.NET SDK quickstart - Symmetry Docs

The .NET SDK is a managed assembly that wraps the native STE library via P/Invoke. It exposes STEPayrollCalculator in the Symmetry.TaxEngine namespace, mirroring the Java SDK method-for-method. This quickstart runs a federal + California state calculation for one employee using the modern STE2-style configuration.

STE2-style configures every tax through setJurisdictionData(...) + setJurisdictionMiscellaneousParms(...) using a uniqueTaxID. Prefer it over the legacy per-tax setters. (The shipped HelloPayrollWorld sample still uses STE1-style calls — use this page as the STE2 template instead.)

Prerequisites

Get the SDK and tax database

You need the STE .NET assembly, the native library for your platform (ste.dll / libste.so / libste.dylib), and an STE home directory containing the tax database. These come with your STE license.

Put the native library on the load path

On Windows, keep ste.dll on PATH or alongside your executable. See Linking the native library for other platforms.

Calculate

using System;
using Symmetry.TaxEngine;

class HelloPayroll
{
    static void Main()
    {
        // 1. Initialize the engine against your STE home directory.
        STEPayrollCalculator ste = new STEPayrollCalculator(@"C:\Program Files\Symmetry Tax Engine\");

        try
        {
            // 2. Start clean for this employee.
            ste.clearPayrollCalculations();
            ste.clearSettings();

            // 3. Describe the pay run: biweekly, 12th period of the year.
            ste.setPayrollRunParameters(new DateTime(2026, 6, 15), 26, 12);

            string federalLoc = "00-000-0000";
            string stateLoc   = "06-000-0000";              // California
            string fitTaxId   = "00-000-0000-FIT-000";      // Federal income tax
            string sitTaxId   = "06-000-0000-SIT-000";      // California SIT
            Money zero = Money.zero();
            Rate  zeroRate = new Rate(0D);

            // 4. Wages: $4,000 gross, 80 hours, at both the federal and state locations.
            ste.setCalculationMethod(federalLoc, CalcMethod.ANNUALIZED, CalcMethod.NONE);
            ste.setCalculationMethod(stateLoc,   CalcMethod.ANNUALIZED, CalcMethod.NONE);
            ste.setWages(federalLoc, WageType.REGULAR, new Hours(80D), new Money(4000D), zero, zero, zero);
            ste.setWages(stateLoc,   WageType.REGULAR, new Hours(80D), new Money(4000D), zero, zero, zero);

            // 5. Federal income tax (STE2): jurisdiction + withholding elections.
            ste.setJurisdictionData(fitTaxId, federalLoc, false, true,
                zero, zero, zero, zero, zero,
                JurisdictionRounding.DEFAULT, false, false,
                zeroRate, zero, zeroRate, zero);
            ste.setJurisdictionMiscellaneousParms(fitTaxId, "FILINGSTATUS", "S");
            ste.setJurisdictionMiscellaneousParms(fitTaxId, "TOTALALLOWANCES", 0);

            // 6. California SIT (STE2).
            ste.setJurisdictionData(sitTaxId, stateLoc, false, true,
                zero, zero, zero, zero, zero,
                JurisdictionRounding.DEFAULT, false, false,
                zeroRate, zero, zeroRate, zero);
            ste.setJurisdictionMiscellaneousParms(sitTaxId, "FILINGSTATUS", "S");
            ste.setJurisdictionMiscellaneousParms(sitTaxId, "TOTALALLOWANCES", "0");

            // 7. Calculate.
            ste.calculateTaxes();

            // 8. Read the withholding per tax.
            Money fit = ste.getJurisdictionCalculation(fitTaxId, WageType.REGULAR).tax;
            Money sit = ste.getJurisdictionCalculation(sitTaxId, WageType.REGULAR).tax;
            Console.WriteLine($"Federal income tax: {fit}");
            Console.WriteLine($"California SIT:     {sit}");
        }
        finally
        {
            // 9. Release native resources.
            ste.Dispose();
        }
    }
}

What each step does

Step	Call	Purpose
Init	`new STEPayrollCalculator(steHome)`	Opens an engine handle against the tax database.
Reset	`clearPayrollCalculations()`, `clearSettings()`	Clears prior state so the handle is reusable.
Pay run	`setPayrollRunParameters(date, ppy, period)`	Pay date, periods per year, and current period.
Wages	`setCalculationMethod(...)`, `setWages(...)`	Method (Annualized/Flat) and gross/hours by location.
Jurisdiction	`setJurisdictionData(uniqueTaxID, …)`	Configures one tax; residency, rounding, overrides.
Elections	`setJurisdictionMiscellaneousParms(uniqueTaxID, name, value)`	Filing status, allowances, and other W-4-style inputs.
Calculate	`calculateTaxes()`	Runs the employee pass.
Read	`getJurisdictionCalculation(uniqueTaxID, wageType).tax`	The amount to withhold for that tax.

The .NET surface matches Java closely; the main differences are System.DateTime instead of java.util.Date, Dispose() instead of close(), and .tax (struct field) instead of .getTax().

Handles, threads, and pooling

A handle is not thread-safe — use one per thread. For high volume, reuse handles with STEObjectPool (checkOut() / checkIn()) rather than constructing one per calculation. See Handles & pooling.

Next steps

Full calculation walkthrough

Install the interface and run a complete, realistic pay calc end to end.

Configuring a calculation

Wages, jurisdictions, benefits, and engine options in depth.

Migrating from STE1-style

Map legacy per-tax setters onto STE2-style calls.

​Prerequisites

​Calculate

​What each step does

​Handles, threads, and pooling

​Next steps

Full calculation walkthrough

Configuring a calculation

Migrating from STE1-style

Prerequisites

Calculate

What each step does

Handles, threads, and pooling

Next steps