z3-solver
an efficient SMT solver library
Decision gist · record as of 2026-08-14
Yes, if you need to solve constraint satisfaction or logical satisfiability problems. Z3 is a mature, actively maintained solver from a reputable source with no known vulnerabilities and permissive licensing. Install friction is moderate but manageable via pre-built wheels. Not necessary for general-purpose Python development but essential for formal verification, automated testing, or constraint-based reasoning tasks.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Medium install friction due to platform-specific binary wheels (Windows, macOS, Linux variants); however, pre-built binaries are available for common architectures.
- Single lightweight runtime dependency (importlib-resources).
- Active maintenance with recent release (28 days old) and strong repository signals (12560 stars, current as of 2026-08-14).
License · maintenance · safety
MIT License (permissive) — MIT License permits commercial and private use with minimal restrictions. Windows binary distributions include C++ runtime redistributables, which may require acceptance of additional license terms from Microsoft.
last release 2026-07-17 (28 days) · last repo commit 2026-08-14 · 12,560 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 6,097,257 downloads/mo, #1,971 on PyPI
Alternatives
Verify before relying
pip install z3-solver
from z3 import *
x = Int('x')
s = Solver()
s.add(x > 2, x < 10)
if s.check() == sat:
print(s.model())- Whether Python version support is truly unspecified or if there are practical minimum/maximum version constraints
- Performance characteristics and scalability limits for large constraint problems
- Whether the package is suitable for production use or primarily for research/prototyping
What it is and what it does
Z3 is a theorem prover and SMT solver developed by Microsoft Research that determines whether logical formulas are satisfiable and computes models that satisfy them. It handles formulas across multiple theories including integer and real arithmetic, bit-vectors, arrays, and uninterpreted functions. The package provides Python bindings to the underlying C++ solver engine, distributed as pre-built binaries for Windows, macOS, and Linux architectures.
Developers use Z3 to solve constraint satisfaction problems, verify program properties, test software systematically, and reason about complex logical statements. It is commonly applied in formal verification, program analysis, security research, and automated testing. The solver combines SAT solving with theory-specific decision procedures to handle both propositional and quantified formulas efficiently.
Use it for
- Verify that program logic satisfies safety properties or invariants before deployment
- Generate test cases automatically by solving constraints that exercise specific code paths
- Analyze security properties of cryptographic protocols or access control policies
- Solve constraint satisfaction problems in optimization, scheduling, or resource allocation
- Check satisfiability of mathematical formulas in formal methods and theorem proving
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need to solve constraint satisfaction or logical satisfiability problems.
Z3 is a mature, actively maintained solver from a reputable source with no known vulnerabilities and permissive licensing. Install friction is moderate but manageable via pre-built wheels. Not necessary for general-purpose Python development but essential for formal verification, automated testing, or constraint-based reasoning tasks.
Install
z3-solver on PyPI
Before you install
Medium install friction due to platform-specific binary wheels (Windows, macOS, Linux variants); however, pre-built binaries are available for common architectures. Single lightweight runtime dependency (importlib-resources). Active maintenance with recent release (28 days old) and strong repository signals (12560 stars, current as of 2026-08-14).
License in practice
MIT License permits commercial and private use with minimal restrictions. Windows binary distributions include C++ runtime redistributables, which may require acceptance of additional license terms from Microsoft.
Quickstart
pip install z3-solver
from z3 import *
x = Int('x')
s = Solver()
s.add(x > 2, x < 10)
if s.check() == sat:
print(s.model())Verify before relying
- Whether Python version support is truly unspecified or if there are practical minimum/maximum version constraints
- Performance characteristics and scalability limits for large constraint problems
- Whether the package is suitable for production use or primarily for research/prototyping
Package facts
| License | MIT License permissive |
| Python support | Not specified |
| Install friction | Medium. Platform-specific wheel |
| Runtime dependencies | 1 packageimportlib-resources |
| Maintenance | Actively maintained 28 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 6,097,257 / month, #1,971 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
Evidence: z3_solver-5.0.0.0-py3-none-macosx_13_0_arm64.whl; z3_solver-5.0.0.0-py3-none-macosx_13_0_x86_64.whl; z3_solver-5.0.0.0-py3-none-manylinux_2_27_x86_64.whl; z3_solver-5.0.0.0-py3-none-manylinux_2_38_aarch64.whl; z3_solver-5.0.0.0-py3-none-manylinux_2_38_riscv64.whl; z3_solver-5.0.0.0-py3-none-win32.whl; z3_solver-5.0.0.0-py3-none-win_amd64.whl; z3_solver-5.0.0.0-py3-none-win_arm64.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “SMT solver”
- z3-solverZ3 is a theorem prover and SMT (satisfiability modulo theories)…
- PyBoolectorPython wrapper around Boolector, a Satisfiability Modulo Theories…
- cvc5cvc5 is a satisfiability modulo theories (SMT) solver that determines…
Give your agent the search over MCP, or paste the wish link into any chat.
More Mathematics packages
NetworkX provides data structures and algorithms for creating, analyzing, and manipulating graphs and networks, supporting everything from simple undirected graphs to complex directed and weighted networks.
kiwisolver is a Python binding to a fast C++ implementation of the Cassowary constraint solver, enabling you to solve systems of linear constraints and inequalities.
Install it if you need to solve constraint systems; skip it if you only need simple linear algebra.
SymPy is a Python library for symbolic mathematics, performing algebraic manipulation, calculus, equation solving, and mathematical expression simplification without numerical approximation.
ContourPy calculates contours of 2D quadrilateral grids using C++11 algorithms wrapped in Python, offering serial and multithreaded implementations without requiring Matplotlib as a dependency.
PyTorch provides GPU-accelerated tensor computation and automatic differentiation for building and training deep neural networks in Python.
onnxruntime loads and executes Open Neural Network Exchange (ONNX) models with a focus on inference performance across CPUs and accelerators.
Install it if you have ONNX models to run in production or development.
See also claripy · cvc5 · PyBoolector · pyvcg · lean-lsp-mcp · simplesat · pycosat · crosshair-tool · chiapos · python-sat