LLM Abacus

1. Open Claude (claude.ai or the desktop app).
2. Go to Settings → Connectors.
3. Click Add custom connector.
4. Paste the server address copied below into Remote MCP server URL and click Add.
5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
3. Open Settings → Connectors and click Create.
4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
3. Save the file. The server appears in the MCP list; authorize it there if asked.

If the service needs sign-in, an authorize button appears next to the server in the MCP list.