> ## Documentation Index
> Fetch the complete documentation index at: https://docs.symmetry.com/llms.txt
> Use this file to discover all available pages before exploring further.

# AI interfaces overview

> The STE MCP and Symmetry Tax Logic — conversational calculation and AI log analysis layered on the engine.

Beyond the programmatic [SDK](/ste/quickstarts/java-sdk-quickstart) and [hosted API](/ste/quickstarts/hosted-api-quickstart), the STE offers AI-powered interfaces. They don't replace your production integration — they sit alongside it, for building agent experiences and for understanding what a calculation did.

## Everything runs on the same core

Both AI interfaces sit on the **same calculation engine and tax database** as the SDK and hosted API. The MCP calls Symmetry's hosted engine; Tax Logic reads the logs the engine produces. Results and explanations are consistent with what your production integration computes.

## Licensing

<Warning>
  All AI interfaces require an **STE license**.

  * **STE MCP** is hosted by Symmetry, so a license is all you need to start chatting — connect your client to the remote service over OAuth, with no separate running instance to operate.
  * **Symmetry Tax Logic** additionally requires a **running STE** (hosted or on-premise) to produce the log files it analyzes.

  See [Licensing](/ste/overview/licensing) for how the STE license, hosted API key, and SLS API key relate.
</Warning>

## The three AI interfaces

<CardGroup cols={3}>
  <Card title="STE MCP" icon="plug" href="/ste/ai-interfaces/mcp-overview">
    A Model Context Protocol server that gives you direct access to STE's calculation engine through plain English, inside the AI tools you already use (Cursor, Claude Desktop, Claude Code, Gemini CLI). No code, no payload to assemble.
  </Card>

  <Card title="Tax Logic Chat" icon="comments" href="/ste/ai-interfaces/tax-logic-chat">
    An AI-powered agent that explains how STE calculated a specific tax. Upload a log file or JSON payload, ask a question, and get a detailed, step-by-step explanation.
  </Card>

  <Card title="Tax Logic API" icon="code" href="/ste/ai-interfaces/tax-logic-api">
    A single API endpoint that turns complex tax computation logic into clear, plain-language explanations you can display to employees in self-service portals and payroll UIs.
  </Card>
</CardGroup>

## Which one is right for me?

<CardGroup cols={1}>
  <Card title="STE MCP" icon="plug">
    Best for tax and compliance analysts, support reps, implementation teams, and product managers who want to run calculations, resolve locations, and look up jurisdiction and benefit data conversationally — without writing code. Requires an active STE license and a supported AI client.
  </Card>

  <Card title="Symmetry Tax Logic Chat" icon="comments">
    Best for troubleshooting and understanding a specific calculation from a log file or payload. Available in the Client Support Center and included with Symmetry Tax Engine Premium.
  </Card>

  <Card title="Symmetry Tax Logic API" icon="code">
    Best for building transparent, employee-facing tax explanations into payroll platforms, HR systems, and self-service portals. Designed for integration in about a day using the Developer Integration Kit.
  </Card>
</CardGroup>

## Building an integration?

If you're a developer implementing or integrating with STE, the [STE Developer AI CoPilot](/ste/ai-interfaces/developer-ai-copilot) is an AI-assisted development resource you can load directly into an AI-powered IDE (Cursor, VS Code with GitHub Copilot, and more) for context-aware guidance, implementation planning, and code generation.