Why use an AI assistant with a spaced-repetition app?
Assistants are good at drafting flashcards: paste notes, ask for small question-and-answer cards, get a set back in seconds. What a chat cannot do is bring those cards back at the right time. A set of cards in a conversation has no review schedule, no record of what you got wrong, and no way to pick up next week where you left off.
Cirello closes that gap. It runs a hosted MCP server, so a connected assistant can create the cards directly in your library, where FSRS-6 schedules every review from then on. The assistant drafts; Cirello remembers and schedules. You approve what the assistant is allowed to do, and you still do your reviews in Cirello.
The server address is the same for every client:
https://api.cirello.app/mcp
It is a remote server using the Streamable HTTP transport, with OAuth 2.1 sign-in in your browser (authorization code with PKCE, dynamic client registration and standard discovery metadata). Clients that only run local servers, or that cannot do OAuth sign-in, cannot connect.
Which AI assistants work with Cirello?
Last checked 2026-10-30 against each vendor's public documentation. Menus and plan rules change often, so treat the "caveat" column as the thing to confirm in your own account.
| Assistant | Works? | Caveat |
|---|---|---|
| Claude (web, desktop, Claude Code) | Yes | Custom connectors; team plans need an owner to add them |
| ChatGPT | Yes | Turn on developer mode; works on the free plan |
| Gemini CLI | Yes | Needs a local browser for sign-in |
| Gemini app | Possibly | Reported by third parties, not confirmed in Google's own documentation we could reach |
| Cursor | Yes | None known |
| VS Code with GitHub Copilot | Yes, with caveats | Some versions have reported trouble with dynamic client registration; your organization may restrict servers |
| Codex CLI | Yes | None known |
| Perplexity | Yes, with caveats | Custom connectors reported on paid plans only |
| Microsoft Copilot | Only through Copilot Studio | The consumer Copilot app does not let you add your own server |
| LM Studio, Windsurf | Not confirmed | We could not confirm OAuth sign-in for remote servers |
Pages for each of the main clients have step-by-step setup. The rest are covered below.
Cursor
Cursor's documentation says remote servers use Streamable HTTP or SSE with OAuth, via the authorization code flow with PKCE, and that dynamic client registration is supported. Add Cirello to ~/.cursor/mcp.json (all projects) or .cursor/mcp.json (one project):
{
"mcpServers": {
"cirello": {
"url": "https://api.cirello.app/mcp"
}
}
}
Restart Cursor if the entry does not show up, then follow the sign-in prompt for Cirello. See Cursor's MCP documentation.
VS Code with GitHub Copilot
VS Code can add a remote HTTP MCP server from the MCP: Add Server command, or from an mcp.json file:
{
"servers": {
"cirello": {
"type": "http",
"url": "https://api.cirello.app/mcp"
}
}
}
Follow the sign-in prompt when it appears. The caveats: VS Code's documentation says only that you follow the publisher's sign-in instructions, and users have reported dynamic-client-registration problems in some versions, so update VS Code first if the sign-in fails. Organizations can also restrict which servers are allowed. See VS Code's MCP documentation.
Codex CLI
Codex reads MCP servers from ~/.codex/config.toml. Per OpenAI's Codex documentation, a Streamable HTTP server needs only a url, and OAuth is the default:
[mcp_servers.cirello]
url = "https://api.cirello.app/mcp"
Then run codex mcp login cirello and sign in in the browser. See OpenAI's Codex MCP documentation.
Perplexity
Third-party guides report that Perplexity's custom remote connectors are available on paid plans (Pro, Max and Enterprise) and that it registers itself with OAuth dynamic client registration, which Cirello supports. The setup is under Settings > Connectors, adding a custom remote connector with the URL above. We could not reach Perplexity's own help page, so confirm the plan requirement in your account.
Microsoft Copilot
Microsoft's consumer Copilot app does not let you add your own MCP server. Copilot Studio, Microsoft's agent builder for organizations, can connect to a remote MCP server over Streamable HTTP with OAuth, including dynamic client registration. That is a path for teams building their own agents, not for personal use, and we have not tested it with Cirello.
What does not work
Clients that only support local (stdio) servers cannot reach a hosted one. LM Studio documents remote servers with a static authorization header and does not document OAuth sign-in, and we could not confirm OAuth in Windsurf's current documentation, so we do not list them as supported. If that changes, this page will.
What an assistant can do in Cirello
Once connected, you can ask for things like "turn these notes into cards in a deck called Biology", "what is due today", "find my duplicate cards" or "split this card into three". Cards are created up to 50 per request, only with the permissions you approved, and deleting is off unless you allow it. Grades are recorded only for cards you actually tried to answer, and you can undo one within a minute. The full list is on the Cirello MCP server page; good prompts start from how to write good flashcards.
Limits to know about
Cirello is a web app today, with iOS and Android apps planned. There are no cloze deletion cards yet. An assistant can write cards, but what is worth remembering is still your decision, so skim what it creates. The MCP server is part of the free beta.