.NET API Installation

Install and configure Z3 for .NET applications

The Z3 .NET API provides a managed interface to Z3 for .NET, C#, F#, and other .NET languages.

Prerequisites

• .NET Framework 4.5+ or .NET Core 2.0+ or .NET 5+
• Visual Studio (recommended) or any .NET-compatible IDE
• NuGet package manager

Installation Options

Option 1: NuGet Package (Recommended)

The easiest way to use Z3 in .NET projects is via the official NuGet package.

Package Manager Console

Install-Package Microsoft.Z3

.NET CLI

dotnet add package Microsoft.Z3

PackageReference

Add to your .csproj file:

<ItemGroup>
  <PackageReference Include="Microsoft.Z3" Version="4.*" />
</ItemGroup>

The NuGet package includes native binaries for Windows, Linux, and macOS, so no additional configuration is needed.

Option 2: Pre-built Binaries

Download from the GitHub Releases page.

1. Download Z3

   Download the appropriate package:

   • Windows: z3-x.x.x-x64-win.zip
   • Linux: z3-x.x.x-x64-glibc-x.x.zip
   • macOS: z3-x.x.x-x64-osx-x.x.zip
2. Extract Archive

   Extract to a location (e.g., C:\z3).

3. Locate .NET Files

   The bin directory contains:

   • Microsoft.Z3.dll - .NET assembly
   • libz3.dll / libz3.so / libz3.dylib - Native library
4. Add Reference

   In your .NET project, add a reference to Microsoft.Z3.dll and ensure libz3.* is in the same directory as your executable or in the system PATH.

Option 3: Build from Source

Build Z3 with .NET bindings enabled:

Linux/macOS

git clone https://github.com/Z3Prover/z3.git
cd z3
python scripts/mk_make.py --dotnet
cd build
make

The .NET bindings will be in the build directory.

Visual Studio Setup

New Project with NuGet

1. Create Project

   Create a new C# Console Application or any .NET project type.

2. Install NuGet Package

   Right-click project → Manage NuGet Packages → Search for “Microsoft.Z3” → Install.

3. Start Coding

   Add using Microsoft.Z3; and start using Z3!

Manual Reference (Without NuGet)

1. Add Assembly Reference

   Right-click project → Add → Reference → Browse → Select Microsoft.Z3.dll.

2. Copy Native Library

   Copy libz3.dll (Windows) / libz3.so (Linux) / libz3.dylib (macOS) to your project’s output directory (usually bin\Debug or bin\Release).

   Or set it to copy automatically:

   • Add libz3.dll to project
   • Properties → Copy to Output Directory → Copy if newer

.NET Core / .NET 5+ CLI

Create New Project

# Create new console app
dotnet new console -n MyZ3App
cd MyZ3App

# Add Z3 package
dotnet add package Microsoft.Z3

# Build and run
dotnet build
dotnet run

Project File Example

MyZ3App.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Z3" Version="4.12.0" />
  </ItemGroup>
</Project>

Verify Installation

Create a test file:

Program.cs

using System;
using Microsoft.Z3;

class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine("Creating Z3 context...");
        
        using (Context ctx = new Context())
        {
            Console.WriteLine($"Z3 version: {ctx.Version}");
            Console.WriteLine($"Full version: {Microsoft.Z3.Version.ToString()}");
            
            // Simple test: x > 0
            IntExpr x = ctx.MkIntConst("x");
            Solver solver = ctx.MkSolver();
            solver.Assert(ctx.MkGt(x, ctx.MkInt(0)));
            
            if (solver.Check() == Status.SATISFIABLE)
            {
                Console.WriteLine("SAT");
                Console.WriteLine($"Model: {solver.Model}");
            }
            
            Console.WriteLine("Success!");
        }
    }
}

Build and run:

.NET CLI

dotnet build
dotnet run

Expected output:

Creating Z3 context...
Z3 version: 4.x.x.x
Full version: 4.x.x.x
SAT
Model: x -> 1
Success!

F# Setup

Z3 works seamlessly with F#:

Program.fs

open Microsoft.Z3
open System

[<EntryPoint>]
let main argv =
    use ctx = new Context()
    printfn "Z3 version: %s" (ctx.Version.ToString())
    
    // Simple test
    let x = ctx.MkIntConst("x")
    let solver = ctx.MkSolver()
    solver.Assert(ctx.MkGt(x, ctx.MkInt(0)))
    
    match solver.Check() with
    | Status.SATISFIABLE -> 
        printfn "SAT"
        printfn "Model: %O" solver.Model
    | Status.UNSATISFIABLE -> printfn "UNSAT"
    | _ -> printfn "UNKNOWN"
    
    0

Platform-Specific Notes

Windows

• Native library: libz3.dll
• The NuGet package automatically handles native dependencies
• For manual installation, ensure libz3.dll is in the same directory as your executable or in PATH

Linux

• Native library: libz3.so
• May need to install dependencies: sudo apt-get install libgomp1 (Ubuntu/Debian)
• Set LD_LIBRARY_PATH if needed: export LD_LIBRARY_PATH=/path/to/z3/lib:$LD_LIBRARY_PATH

macOS

• Native library: libz3.dylib
• Set DYLD_LIBRARY_PATH if needed: export DYLD_LIBRARY_PATH=/path/to/z3/lib:$DYLD_LIBRARY_PATH

Troubleshooting

FileNotFoundException: Microsoft.Z3.dll

Problem: Cannot find the managed assembly.

Solution:

• Reinstall the NuGet package
• If using manual reference, verify the path to Microsoft.Z3.dll
• Check that the assembly is being copied to the output directory

DllNotFoundException: libz3

Problem: Cannot load the native library.

Solution:

• Windows: Ensure libz3.dll is in the same folder as your exe or in PATH
• Linux: Install required dependencies, set LD_LIBRARY_PATH
• macOS: Set DYLD_LIBRARY_PATH
• If using NuGet, try cleaning and rebuilding: dotnet clean && dotnet build

BadImageFormatException

Problem: Architecture mismatch (32-bit vs 64-bit).

Solution:

• Ensure your application target matches the Z3 binary architecture
• Most Z3 distributions are 64-bit; set your project to x64:
  • Project Properties → Build → Platform target → x64
  • Or in .csproj: <PlatformTarget>x64</PlatformTarget>

TypeLoadException

Problem: Version mismatch between managed and native libraries.

Solution:

• Ensure Microsoft.Z3.dll and libz3.* are from the same Z3 version
• Reinstall the NuGet package

NuGet Package Details

The official NuGet package:

• Package ID: Microsoft.Z3
• Homepage: https://www.nuget.org/packages/Microsoft.Z3/
• Repository: https://github.com/Z3Prover/z3
• License: MIT

The package includes:

• Microsoft.Z3.dll - Managed .NET assembly
• Native libraries for Windows (x64, x86, ARM64)
• Native libraries for Linux (x64, ARM64)
• Native libraries for macOS (x64, ARM64)

Multi-Targeting

For libraries that target multiple frameworks:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFrameworks>net6.0;net48;netstandard2.0</TargetFrameworks>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Z3" Version="4.12.0" />
  </ItemGroup>
</Project>

Next Steps

Getting Started

Learn the basics of the Z3 .NET API

API Reference

Explore the complete .NET API documentation

NuGet Package

View on NuGet.org