MCP for AI assistants - Cedar.AI Documentation

The MCP page in Data Depot shows you how to connect an AI assistant to Cedar ARMS through the Model Context Protocol (MCP). Once connected, you can ask the assistant questions such as “How many loaded cars are at Quillmoor Junction?” and it looks up the answer in ARMS for you.

Uses your own login. You sign in with your Cedar account when the assistant first connects. There is no separate key to create or share.
Read-only. The assistant can list and look up ARMS data. It can’t create, update, move, or delete anything; those changes stay in the ARMS app.
Your permissions apply. The assistant can see only what you can see in ARMS, for the carriers you have access to.

Connect MCP page with the starter prompt summary, Copy starter prompt, See what it can do, and the ChatGPT card — The Connect tab, with the starter prompt and setup for each AI app

Connect your AI app

Using ChatGPT? Cedar is listed in the ChatGPT plugin directory as CedarAI Data Depot. Install it there and sign in with Cedar. There’s nothing to copy or paste. See the ChatGPT tab below.

Every other app connects to the same server URL:

https://mcp.arms.cedarai.com/mcp

Open MCP in the sidebar and find your app on the Connect tab.⁠‌‌‌‌‌‌‌‌‌‌⁠ Each card has the steps for that app and a Copy button for each configuration or command. After you add the server, your app opens a Cedar sign-in page; sign in to finish connecting.

Connect your AI app section with the ChatGPT, OpenAI Codex, Claude Desktop & Claude Code, Cursor, and Microsoft Copilot Studio cards — Setup cards for each supported app

Cedar is listed in the ChatGPT plugin directory as CedarAI Data Depot.

Select Open in ChatGPT on the ChatGPT card in Data Depot, or open the CedarAI Data Depot listing directly.
Select Install plugin, then complete Cedar sign-in when prompted.
In any chat, type @CedarAI Data Depot followed by your question, for example “@CedarAI Data Depot How many loaded cars are at Quillmoor Junction?”

If your company uses a ChatGPT Business or Enterprise workspace, a workspace admin may need to allow the plugin first.

Add this to ~/.codex/config.toml (shared by the Codex CLI and IDE extension):

[mcp_servers.arms]
url = "https://mcp.arms.cedarai.com/mcp"

Or run:

codex mcp add arms --url https://mcp.arms.cedarai.com/mcp

Then complete Cedar sign-in when prompted.

Claude Desktop: paste this into your MCP or Connectors settings:

{
  "mcpServers": {
    "arms": {
      "url": "https://mcp.arms.cedarai.com/mcp"
    }
  }
}

Claude Code: run:

claude mcp add arms --transport http https://mcp.arms.cedarai.com/mcp

Complete Cedar sign-in when prompted.

Select Add to Cursor on the Cursor card in Data Depot. Cursor asks to install an MCP server named arms. Approve it, then sign in with Cedar in your browser. You can also copy the configuration under Or paste into Cursor’s MCP settings on the card, the same JSON shown for Claude Desktop, into Cursor’s MCP settings.

This is Microsoft Copilot Studio, not GitHub Copilot. In Copilot Studio:

Open your agent, then go to Tools → Add a tool → Model Context Protocol.
For the server name, enter Cedar ARMS.
For the server description, copy the Server description from the card. It tells the agent that Cedar gives read-only access to ARMS rail data, so the agent knows when to use it.
Paste the server URL. For authentication, choose OAuth 2.0, then Dynamic discovery.
Create a connection and complete Cedar sign-in when prompted.

For GitHub Copilot in VS Code, create or open .vscode/mcp.json (or run MCP: Open User Configuration from the Command Palette) and paste:

{
  "servers": {
    "arms": {
      "type": "http",
      "url": "https://mcp.arms.cedarai.com/mcp"
    }
  }
}

Save, then sign in with Cedar when VS Code asks.

Start with the starter prompt

Select Copy starter prompt and paste it into a new chat after you connect. It tells the assistant how to use Cedar correctly. The Start here after you connect panel sums it up:

check which carriers you can access before looking anything up;
name the carrier by its reporting mark, and never guess one;
say so when access is denied instead of making up data;
page through large results, such as railcar inventory, instead of asking for everything at once.

Select Show full prompt to read the whole prompt before you copy it. The same guide is available inside the connection, so the assistant can look it up on its own. See what it can do opens the Permissions tab.

See what your assistant can do

The Permissions tab lists the read-only actions an assistant can take for the selected carrier, based on the user groups’ ARMS permissions.⁠‌‌‌‌‌‌‌‌‌‌⁠ Different people can see different actions.

Permissions tab with the User groups filter, the MCP actions count, the API families, and the Railcar actions — The Permissions tab lists MCP actions by API family

Use User groups to see the actions available to one or more groups. The count on the right shows how many MCP actions that adds up to.
Actions are grouped by API family. Each one shows its method and path, with a Docs link to the API reference.
Other ARMS actions, at the bottom, shows how many API operations your assistant can’t use, because they change data. Open it to see them. Do those in the ARMS app.

This tab only shows existing access. It doesn’t grant anything. To change what someone can do, change their ARMS roles in the Admin Portal.

The MCP pages don’t need a Data Depot role, and the carrier list on these pages includes every carrier you can access. To protect privacy, Cedar leaves some details out of what it returns to the assistant, such as street addresses, email addresses, and phone numbers. See MCP data handling.

Troubleshooting

The assistant says I'm not authorized

The assistant can only do what your ARMS permissions allow for that carrier.⁠‌‌‌‌‌‌‌‌‌‌⁠ Check the Permissions tab, and ask your administrator if you need more access.

The assistant asks which carrier I mean

If you can access more than one carrier, name the carrier by its reporting mark in your question, for example “Show inventory for DEMO”.

The assistant offers to change data

This connection is read-only. Make changes in the ARMS app.

The Permissions tab shows this when your login doesn’t belong to any carrier in ARMS. Your assistant can only see data for carriers you belong to. Ask your carrier’s ARMS administrator to add you to an ARMS user group, then reload the page. If you’re not sure who that is, contact your Cedar account team.

I don't see MCP in the sidebar

MCP may not be turned on for your account yet. Contact your Cedar account team.

​Connect your AI app

​Start with the starter prompt

​See what your assistant can do

​Troubleshooting

​Related pages

Connect your AI app

Start with the starter prompt

See what your assistant can do

Troubleshooting

Related pages