How to save words to Koboshi from Claude Code and Codex

How to September 28, 2026 1 min read Waqas Shota Ali (アリワカース章太)

Ask Claude Code or Codex to save any word to Koboshi, and the word lands in your Koboshi vocabulary.

Each app takes two commands in a terminal and one sign-in.

Claude Code

In a terminal, run:

claude mcp add --scope user --transport http koboshi https://koboshi.app/mcp

Run this, then sign in on the Koboshi page that opens and press Approve:
```
claude mcp login koboshi
```

Check: run the line below. The koboshi line reads ✔ Connected.

claude mcp list

In a terminal, run:

codex mcp add koboshi --url https://koboshi.app/mcp

Run this, then sign in on the Koboshi page that opens and press Approve:
```
codex mcp login koboshi
```

Check: run the line below. koboshi is on the list.

codex mcp list

One setup covers the Codex CLI, the IDE extension and the ChatGPT desktop app.

Claude Code finds Koboshi in one folder only: run step 1 again. The --scope user part makes it work in every folder.
Claude Code shows “! Needs authentication”, or claude mcp login is not found: start Claude Code, type the line below, pick koboshi and sign in.
```
/mcp
```
Codex looks different from this page: these steps follow OpenAI’s documentation; tell us at support@koboshi.app.

Using ChatGPT or Claude? Connect them here. Steps checked on 2026-09-29.