This page covers the operating systems, architectures, and languages supported by the locally installed On-Premise version of the Symmetry Tax Engine (STE), along with sizing guidance. (The hosted Web API has no local requirements — you only need an HTTPS client.)
Supported languages
The On-Premise SDK ships with native interfaces for:
Java requires a Java Development Kit (JDK), version 11 or later.
For .NET, the distribution includes interface assemblies for several targets so you can match your existing runtime:
For new .NET integrations, target .NET 8 (or consume the .NET Standard 2.0 assembly if you’re still on .NET Framework 4.6.1–4.8). The .NET Framework 2.0 / 4.0 and .NET Standard 1.1 assemblies remain in the distribution for existing integrations only.
Operating systems and architectures
The On-Premise STE runs on Windows, Linux (and other UNIX), and macOS, on both x64 (AMD64) and ARM64 architectures. On Windows, both 64-bit and legacy 32-bit builds are available. (Running Windows on ARM is supported unofficially.) The engine’s shared libraries (ste-shared-libraries) must be made available to your application on any platform:
Windows
Linux / UNIX
macOS
Append the path to your ste-shared-libraries folder to the system Path environment variable (under Advanced System Settings > Environment Variables > System Variables), or copy the library files directly into your project’s build output. Depending on which build you use, you will need the matching Visual Studio redistributable (2010, 2013, or 2022) installed.Both 64-bit and 32-bit builds are available. When targeting .NET Framework 4.5 or higher with the 64-bit engine, make sure Prefer 32-bit is unchecked in your project’s build settings.
The shared object (.so) files are usually placed in /usr/local/lib. To make them available to your application, add the path to your ste-shared-libraries folder to the LD_LIBRARY_PATH environment variable.
The engine ships as a universal shared library (.dylib) that runs on both Apple Silicon (ARM64) and Intel (x64) Macs. Make the ste-shared-libraries folder available to your application via DYLD_LIBRARY_PATH, or copy the library into your build output.
Regardless of platform, an installation consists of the ste-interface-files, ste-root, and ste-shared-libraries folders plus versions.json, and a valid ste-license.dat file must be present in ste-root.
- Tax database: 29.9 MB
- Engine binary: 4.1 MB
The entire STE Win64 component — with all interface files and some helper DLLs — is about 32.5 MB.
Sizing your environment
Symmetry does not publish fixed CPU, memory, or disk requirements for the On-Premise STE. Because the engine is so lightweight, hardware is rarely the constraint — appropriate sizing depends on your own workload (how many pay calculations you run in parallel and how you architect your application) far more than on the engine itself.
Size your machine (or machines, in an n-tier architecture) for the amount of parallel processing your workload requires. If you’d like guidance for a specific deployment, contact Symmetry.
Concurrency and scaling
The STE is built for high-volume, parallel payroll. In a multi-threaded environment, multiple engine instances can be checked out of a built-in pool, used, and returned for reuse by other threads without re-initializing. Initialization takes only milliseconds, but across thousands or tens of thousands of pay calculations that savings adds up. 
