STE MCP installation - Symmetry Docs

This guide walks through installing and connecting the Symmetry Tax Engine (STE) MCP server in each supported client. For what the MCP can do and example prompts, see the STE MCP overview.

Prerequisites

Active STE license
One of the supported AI apps installed on your computer (see below)

Don’t have an AI app yet? Pick one to get started. All four options below are free to download. If you’re not sure which to choose, Claude Desktop is the easiest starting point for non-technical users. It installs like any desktop app and requires no command line. See a walkthrough.

Tool	Best for	Download
Claude Desktop	Easiest setup; no technical experience needed	claude.ai/download
Cursor	Users who work in or alongside code	cursor.com/downloads
Claude Code	Terminal-comfortable users	Install guide
Gemini CLI	Users already in the Google ecosystem	github.com/google-gemini/gemini-cli

Installation

Add one MCP server entry to your assistant. The first time you use a tool, your browser will open and prompt you to log in using your Symmetry Client Support Center credentials.

Cursor
Claude Code
Gemini CLI
Claude Desktop

Method A: Settings UI

Open Cursor Settings

Press Cmd+, (macOS) or Ctrl+, (Windows/Linux) to open Settings.

Add an MCP server

Click MCP in the left sidebar, then Add MCP Server.

Fill in the details

Name: ste
URL: https://mcp.symmetry.com/ste
Leave Transport on the default (Streamable HTTP)

Save

The server will appear with a green dot once Cursor connects successfully.

Method B: Edit ~/.cursor/mcp.jsonIf the file doesn’t exist yet, create it. Add:

{
  "mcpServers": {
    "ste": {
      "url": "https://mcp.symmetry.com/ste"
    }
  }
}

If you already have other MCP servers configured, add ste as a new key inside the existing mcpServers object—don’t replace the whole file! For example, a file with two servers looks like:

{
  "mcpServers": {
    "some-other-server": {
      "url": "https://example.com/mcp"
    },
    "ste": {
      "url": "https://mcp.symmetry.com/ste"
    }
  }
}

Save the file. Cursor picks up the change automatically; no restart needed.

Run this command in your terminal:

claude mcp add ste --transport http https://mcp.symmetry.com/ste --callback-port 33418

Restart Claude Code after running the command. Claude Code only loads MCPs at startup—exit your current session and open a new one.

To verify, run:

claude mcp list

You should see ste in the output.Why --callback-port 33418? Symmetry’s OAuth allowlist only accepts port 33418 as a redirect target. Claude Code picks a random ephemeral port by default, which causes a redirect_mismatch error. Pinning the port fixes this. Cursor uses 33418 by default, so no flag is needed there.

Edit ~/.gemini/settings.json and add the following under mcpServers:

{
  "mcpServers": {
    "ste-mcp": {
      "httpUrl": "https://mcp.symmetry.com/ste",
      "oauth": {
        "enabled": true,
        "redirectUri": "http://localhost:33418/oauth/callback"
      }
    }
  }
}

Always set redirectUri explicitly. If omitted, Gemini CLI may choose a random port that fails authentication.

Open Customize

Open Customize from the left sidebar on the home screen.

Open Connectors

Select the Connectors tab on the left.

Add a custom connector

Click the + button (next to the search icon) at the top of the Connectors panel, then choose Add custom connector.

Fill in the details

Name: ste
URL: https://mcp.symmetry.com/ste
Leave the OAuth Client ID and OAuth Client Secret fields blank — they’re optional and not needed here. Click Add.

Connect

The ste connector now appears under Not connected, tagged CUSTOM. Select it, then click Connect.

Authenticate

Your browser will open and prompt you to log in using your Symmetry Client Support Center credentials.

Verify

Start a new chat and ask:

use the ste mcp to get the ste version

Verify the response looks like the following:

The STE deployment reports:
STE version: 2026.6.2
Release: 1.173.2127 (major 1, minor 173, revision 2127)

Prefer to watch it done first? See Connect Claude Desktop to the STE MCP Demo.

Verify the connection

The easiest test is ste_get_version. It confirms auth, transport, and the STE engine are all working. In any supported client, ask:

use the ste mcp to get the ste version

The first time, your browser will open for Symmetry sign-in. After authenticating using your Client Support Center credentials, the client will display a version string like 2026.4.3.7-SNAPSHOT. Subsequent calls in the same session reuse the cached token—no more browser prompts.

Next steps

New to what the MCP can do? See the STE MCP overview for the full tool list and sample prompts.
Prefer a video walkthrough for Claude Desktop? See Connect Claude Desktop to the STE MCP Demo.
Running into issues? See STE MCP Troubleshooting.

​Prerequisites

​Installation

​Verify the connection

​Next steps

Prerequisites

Installation

Verify the connection

Next steps