When HellouOne opened its public MCP server, hosted assistants such as claude.ai and ChatGPT could already sign in with a click. Cursor was the exception: you created a personal token in the dashboard, copied it and pasted it into Cursor's configuration file. That step is gone. Since 9 October 2026, Cursor signs in to the HellouOne MCP server through its own OAuth flow, and the server publishes the discovery metadata that lets any AI agent client work out how to authenticate without being told.
If your team writes code in Cursor and handles customers in HellouOne, this is the shortest path yet between the two: one line of configuration, one approval page, and the AI agent in your editor can read your conversations, contacts and reports with the permissions you chose.
What changed for Cursor
You add the server to Cursor with only its address. In your MCP configuration that is an entry named hellouone whose single setting is the URL https://mcp.hellou.ai/mcp, with no headers and no token. The first time Cursor uses it, it opens the HellouOne consent page in your browser. An administrator signs in, picks the account, decides whether the AI agent may make changes, and approves. The browser hands control back to Cursor, which now holds its own access token.
Under the hood this is the standard OAuth 2.1 authorization code flow with PKCE. HellouOne accepts redirects to HTTPS addresses, to the computer itself (loopback) and to approved desktop app schemes such as cursor://, which is what lets the approval page return straight to the editor. Access tokens last one hour and refresh tokens rotate each time they are used, so Cursor stays connected without you ever handling a secret.
Discovery metadata for AI agent clients
The second change is less visible but matters more over time. An MCP client that has only a URL needs to find out, on its own, where to sign in and what it may ask for. HellouOne now answers every one of those questions in public, machine-readable documents:
A request without a token gets a 401 response whose WWW-Authenticate header points to the protected resource metadata at /.well-known/oauth-protected-resource.
That document names the resource (https://mcp.hellou.ai/mcp), the authorization server (one.hellou.ai) and the two scopes on offer, mcp:read and mcp:write.
The authorization server metadata at /.well-known/oauth-authorization-server lists the sign-in, token, registration and revocation endpoints, PKCE with S256 only, and the grant types supported.
Clients register themselves dynamically (RFC 7591), so there is no developer portal to visit and no client ID to request by email.
The result is that an AI agent client which follows the MCP authorization spec can go from a bare URL to a signed-in session with no custom code for HellouOne. Cursor now uses this path end to end, as claude.ai and ChatGPT already did, and any new client that follows the same standards gets the same treatment.
Personal tokens still work
Nothing breaks for existing setups. Claude Code and clients that cannot open a browser sign-in keep using personal tokens: an administrator creates one under Settings, Integrations, AI clients (MCP), names it after the client, picks an expiry, decides whether it may make changes, and pastes it once into the client's configuration. If you already connected Cursor with a token, it keeps working; switch to sign-in whenever you like by removing the header from the entry and approving the consent page.
How this works with HellouOne
The MCP server is a door into the same HellouOne account your team already uses: the shared WhatsApp inbox, the AI agents that answer customers, contacts and labels, automation rules, reports and settings. A connection made through Cursor sees exactly what the approving administrator allowed. Leave changes off and the AI agent in your editor can search, summarise and report but cannot send a message or edit a setting. Turn changes on and every tool that writes data is marked as such, so Cursor asks before it runs one, and each change lands in the account's audit log.
In practice that means a developer can ask Cursor which conversations mention a bug they are fixing, pull the exact wording a customer used, or check how many chats a release generated, without leaving the editor or exporting anything. Every connected app is listed under Settings, Integrations, AI clients (MCP), where an administrator can disconnect it at any time. The HellouOne MCP integration page explains what the server can do, and the MCP documentation has the ready-made setup prompt, the JSON for Cursor and the full OAuth details.
