ChatGPT

Set up Ternary MCP in ChatGPT.

Connect ChatGPT to Ternary to ask questions about your live technology-spend data in a regular conversation.

Use this setup when you want ChatGPT to run cost queries, review budgets, inspect dashboards, retrieve cost alerts, work with reports, review savings recommendations, or weigh AI spend against revenue.

For OpenAI Codex, use the separate Codex setup guide.

Before you start

You need:

An existing Ternary account
Access to at least one Ternary tenant
Developer mode enabled in ChatGPT

⚠️
Developer mode
On Business, Enterprise, or Edu workspaces, an administrator may need to allow Developer mode and custom plugins.

You can add the Ternary plugin from ChatGPT on web or desktop. Once it is on your ChatGPT account, you can also use it from supported ChatGPT clients where you are signed in. The mobile apps can use a plugin you have already added. Adding one must happen on web or desktop.

ChatGPT modes

Ternary behaves differently depending on the ChatGPT mode you use.

Mode	Ternary access
Regular chat with Developer mode	Full Ternary MCP tool set
Deep research	`search` and `fetch` only

Deep research can find and retrieve supported Ternary content such as tenants and saved reports. It cannot run the full set of ad-hoc Ternary analysis tools.

For cost analysis, budgets, dashboards, alerts, recommendations, and AI ROI, use a regular chat with the Ternary plugin enabled.

Step 1: Enable Developer mode

Open ChatGPT Settings.
Go to Security and login.
Find Developer mode and turn it on.

You can also use the Developer mode shortcut at the bottom of Settings → Plugins. ChatGPT displays an elevated-risk warning because Developer mode allows custom MCP servers. This is expected.

Step 2: Add Ternary

Open Plugins from the ChatGPT sidebar.
Select Create app.
Fill in the New Plugin dialog as shown below.
Confirm that you understand you are adding a custom server.
Select Create.

Name
Ternary

Connection
Choose Server URL and enter the URL for your Ternary region:

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

Authentication
Keep OAuth selected. Leave advanced OAuth settings unchanged. ChatGPT discovers them automatically.

🚧
Use the URL exactly
Include /mcp and do not add a trailing slash.

Step 3: Sign in to Ternary

After creating the plugin, ChatGPT opens an Add Ternary to ChatGPT dialog.

Select Sign in with Ternary.
Sign in with your normal Ternary credentials.
Approve the access request.

Your Ternary user must already exist in the region you selected. Connecting MCP does not create a Ternary account. The plugin's detail page then shows as connected.

Step 4: Use Ternary in a chat

Start a new regular chat, select the + button in the composer and choose Ternary to make the plugin available for the message.

Then ask:

What did we spend last month, grouped by provider?

Which budgets are currently at risk or over budget?

What changed on our Executive dashboard compared with the previous period?

Which cost alerts fired in the last 30 days?

You can also mention Ternary directly:

Using Ternary, show our top five services by spend for last month.

Reading tools typically run without extra confirmation under ChatGPT's default Allow low-risk actions setting. Creating a report writes data, so ChatGPT asks before it runs.

Permissions and writes

Every Ternary MCP request runs with your existing Ternary permissions.

Most current capabilities read data. Ternary can also create a private report when you explicitly ask ChatGPT to save an analysis.

It cannot create or edit budgets, labels, rules, or other Ternary objects.

Refresh Ternary when new capabilities are added

ChatGPT copies the Ternary MCP tool definitions when you create the plugin. It does not refresh them automatically when Ternary changes.

Your plugin may be out of date if:

Ternary documentation describes a capability ChatGPT cannot find
ChatGPT reports fewer Ternary capabilities than expected
A newly released Ternary MCP capability does not appear

To refresh:

Open Settings → Plugins.
Select Ternary.
Find Information.
Select Refresh.
Start a new chat.

An existing conversation keeps the tool definitions it started with. If Refresh fails with a reauthentication error, or the tool list does not change, remove the Ternary plugin and add it again. Reconnecting authentication is not the same as refreshing the tool definitions.

Troubleshooting

I don't see Create app

Developer mode is probably off.

Go to Settings → Security and login → Developer mode and enable it.

Plugin creation fails

Check:

The URL includes /mcp
There is no trailing slash
You selected the correct Ternary region

Then retry. A first attempt can time out while the service warms up.

Sign-in fails

Your email must belong to an existing Ternary user in the selected region.

US and EU accounts are separate.

No tenants appear

Your Ternary user may not have an explicit role on a tenant.

Ask your Ternary administrator to grant access to the tenants you need.

Only search and fetch are available

You are likely using Deep research.

Start a regular chat with the Ternary plugin enabled.

A documented Ternary capability is missing

Refresh the plugin under Settings → Plugins → Ternary, then start a new chat.

If Refresh fails, delete the plugin and create it again. Reconnect only signs you in again. It does not necessarily refresh the tool list.

See Troubleshooting Ternary MCP for shared connection issues.