vyper

library0.4.3pypypi✓ verified 86d ago

Vyper is a Pythonic programming language for the Ethereum Virtual Machine (EVM), designed with security, auditability, and simplicity in mind. It provides a more constrained set of features compared to other EVM languages, aiming to reduce complexity and potential vulnerabilities. The current version is 0.4.3, with minor releases and release candidates occurring frequently, typically leading to stable minor versions every few months.

database http-networking auth-security

pip install vyper

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · VYPER

vyper

databasepythonv0.4.3

Install

2.8s avg

Import

420ms

Disk

31MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.4.3 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.910 runs

installs and imports cleanly · install 0.0s · import 0.432s · 32.2MB

glibc

py 3.10–3.910 runs

installs and imports cleanly · install 2.8s · import 0.408s · 34MB

31MB installed

● package 31MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

compile_code

✓ from vyper import compile_code

✗ import vyper.compiler

The primary programmatic compilation function `compile_code` is directly available from the top-level package.

This quickstart demonstrates how to programmatically compile a basic Vyper smart contract using the `compile_code` function. It specifies the desired output formats (bytecode and ABI) and an EVM version for compilation, then prints the resulting artifacts.

from vyper import compile_code contract_code = ''' # @version ^0.4.0 # A simple Vyper contract @external def hello() -> String[100]: return "Hello, Vyper!" ''' # Compile the contract to get bytecode, ABI, and other artifacts compiled_artifacts = compile_code( contract_code, output_formats=['bytecode', 'abi'], evm_version='shanghai' # Specify EVM version for compatibility ) print("Bytecode:", compiled_artifacts['bytecode']) print("ABI:", compiled_artifacts['abi'])

vyper --version

Debug

Known issues

breakingVyper adheres to a `0.x.x` versioning scheme, meaning breaking changes can occur in minor releases. Always review release notes when upgrading between `0.X.x` versions (e.g., from 0.3.x to 0.4.x).

fix

Consult the official Vyper release notes (docs.vyperlang.org/en/latest/release-notes.html) for specific upgrade instructions and breaking changes.

affects: <1.0.0

breakingThe default EVM version targeted by the compiler can change in minor releases (e.g., to 'prague' in v0.4.3). This might affect bytecode generation and compatibility with specific chain deployments if not explicitly handled.

fix

Always explicitly specify the target EVM version using the `evm_version` parameter in `compile_code` or the `--evm-version` CLI flag to ensure consistent bytecode across environments.

affects: All versions

gotchaVyper requires Python 3.10 or higher, but strictly less than Python 4.0. Running with an unsupported Python version will lead to installation or runtime errors.

fix

Ensure your environment uses a compatible Python version (e.g., `python3.10` or `python3.11`). Use `pyenv` or `conda` for managing Python versions if necessary.

affects: All versions

breakingRecent releases (e.g., v0.4.1) have included security-related fixes for low-to-moderate severity vulnerabilities. Older versions may contain known security flaws.

fix

Always use the latest stable version of Vyper to benefit from critical security patches. Regularly check the official Vyper GitHub for security advisories.

affects: <0.4.1

gotchaExperimental compiler features, such as the `--venom` or `--experimental-codegen` flags (aliases), are subject to rapid change, may contain bugs, or produce unoptimized/unexpected bytecode. They are not recommended for production deployments.

fix

Avoid using experimental features in production. If used for development, be aware of potential instabilities and thoroughly test generated bytecode.

affects: All versions with experimental features

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'vyper'

The Vyper library has not been installed in the current Python environment.

fix

Run `pip install vyper` to install the library.

SyntaxException: line X:X 'some_invalid_keyword' is not allowed

There is a syntax error or an attempt to use a non-existent keyword or feature in your Vyper contract code.

fix

Review the Vyper contract code against the official Vyper documentation for the specific version you are using. Vyper has a minimalist design, so many Solidity features are not present.

ValueError: Vyper does not support python version 3.9.x (or similar for other unsupported versions)

You are attempting to run Vyper with an unsupported Python version. Vyper typically requires Python 3.10+ but less than 4.

fix

Switch your Python environment to a compatible version (e.g., 3.10, 3.11, 3.12). You can use `pyenv install 3.12.0 && pyenv local 3.12.0` or create a new virtual environment with the correct Python version.

KeyError: 'bytecode' (or 'abi') when accessing compiled_artifacts

The specified `output_formats` in `compile_code` did not include the key you are trying to access, or compilation failed silently without producing all artifacts.

fix

Ensure that the `output_formats` list explicitly includes all the keys you intend to access (e.g., `['bytecode', 'abi', 'ast_dict']`). Check for compilation errors if outputs are still missing.

Upgrade

Version history

0.4.3latest on PyPI · released Jun 18, 2025

Audit

Dependencies

No dependency data recorded yet.

Agent activity

23 hits · last 30 days

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