Jupyter MCP not working in ChatGPT (Codex)? Fixes
Failed It failed in our test on Oct 15, 2026. Below is the exact setup we used in ChatGPT (Codex) (codex-cli 0.162.0-alpha.17.2), every error we saw, and what to check, all from our own run log.
Date tested: · From our harness, not the maker’s claims · How we test
1. Use the install config we tested in ChatGPT (Codex)
[mcp_servers.jupyter]
command = "uvx"
args = ["jupyter-mcp-server"]
env = {JUPYTER_URL="http://127.0.0.1:8888",JUPYTER_TOKEN="•••",DOCUMENT_URL="http://127.0.0.1:8888",DOCUMENT_TOKEN="•••",RUNTIME_URL="http://127.0.0.1:8888",RUNTIME_TOKEN="•••",DOCUMENT_ID="notebook.ipynb",ALLOW_IMG_OUTPUT="false"}Replace any <YOUR_…> placeholder and local test paths with your own. Every client’s tested snippet is on the Jupyter MCP page.
2. Check that ChatGPT (Codex) connects to it
In our run the connect check was not run. Our check output:
no tool call reached the serverErrors we observed
- agent task: run cell: no successful call to this server's tools; answer missing ['42']; no tool result containing ['42']
Quoted from our run log. Secrets redacted. We list only what we saw.
More help
Jupyter MCP: all results and setup · Full ChatGPT (Codex) run · General ChatGPT (Codex) MCP troubleshooting
