Tax Logic API

Tax Logic API (TLA) converts Symmetry Tax Engine (STE) payroll calculations into simplified, employee-facing explanations.

It is designed to:

• Explain why specific taxes were withheld
• Provide plain-language reasoning for calculation results
• Break down taxable wages

Tax Logic AI does not calculate taxes. It explains calculations already performed by STE.

Integration in Three Easy Steps

A payroll calculation is performed in STE.

1. Your application retains the STE payroll calculation log or JSON request (the payroll context)
2. You send that data to the TLA API
3. The API returns a structured explanation and you display in your UI

The API supports two integration paths:

• STE-Hosted (JSON integration): Send payroll context directly in the request.
• On-Prem STE: Use STE session recording to capture calculation context before calling TLA.

Before You Begin

Download the Developer Integration Kit

The Developer Integration Kit includes documentation, sample code, a Postman collection, and an AI IDE copilot that works with Cursor and other AI-assisted IDEs.

Download the ZIP file from the Client Support Center, open it in your IDE, and provide your API key. The included copilot can then guide you through authentication, request construction, and response validation step by step.

This allows you to stand up and test a working integration in minutes using the provided samples and tools.

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See It Integrated in 5 Minutes!

Clients can watch a complete, end-to-end TLA API integration built in approximately five minutes using GitHub Copilot in our Client Support Center. The demo walks through authentication, request construction, and returning tax explanations in a working application.

Reach out to us if you're interested in learning more about Tax Logic API.

Prerequisites

• Symmetry API Key — Your API key
• STE Integration — Your system already uses the Symmetry Tax Engine for payroll tax calculations
• Postman (optional) — For testing with the provided collection