STE MCP overview

The Symmetry Tax Engine Model Context Protocol (MCP) server gives you direct access to STE’s payroll tax calculation engine through plain English, inside the AI tools you already use. No code. No developer ticket. No payload to assemble. Supported clients: Claude Desktop, Claude Code, Cursor, ChatGPT (paid plans only), or other AI-enabled IDEs

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Who is this for?

• Tax and compliance analysts: validating jurisdiction rules and rate changes before they go to production
• Customer support reps: answering “why did my paycheck calculate this way?” without waiting on engineering
• Implementation and onboarding teams: running parallel-payroll sanity checks during cutover
• Payroll operations leads: verifying that an address maps to the correct locals
• Product managers: prototyping a new wage-type, benefit, or election before writing a ticket

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Get started

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What you can ask

26 tools sit behind the server, covering payroll tax calculation and gross-up, rate history, wage bases, bracket schedules, benefit taxability, jurisdiction lookup, and the tax law changes Symmetry is tracking (Tax Radar). You never need to call them by name. Describe what you need in plain English and your assistant picks the right one.

Calculate semi-monthly payroll taxes for a $3,000 regular wage in Pittsburgh, PA. Single, no dependents.

How has the federal Social Security rate moved over time?

PSD code 450106 came in on a client file. What place is that, and which taxes sit behind it?

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Beyond tools

The server offers two more things alongside its tools.

• Resources: six reference documents your assistant can look up so it reads rates, wage bases, and counts correctly.
• Prompts: seven saved procedures you start yourself, such as comparing two releases or explaining a difference of under a dollar.

Prompts are different from sample prompts. A sample prompt is a question you type in plain English. A prompt is a built-in procedure that calls several tools in a set order.