sol testing. They are not part of the CI. Simply useforge testto run them.
Deploy
The following describes how to deploy the entire Kakarot EVM on StarkNet.
It is not a description on how to deploy a contract on the official Kakarot zkEVM.
The Kakarot EVM can be deployed on StarkNet using a python script utilizing the starknet.py library.
First we need to declare some environment variables that are required for the deployment.
Start by copying the .env_example file located in the root directory (.files
are usually hidden by default in most explorers. You should be able to see the
file in your IDE).
Rename the copied file to .env.
The file holds the following content:
PRIVATE_KEY=your_private_key
ACCOUNT_ADDRESS=your_account_address
Now replace the placeholder values with your account and network details.
PRIVATE_KEY is the private key of the account contract that will pay for the
deployment. This should be a decimal number
ACCOUNT_ADDRESS is the address of the account contract that will pay for the
deployment (not the public key). This should be a hexadecimal number
Here is a concrete example:
PRIVATE_KEY=72893439023848923y4138741073892473874203487234872208352937239047293428374088
ACCOUNT_ADDRESS=0x06e5d623aBe979c3DEFf52bE6DF5116352C12Ee21428D5b2CF91cA440c4edBD0
By default, everything will run on a local starknet-devnet (started with
make run). If you want to deploy to a given target, set the STARKNET_NETWORK
env variable, for example:
make deploy # localhost
STARKNET_NETWORK=testnet make deploy
STARKNET_NETWORK=testnet2 make deploy
STARKNET_NETWORK=mainnet make deployDeployed contract addresses will be stored in
./deployments/{networks}/deployments.json.
A step by step description of the individual components and how they are deployed/configured can be found here.
License
kakarot is released under the MIT.
Security
Kakarot follows good practices of security, but 100% security cannot be assured. Kakarot is provided "as is" without any warranty. Use at your own risk.
For more information and to report security issues, please refer to our security documentation.
Callgraphs
The callgraph artifacts contains all the contract's call graph. Those are generated using thoth and can provide some more insight on the inside of this zkEVM. The legend can be found here. You can use this tool to visualize the .gv files online.
Questions / FAQ
Questions are welcome! If you have any questions regarding Kakarot, feel free to ask them using Newton.
FAQ
- What is Kakarot, the zkEVM written in Cairo?
- Is Kakarot zkEVM a blockchain?
- When will Kakarot zkEVM launch on mainnet?
- Does Kakarot zkEVM have a token?
- Is Kakarot zkEVM a smart contract or a blockchain?
- Is Kakarot a Starkware project?
- Is Kakarot part of the Starknet ecosystem?
- Will Kakarot be an L3 on top of the Starknet validity rollup?
- Can I add Kakarot to my metamask?
- Is Kakarot equivalent to Arbitrum?
Contributing
First off, thanks for taking the time to contribute! Contributions are what make the open-source community such an amazing place to learn, inspire, and create. Any contributions you make will benefit everybody else and are greatly appreciated.
Please read our contribution guidelines, and thank you for being involved!
Contributors
