MCP Connector Plugin

The bundled MCP plugin connects Model Context Protocol servers and makes their tools available to Chetty. It supports local stdio processes and remote streamable http connections; for adding a server and using its tools, see MCP.

Local computer targets

HTTP and API-only MCP operations remain usable in local conversations. For a selected paired computer, stdio servers run on that computer with its installed commands and working directory, so the server's command must be installed there and its credentials configured there.

Centrally stored command environment variables are refused for such a server: configure its credentials on the computer itself. A disconnected operation fails with LOCAL_EXECUTION_LOST and is never replayed or run on the Chetty host.

Manage MCP servers

Open MCP in the sidebar, or run /mcp in the CLI, to inspect servers and their state.

The MCP page

Each server shows its transport, ownership, tool count and state. From the page you add, enable, disable, reconnect and delete servers, one at a time or several at once, and Reconnect all retries the disconnected and failed ones. Steps are in Manage MCP servers.

The CLI picker

/mcp lists your personal servers and the instance servers you may manage, each with ownership, connection state, sign-in state and discovered tools. Ownership and name together identify a server, so two scopes can hold servers with the same name.

Press Enter for details, r to reconnect the selected server, R to retry enabled servers that are disconnected or failed, and Ctrl+L to refresh. A reconnect result reports the state the server returned, not just whether the request succeeded, and a connected server with no tools is valid.

For an HTTP server that needs authorization, select Sign in in the detail picker. The CLI opens the address in your browser and keeps it in a notice, so you can copy it by hand, including over SSH.

Finish with the same Chetty account, then select Refresh status, which only reads the current state; no background process waits for the browser. Escape leaves a pending sign-in until it expires after ten minutes, and starting again replaces it. Sign out clears the server's credentials and cancels any pending sign-in.

Reconnect all reports how many servers connected, were verified in their managed Project, need sign-in or failed, with a message for each failure. It is available only while the plugin is enabled.

The telemetry rail

The conversation's telemetry rail carries an MCP section with the number of connected servers out of all configured ones, listing the connected servers and any that need sign-in. Selecting a row opens the MCP page.

What saving checks

An enabled server is verified and its tools discovered when saved. An HTTP server that needs OAuth stays stored with its sign-in action, and a failed setup shows Sign-in error with a message naming what failed; both survive a Chetty restart.

Other verification failures are reported without keeping the change, and the provider's own answer is never displayed. Removing a server makes its tools unavailable immediately. Saving the plugin's settings, or enabling or disabling the plugin, asks Chetty to restart.

Server settings

The Server settings group starts open and remembers whether it is folded, separately for each server. Ownership and transport are dropdowns, arguments and environment values are multiline fields, and changes still need Save. Connection status and sign-in actions stay visible while the group is folded.

OAuth setup

OAuth requires a configured public web URL for the instance.

Keep the public address stable for as long as the connection is used, including later token refreshes. If you change the public origin and restart, the client identity and the callback address change, so sign out and sign in again.

Disabling the MCP plugin removes the public client document, and the authorization server can then no longer identify this client. How Chetty registers as a client is described in MCP OAuth.

To switch from a stdio OAuth proxy to a direct HTTP connection, add the HTTP address and sign in to it. Credentials are tied to the server name and address, so the new entry needs its own sign-in; verify the direct connection and its tools before you retire the proxy.

OAuth browser callback

After you approve access, the provider returns you to the MCP callback page, which confirms the sign-in and sends you on to MCP. The sign-in code never stays in the address bar and the callback entry is replaced in your history, so Back cannot submit it again.

A request that expired, was denied or was not recognized shows its own message with Back to MCP, and a failure is never replayed. If you arrive signed out, Chetty asks you to sign in first and then completes the pending sign-in while its ten minutes have not passed. The full flow is in Sign in to an MCP server.

Connection behavior

A server can publish resources without tools and still connect. Zero tools is a valid result, and tools are discovered only when the server advertises them.

When each server connects

Instance servers connect when the plugin loads, and personal remote servers connect when one of their tools is first called. Until then a personal server's tools come from its last successful discovery, so reconnect it when it has none.

Personal tools are registered only for the account that owns them, while instance tools are available to every conversation. Account tool permissions can still restrict individual tools. The retry rules behind these states are in MCP connections.

stdio servers

A stdio server runs a command as a local process, and only instance administrators may create or start one, even when it is labelled personal. Its arguments are passed to that command and its environment values are available to it, so configure only commands you trust. Remote HTTP servers never run a local command.

Project-bound servers

A stdio server created while a managed Project is selected is bound to that Project and runs there; the binding cannot change later. Saving the binding checks your current access to the Project even when the server is disabled.

After a successful reconnect, a server bound to a managed Project is reported as verified in its project rather than connected, and Reconnect all counts these separately from live connections and failures.

MCP tools

AddMcpServer requires an ownership scope, either personal or instance. Adding a server that needs OAuth reports that the server was saved and points you to the MCP page for an explicit sign-in.

A failed setup returns an error that carries the saved server and a safe message, and never claims a connection. Neither that tool nor ReconnectMcpServer starts a sign-in on its own.

Server-provided tool definitions can be viewed on the MCP page but not edited; change them on the server itself. The resource tools are read-only.

Each binary read writes a new file and leaves earlier files in place, so a path from an earlier read still holds its bytes. The result returns the path once the file is complete, and an incomplete file is removed when saving fails.

An error a server returns as content stays readable, and connection and timeout failures are reported as tool errors.

Ownership and credentials

Personal servers belong to the linked account that created them, and only that account can manage and use them; Instance servers are shared and managed by administrators. Creating a personal server requires a linked account, and creating, updating, removing or reconnecting an instance server requires administrator access. The plugin is not user-grantable and asks for no separate consent when enabled.

The editor shows the names of configured environment variables, never their values. Enter a new value as KEY=value; leaving the field empty keeps the existing values. ListMcpServers never returns credentials, commands or environment values.

A remote HTTP server can move between the instance scope and your personal scope; a stdio server cannot change scope, so create it again on the other side. Credentials are cleared when the server is deleted, when its address changes, when its ownership transfers, or when its personal owner account is removed.

Removing an account also removes its personal servers and their saved tool discoveries. Stored SSE servers are unsupported and never connect; replace them with streamable HTTP servers.

Settings and limits

In Settings → Plugins, open the MCP plugin settings to set both timeouts. They apply to all servers.

Timeouts

A value outside the range is set to the nearest allowed value.

Names and addresses

A server name must be 1 to 40 characters, start with a letter or number, and contain only letters, numbers, underscores and dashes; names are unique within an ownership scope. A description holds up to 2,048 characters.

HTTP addresses must use HTTP or HTTPS and cannot include a username, a password or a query parameter that looks like a secret, such as a token or an API key.

Returned content

Tool names are normalized to lowercase words separated by underscores, with each server and tool name limited to 40 characters. Images returned by a tool are resized so that neither edge exceeds 2,000 pixels, and other non-text results are replaced with a short placeholder. A binary resource in a managed Project is limited to 16 MiB.