OpenCode

Connect OpenCode to Ternary by adding Ternary as a remote MCP server and authenticating through OAuth.

Before you start

You need:

• An existing Ternary account
• Access to at least one Ternary tenant
• OpenCode installed and configured

Step 1: Add Ternary

OpenCode reads MCP servers from an opencode.json file.

Use one of these locations:

• Every project: ~/.config/opencode/opencode.json in your home folder
• This project only: opencode.json in the project folder

Open that file in a text editor. If it does not exist yet, create it.

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

Paste the configuration for the region where your Ternary tenant is hosted:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "ternary": {
      "type": "remote",
      "url": "https://core-api.ternary.app/mcp",
      "oauth": {
        "clientId": "https://core-api.ternary.app/oauth/client-metadata.json"
      }
    }
  }
}

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "ternary": {
      "type": "remote",
      "url": "https://core-api.eu.ternary.app/mcp",
      "oauth": {
        "clientId": "https://core-api.ternary.app/oauth/client-metadata.json"
      }
    }
  }
}

Save the file. The client ID stays the same for US and EU. Do not add a client secret.

Step 2: Authenticate

Open a terminal. Paste this command and press Enter:

opencode mcp auth ternary

Run this in your shell, not as a message inside an OpenCode session. If OpenCode is already open, use a separate terminal window.

OpenCode starts the Ternary browser sign-in flow.

1. Sign in with your existing Ternary account.
2. Approve access.
3. Return to the terminal.

If the browser does not open, run the same command again. You can also start OpenCode and authenticate from /mcps.

To confirm Ternary is connected, run:

opencode mcp list

ternary should appear and show as authenticated.

Step 3: Ask a question

Try:

Using Ternary, show last month's spend by provider.

Which budgets need attention?

List recent cost alerts.

Troubleshooting

See Troubleshooting Ternary MCP for shared issues.