Connect an MCP client
Give an external assistant authorized access to Cantinarr's tools through its own browser sign-in.
Cantinarr exposes a Model Context Protocol server at /mcp using Streamable HTTP. A compatible client can discover tools, sign in through Cantinarr, and act with that user’s permissions.
Use the server endpoint
Section titled “Use the server endpoint”Enter your reachable Cantinarr origin followed by /mcp, for example:
https://media.example.com/mcpUse your client’s supported remote HTTP MCP connection method. Some clients use a configuration shaped like this:
{ "mcpServers": { "cantinarr": { "url": "https://media.example.com/mcp" } }}Client configuration formats differ. This example identifies the endpoint; it is not a universal command for every MCP application.
Complete browser authorization
Section titled “Complete browser authorization”The client discovers Cantinarr’s OAuth metadata and opens its sign-in page. Sign in with an allowed method, review the client, and choose Authorize.
Password, passkey, configured OIDC, and enabled Plex sign-in paths follow the account’s policy. Required OIDC still applies to regular users. On plain HTTP, browser passkeys may be unavailable, so a permitted password is needed for that path.
Connect links are not bearer tokens to paste into a client configuration. The external client receives its own authorization tied to a Cantinarr device record.
Behind a reverse proxy
Section titled “Behind a reverse proxy”Set a stable canonical HTTPS origin:
environment: CANTINARR_OAUTH_ISSUER: https://media.example.comThis is the external address, not the arr callback address. Changing the issuer can require existing clients to reconnect because their tokens are bound to the prior audience.
For browser-hosted clients, configure CANTINARR_MCP_ALLOWED_ORIGINS only for additional actual browser origins that should call /mcp. If neither it nor the issuer is configured, requests carrying an Origin header are rejected. Native and server-side clients without that header do not need an extra origin entry.
Permissions and tools
Section titled “Permissions and tools”The current account’s role, grants, kids policy, and request allowances apply. Administrative tools remain administrative. Settings > AI Tools can disable shared tools for chat and MCP.
The server also provides an operating-guide resource and prompt templates. See the complete tool reference for exact arguments and limits described by the maintained server docs.
External profile changes become proposals for review inside Cantinarr. The in-app-only apply tool is not exposed to external clients.
Revoke a client
Section titled “Revoke a client”Revoke its device in Connected Devices. This also invalidates its associated MCP access. Registered clients and token records survive normal server restarts, while revoked devices remain revoked.
This is separate from an AI provider link
Section titled “This is separate from an AI provider link”MCP authorization lets another client access Cantinarr. Linking ChatGPT or xAI under AI Access lets Cantinarr call that provider. Completing one does not configure the other.
If tools do not load, check the exact endpoint, proxy routing, canonical issuer, browser-origin policy, current device authorization, and tool toggles. Do not paste tokens into a public support report.