Connect ChatGPT / Codex

This page is for Codex CLI and the Codex tab in the ChatGPT desktop application. ChatGPT in the browser and regular chat in the desktop app use a different path. See Connect ChatGPT.

Install Chartbuddy Hub and launch it once before you add the server.

1. Open Settings

In the ChatGPT desktop app, click Settings in the bottom-left corner of the sidebar.

2. Plugins → MCPs

In the settings sidebar, open Plugins (under Integrations). Then open the MCPs tab.

3. Add server

On the MCPs tab, click + Add server.

4. Enter the Chartbuddy details

Choose Connect to a custom MCP (STDIO). Fields appear in this order — fill in every row:

Field	Value
Name	chartbuddy (or chartbuddy-mcp)
Type	STDIO
Command to launch	/Applications/Chartbuddy.app/Contents/MacOS/chartbuddy
Arguments	--mcp
Environment variables	leave empty
Working directory	leave the default

Windows command

C:\Users\YOUR_USER\AppData\Local\Programs\Chartbuddy\chartbuddy.exe — use this for Command to launch on Windows. A public Windows Chartbuddy Hub build is not shipping yet; use the macOS path until it does, then replace YOUR_USER (or use the path shown after install).

Click Save.

After saving

1. Keep Chartbuddy Hub running.
2. Start a new Codex session and enable the Chartbuddy MCP server for that session if tools do not appear.
3. If ChatGPT asks to approve network / loopback for chartbuddy, approve it — the adapter must reach Chartbuddy Hub on 127.0.0.1.
4. Optional check:

Windows

& "$env:LOCALAPPDATA\Programs\Chartbuddy\chartbuddy.exe" --mcp-status

macOS

/Applications/Chartbuddy.app/Contents/MacOS/chartbuddy --mcp-status

Exit 0 = Chartbuddy Hub is up.

Handoff

Optional context for a chat that will use the tools:

Chartbuddy MCP is configured (stdio → chartbuddy --mcp → Chartbuddy Hub).
Transport: newline JSON-RPC or Content-Length framed MCP — not HTTP docs.
Open charts: list_charts (chart-* refs). get_active_chart skips menus/popovers.
Missing tools usually mean the chartbuddy MCP server is off for the chat, or a new chat is needed.

Troubleshooting

Tool call blocked — “reasoning summaries” / organization verification

On the desktop Codex tab, Chartbuddy may be configured correctly and still fail when OpenAI’s automatic approval reviewer blocks the tool call — often with an error about “reasoning summaries” requiring organization verification. That comes from OpenAI’s approval / org settings, not from Chartbuddy or a bad MCP path.

Options:

1. Use Codex CLI instead of the desktop Codex tab (same MCP config, often fewer approval blockers), or
2. Verify your organization at platform.openai.com/settings/organization/general, or switch to another editor — we recommend Cursor, Claude Code, or OpenCode.