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Lymidocs

Assistants

ChatGPT and Codex

ChatGPT reaches Lymi through a custom connector, and the Codex CLI through its MCP config. Both sign in with OAuth; neither takes an API key.

MCP server URL
https://my.lymi.app/mcp

Once connected, ask it to add the cards from a lesson, list what is due, or find a card. What it can and cannot do is on Connect an assistant.

ChatGPT

Custom connectors need developer mode on the web, which Plus, Pro, Business, Enterprise and Education accounts have. OpenAI's help center limits write actions to Business, Enterprise and Education, so on Plus or Pro expect ChatGPT to read your decks but not change them. On a workspace plan an admin has to allow developer mode first.

By default ChatGPT asks before a write, such as adding cards or archiving a deck. You can let it remember your answer for a tool for the rest of the conversation.

  1. Turn on developer mode

    In ChatGPT on the web, open Settings → Apps → Advanced settings and switch Developer mode on.

  2. Create the connector

    Go to Settings → Connectors and choose Create. Give it a name, a short description, and the MCP server URL above. Leave the authentication fields alone: Lymi advertises OAuth through the protocol.

  3. Sign in

    ChatGPT sends you to Lymi. Sign in with the account your Lymi uses and approve the connection, unticking write if you want it read-only.

  4. Use it in a chat

    Enable the connector for the conversation from the composer, the same way as any other.

Codex CLI

Add the server, then sign in. Codex handles the OAuth round trip for you.

Terminal
codex mcp add lymi --url https://my.lymi.app/mcp
codex mcp login lymi

That writes an entry into ~/.codex/config.toml. You can also write it yourself:

~/.codex/config.toml
[mcp_servers.lymi]
url = "https://my.lymi.app/mcp"

Leave bearer_token_env_var out. That field is for servers that take a static token, and Lymi does not: it wants the OAuth flow, so that every grant is one you approved and can revoke.

When it does not connect

  • Sign-in is refused. Lymi is private. Only the accounts on its allowlist can sign in, whatever the OpenAI account is.
  • Registration fails. Lymi has no dynamic client registration, by design. ChatGPT and current Codex use a Client ID Metadata Document instead. If an older Codex tries to register, update it, or run codex mcp login lymi --oauth-client-registration cimd.
  • Writes are refused. The connection was granted read only. Reconnect and leave write ticked on the consent screen.