Background

This article describes how to connect Carbon Signal to your AI assistant to ask questions about your portfolio in plain language, such as "Which of my buildings have the highest EUI?" or "Show me the emissions timeline for 100 Main St." The Carbon Signal MCP server works with any assistant that supports remote MCP servers, including Claude and ChatGPT. You sign in with your normal Carbon Signal account, and the assistant can only see the teams and buildings you already have access to. For examples of how to interact with Carbon Signal using a chat interface, see Using Carbon Signal with Claude.

Connecting to Claude

Custom connectors are available on Claude's web app, desktop app, and Cowork on all plans. Free plans are limited to one custom connector. Pro and Max plans support additional connectors.

Free, Pro, and Max Plans
  1. In Claude, go to Customize → Connectors
  2. Click + Add, then Add custom connector
  3. Enter Carbon Signal as the name and https://api.carbonsignal.com/mcp as the URL. Click Continue.
  4. Under Authentication, select "Sign in now."
  5. Under OAuth client, select "Use Claude's published identity." Scroll down and click Add
  6. Click Connect when prompted, sign in with your Carbon Signal account credentials, and approve access.
Team and Enterprise Plans

For Team and Enterprise plans, an organization Owner needs to add the connector. Once added, it will be available for everyone connected to that account.

  1. Go to Organization settings → Connectors
  2. Click Add, hover over Custom, and select Web
  3. Enter the name Carbon Signal and the URL https://api.carbonsignal.com/mcp, then click Add.

Each member of the Claude account then goes to Customize → Connectors, finds Carbon Signal, and clicks Connect to sign in with their own Carbon Signal account credentials.

Using it in a Chat

Click the + button in the lower left of the chat box, choose Connectors, and make sure Carbon Signal is turned on. For more help setting up a connector within Claude, see Get started with custom connectors using remote MCP.

Connecting to ChatGPT

In ChatGPT, custom MCP servers are added as Apps through Developer mode. Availability depends on your plan. Business, Enterprise, and Education workspaces may need an admin to enable it first. See OpenAI's article Connecting custom MCP servers in ChatGPT for additional details.

Enable Developer Mode

For Business, Enterprise, and Education accounts, a workspace admin can enable developer mode under Workspace settings → Permissions & roles → Developer mode / create custom MCP connectors. For Individual plans, go to Settings → Apps → Advanced settings and turn on Developer mode.

Create the Carbon Signal App
  1. Go to Settings → Apps and click Create. Admins can also create apps for the whole workspace under Workspace settings → Apps → Create.
  2. Enter the details: For Name use Carbon Signal, for Description use Building energy, emissions, and intervention data from Carbon Signal, for MCP Server URL use https://api.carbonsignal.com/mcp, and for Authentication use OAuth
  3. Confirm that you trust the app, then click Create
  4. Sign in with your Carbon Signal account credentials when prompted and approve access. ChatGPT will scan the server and list the available tools.
Using it in a Chat

Click + in the message box, choose More, and select Carbon Signal. You can also ask ChatGPT to "use Carbon Signal" in your prompt. For additional information, see Connecting custom MCP servers in ChatGPT.

note
With the exception of absolute emissions (metric tons), all values come from Carbon Signal in imperial units (feet, kBtu, etc.) by default. If you'd like to work with metric units, just ask the assistant to convert values at the beginning of the chat session.