Horizen IT Services
Get started · Microsoft 365

Put your AI assistant to work inside the Microsoft 365 you already own.

Sign in with your work account and we'll connect your assistant to your company's Microsoft 365 — securely, in about a minute. A person on your team still approves everything.

1 Sign in to begin

Use the work account you already have — nothing new to create. Microsoft or Google signs you in, so we never see or store your password.

Secure sign-in. Your password stays with Microsoft or Google — we never see it.

2 Your connection to Cortex

This provider-independent MCP endpoint connects your AI assistant to Cortex, the Horizen IT Services gateway. Add it to the assistant you use; the destination and your assigned permissions stay the same.

https://mcp.horizenitservices.com/mcp

Access is granted only by OAuth sign-in when your assistant asks for it. The URL holds no secret: never add a token to it, and never paste a credential into a chat.

3 Download Shellphone MCP

The same door, on your own machine. One file, no installer. Pick your system:

It runs as a local MCP server for desktop assistants: command shellphone-mcp serve --stdio. Your administrator supplies its access credential.

4 Connect to Cortex from your assistant

Use the provider-independent endpoint from step 2. Add it as a remote MCP connector and sign in when prompted.

Claude (Anthropic)

  1. On Claude’s website, open Customize → Connectors, then + → Add custom connector.
  2. Name it MythOS MCP and enter the endpoint URL from step 2. Sign in when Claude prompts you.
  3. Add the connector, review the available tools and requested permissions, then enable it from the conversation’s connector menu.

Managed Claude workspaces may require an owner to configure connectors. Claude’s current setup guide

ChatGPT (OpenAI)

  1. Open Plugins in ChatGPT, select +, then Add custom MCP server. Account and workspace policies decide whether you can add one.
  2. Enter the name MythOS MCP and a short description. Under Connection, choose the public endpoint option and enter the same endpoint URL from step 2.
  3. For authentication, choose OAuth and complete the sign-in. Review the risk warning, then select I understand and want to continue.
  4. Select Create as a plugin and review the discovered tools and requested permissions. Install the plugin, start a new conversation, type @, and select it.

Menus and availability depend on your account and workspace policy. OpenAI’s current setup guide

If setup fails, send the error text to info@mythcast.net.