Why is mcpdoc (LangChain) not working in ChatGPT (Codex)?

It failed in our test on Oct 22, 2026. Errors we observed: no successful call to this server's tools; answer missing ['5173']; no tool result containing ['5173']; no successful call to this server's tools; answer missing ['5173']; no tool result containing ['5173']

mcpdoc (LangChain) not working in ChatGPT (Codex)? Fixes

Failed It failed in our test on Oct 22, 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: Oct 22, 2026 · From our harness, not the maker’s claims · How we test

1. Use the install config we tested in ChatGPT (Codex)

[mcp_servers.mcpdoc]
command = "uvx"
args = ["--from", "mcpdoc", "mcpdoc", "--urls", "Vite:https://vite.dev/llms.txt", "--transport", "stdio"]

Replace any <YOUR_…> placeholder and local test paths with your own. Every client’s tested snippet is on the mcpdoc (LangChain) 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 server

Errors we observed

agent task: docs fact: no successful call to this server's tools; answer missing ['5173']; no tool result containing ['5173']
agent task: docs fact (tool error during the run): no successful call to this server's tools; answer missing ['5173']; no tool result containing ['5173']

Quoted from our run log. Secrets redacted. We list only what we saw.

More help

mcpdoc (LangChain): all results and setup · Full ChatGPT (Codex) run · General ChatGPT (Codex) MCP troubleshooting