Visual Studio Code

Connect Visual Studio Code (Github Copilot) to Ternary.

Before you start

You need:

An existing Ternary account
Access to at least one Ternary tenant
VS Code 1.106 or later
GitHub Copilot with Agent mode

Earlier VS Code versions may not support the sign-in method Ternary uses without additional manual configuration.

⚠️
On Copilot Business or Enterprise plans, an administrator may need to enable MCP servers in your organization's Copilot policy.

Step 1: Add the server

Open the Command Palette:
- macOS: Cmd + Shift + P
- Windows/Linux: Ctrl + Shift + P
Run MCP: Add Server.
Choose HTTP.

When VS Code asks for the server URL, paste the URL for your Ternary region:

https://core-api.ternary.app/mcp

Then name the server ternary, and choose whether to save it in the current workspace or in your user profile for all workspaces.

After you finish, VS Code writes a file like this (workspace example):

{
  "servers": {
    "ternary": {
      "type": "http",
      "url": "https://core-api.ternary.app/mcp"
    }
  }
}

You can create that file yourself instead of using the Command Palette. For this workspace, put it in .vscode/mcp.json. For all workspaces, use your user MCP configuration.

If the file already has other servers, add the "ternary" block inside "servers". Do not replace the rest of the file.

Step 2: Sign in

Open the Command Palette.
Run MCP: List Servers.
Select ternary.
Select Start Server.

VS Code opens Ternary in your browser.

Sign in with your normal Ternary credentials and approve access. When authentication completes, MCP: List Servers should show Ternary as running. The sign-in is remembered for normal day-to-day use.

Step 3: Use Ternary in Copilot

Open Copilot Chat.
Switch to Agent mode.
Open the tools selector.
Confirm that Ternary tools are enabled.

Then ask:

Using Ternary, what did we spend last month by provider?

Show our top five services by spend.

Which budgets are at risk?

List recent cost alerts.

The first time Copilot uses a Ternary tool, VS Code may ask for permission.

Ternary's MCP is predominantly read-only. Creating a private report is the one current write action and should only happen when you explicitly request it.

Troubleshooting

Ternary does not appear in Copilot

Check:

The MCP server is running
You are using Copilot Agent mode
Ternary tools are enabled
Your organization allows MCP servers

MCP features can be missing entirely if your organization's GitHub Copilot policy disables them. Ask your Copilot administrator to enable MCP servers in Copilot.

VS Code refuses to add the server

Your organization may restrict which MCP servers are allowed, through the chat.mcp.access policy or an allowlist.

If that policy is set to registry, Ternary has to be published in your organization's MCP registry before VS Code will load it. Your IT team owns both settings.

VS Code asks for a client ID

You are likely on a version older than 1.106. Versions 1.102 to 1.105 can support MCP but may require a client ID by hand for the authentication flow Ternary uses.

Cancel the dialog and run Code → Check for Updates. Do not enter a client ID.

Sign-in fails

Confirm that you used the correct regional Ternary URL, with no trailing slash.

No tenants appear

Ask your Ternary administrator to confirm your explicit tenant access.

The agent ignores Ternary

Check that the tools icon shows Ternary tools enabled, make sure the mode is Agent and not Ask, and name Ternary in the question.

See Troubleshooting Ternary MCP for shared issues.