clvm
[Contract Language | Chialisp] Virtual Machine
What it is and what it does
clvm is a virtual machine implementation for Chialisp, a LISP-like smart contract language designed for the Chia blockchain. It interprets and executes Chialisp programs that define conditions for spending cryptocurrency—essentially a runtime for writing contracts that encumber and release funds based on cryptographic proofs and other conditions.
The package is in active development (Alpha status) and maintained by the Chia Network team. It depends on chia_rs for performance-critical operations and uses standard library compatibility shims (importlib_metadata, typing-extensions) for broad Python version support. It's positioned as a developer tool for blockchain engineers building on Chia, not a general-purpose language runtime.
Use it for:
- Building Chia blockchain smart contracts that define spending conditions and fund release logic
- Testing Chialisp programs locally before deployment to a live blockchain network
- Integrating Chia contract execution into Python-based wallet or node software
- Prototyping cryptocurrency payment schemes and escrow logic using Chialisp syntax
Worth the install?
AI-flagged interpretation of the facts on this page — verify before relying
A LISP-like virtual machine for writing and executing smart contracts that control fund encumbrance and release on blockchain networks.
Yes, if you are developing on the Chia blockchain or need to execute Chialisp contracts in Python. The package is actively maintained, has no known vulnerabilities, and installs cleanly. However, it is in Alpha status, so expect API changes and verify production readiness for your use case before committing to it in critical systems.
Install
clvm on PyPI
pip
pip install clvmuv
uv add clvmpoetry
poetry add clvmInstalling clvm
Before you install
Low install friction with a pure-Python wheel distribution. The package is actively maintained with recent commits and supports current Python versions (3.8 through 3.11). Three runtime dependencies keep the dependency tree manageable.
License in practice
Apache 2.0 permissive license allows commercial and private use with minimal restrictions, making it suitable for production deployment in proprietary systems.
Quickstart
pip install clvm
import clvm
# Use the virtual machine to execute Chialisp contracts
# See https://chialisp.com/ for language documentation
Requires Python 3.8.1 or later; depends on chia_rs which may require a Rust toolchain for compilation on some platforms.
Verify before relying
- Whether chia_rs requires compilation from source on all platforms or if pre-built wheels are available
- Performance characteristics and typical execution speed for contract evaluation
- Maturity level beyond 'Alpha' status and production readiness guarantees
Package facts
| License | https://opensource.org/licenses/Apache-2.0 (permissive) |
| Python support | supports the current Python release (<4,>=3.8.1) |
| Install friction | low — pure-Python wheel |
| Runtime dependencies | 3 — chia_rs, importlib_metadata, typing-extensions |
| Maintenance | actively maintained — 331 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 124,789/month — #11,852 on PyPI (30-day window, as of 2026-08-14) |
| Known vulnerabilities | none known (OSV.dev, checked 2026-08-14) |
Evidence: clvm-0.9.15-py3-none-any.whl
Tags
More Cryptography packages
Certifi provides Mozilla's curated collection…
copyleft · top 100 on PyPI
cryptographycryptography provides cryptographic recipes and…
permissive · top 100 on PyPI
rsaPure-Python RSA encryption, decryption,…
permissive · top 1,000 on PyPI
pyOpenSSLpyOpenSSL wraps OpenSSL's SSL/TLS functionality…
permissive · top 1,000 on PyPI
azure-identityProvides Microsoft Entra ID token-based…
unclear · top 1,000 on PyPI
PyNaClPyNaCl provides Python bindings to libsodium…
permissive · top 1,000 on PyPI
clvm-toolsCompiles a LISP-like smart-contract language…
permissive · top 15,000 on PyPI
clvm-rsRust-based implementation of the CLVM virtual…
permissive · top 15,000 on PyPI
clvm-tools-rsCompiles and executes Chialisp programs to CLVM…
permissive · top 15,000 on PyPI
py-evmPy-EVM is a Python implementation of the…
permissive · top 15,000 on PyPI
vyperVyper is a Python-like programming language for…
permissive · top 15,000 on PyPI
chialisp-puzzlesLoads and provides access to standard and…
unclear · top 15,000 on PyPI
eth-brownieBrownie is a Python framework for developing,…
permissive · top 15,000 on PyPI
mythrilMythril analyzes EVM bytecode for security…
permissive · top 15,000 on PyPI
chia-puzzles-pyProvides Python bindings to the standard Chia…
unclear · top 15,000 on PyPI
web3web3.py is a Python library for interacting…
permissive · top 5,000 on PyPI