A Vyper interpreter with pretty tracebacks, forking, debugging features and more! Titanoboa's goal is to provide a modern, advanced and integrated development experience for vyper users.
Titanoboa achieves feature parity with the vyper compiler while providing an interpreted experience. How does it do this? Internally, titanoboa uses vyper as a library to compile source code to bytecode, and then runs the bytecode using py-evm, adding instrumenting hooks to provide introspection. The use of py-evm means that the entire experience is highly configurable, down to the ability to patch opcodes and precompiles at the EVM level.
Usage and quickstart are below. For more detailed documentation, please see the documentation.
pip install titanoboa
For latest dev version:
pip install git+https://github.com/vyperlang/titanoboa
If you are installing titanoboa from git alongside brownie, you may have to manually install titanoboa after installing brownie
pip install brownie
pip install git+https://github.com/vyperlang/titanoboa
Sometimes, using pypy can result in a substantial performance improvement for computation heavy contracts. Pypy can usually be used as a drop-in replacement for CPython.
To get a performance boost for mainnet forking, install with the forking-recommended extra (pip install "git+https://github.com/vyperlang/titanoboa#egg=titanoboa[forking-recommended]", or pip install titanoboa[forking-recommended]). This installs plyvel to cache RPC results between sessions, and ujson which improves json performance.
If you are running titanoboa on a local Vyper project folder, you might need to run python setup.py install on your Vyper project if you encounter errors such as ModuleNotFoundError: No module named 'vyper.version'
Titanoboa (/ˌtaɪtənəˈboʊə/;[1] lit. 'titanic boa') is an extinct genus of very large snakes that lived in what is now La Guajira in northeastern Colombia. They could grow up to 12.8 m (42 ft), perhaps even 14.3 m (47 ft) long and reach a body mass of 730–1,135 kg (1,610–2,500 lb). This snake lived during the Middle to Late Paleocene epoch, around 60 to 58 million years ago, following the extinction of all non-avian dinosaurs. Although originally thought to be an apex predator, the discovery of skull bones revealed that it was more than likely specialized in preying on fish. The only known species is Titanoboa cerrejonensis, the largest snake ever discovered,[2] which supplanted the previous record holder, Gigantophis garstini.[3]
import boa
boa.eval("empty(uint256)")# simple.vy
@external
def foo() -> uint256:
x: uint256 = 1
return x + 7>>> import boa
>>> simple = boa.load("examples/simple.vy")
>>> simple.foo()
8
>>> simple.foo()._vyper_type
uint256>>> import boa
>>> erc20 = boa.load("examples/ERC20.vy", 'titanoboa', 'boa', 18, 1)
>>> erc20.name()
titanoboa
>>> erc20.symbol()
boa
>>> erc20.balanceOf(erc20.address)
0
>>> erc20.totalSupply()
1000000000000000000>>> import boa
>>> s = boa.load_partial("examples/ERC20.vy")
>>> blueprint = s.deploy_as_blueprint()
>>> deployer = boa.load("examples/deployer.vy", blueprint)
>>> token = s.at(deployer.create_new_erc20("token", "TKN", 18, 10**18))
>>> token.totalSupply()
>>> 1000000000000000000000000000000000000>>> import boa
>>> erc20 = boa.load("examples/ERC20.vy", "titanoboa", "boa", 18, 0)
>>> with boa.env.prank(boa.env.generate_address()):
... with boa.reverts():
... erc20.mint(boa.env.eoa, 100) # non-minter cannot mint
...
>>> with boa.env.prank(boa.env.generate_address()):
... # you can be more specific about the failure reason
... with boa.reverts(rekt="non-minter tried to mint"):
... erc20.mint(boa.env.eoa, 100)In [1]: %load_ext boa.ipython
import boa
boa.interpret.set_cache_dir() # cache source compilations across sessions
In [2]: %vyper msg.sender # evaluate a vyper expression directly
Out[2]: '0x0000000000000000000000000000000000000065'
In [3]: %%vyper
...:
...: MY_IMMUTABLE: immutable(uint256)
...:
...: @external
...: def __init__(some_number: uint256):
...: MY_IMMUTABLE = some_number * 2
...:
...: @external
...: def foo() -> uint256:
...: return MY_IMMUTABLE
...:
Out[3]: <boa.vyper.contract.VyperDeployer at 0x7f3496187190>
In [4]: d = _
In [4]: c = d.deploy(5)
In [5]: c.foo()
Out[5]: 10>>> erc20 = boa.load("examples/ERC20.vy", 'titanoboa', 'boa', 18, 1)
>>> erc20.balanceOf(erc20.address)
0
>>> erc20.totalSupply()
1000000000000000000
>>> erc20.eval("self.totalSupply += 10") # manually mess with total supply
>>> erc20.totalSupply()
1000000000000000010
>>> erc20.eval("self.totalSupply") # same result when eval'ed
1000000000000000010
>>> erc20.eval("self.balanceOf[msg.sender] += 101") # manually mess with balance
>>> erc20.balanceOf(boa.env.eoa)
1000000000000000101
>>> erc20.eval("self.balanceOf[msg.sender]") # same result when eval'ed
1000000000000000101Note that in eval() mode, titanoboa uses slightly different optimization settings, so gas usage may not be the same as using the external interface.
Create a fork of mainnet given rpc.
In [1]: import boa; boa.env.fork(url="<rpc server address>")
In [2]: %load_ext boa.ipython
In [3]: %%vyper Test
...: interface HasName:
...: def name() -> String[32]: view
...:
...: @external
...: def get_name_of(addr: HasName) -> String[32]:
...: return addr.name()
Out[3]: <boa.vyper.contract.VyperDeployer at 0x7f3496187190>
In [4]: c = Test.deploy()
In [5]: c.get_name_of("0xD533a949740bb3306d119CC777fa900bA034cd52")
Out[5]: 'Curve DAO Token'Cast current deployed addresses to vyper contract
>>> import boa; boa.env.fork(url="<rpc server address>")
>>> c = boa.load_partial("examples/ERC20.vy").at("0xD533a949740bb3306d119CC777fa900bA034cd52")
>>> c.name()
'Curve DAO Token'>>> import boa; from boa.network import NetworkEnv
>>> from eth_account import Account
>>> boa.env.set_env(NetworkEnv("<rpc server address>"))
>>> # in a real codebase, always load private keys safely from an encrypted store!
>>> boa.env.add_account(Account(<a private key>))
>>> c = boa.load("examples/ERC20.vy", "My Token", "TKN", 10**18, 10)
>>> c.name()
'My Token'You can use Jupyter to execute titanoboa code in network mode from your browser using any wallet, using boa.integrations.jupyter.BrowserSigner as a drop-in replacement for eth_account.Account. For a full example, please see this example Jupyter notebook
$ python -m tests.integration.sim_veYFI