Connect an assistant

Arx has a local MCP server built in. Turn it on, connect Claude Code, Codex or Cursor with one command, then grant what it may see.

Your assistant can use your browser, but only the parts you hand it. Arx runs a local MCP server on your Mac. An assistant connects to it, you choose the spaces it can see and what it may do there, and you keep your passwords to yourself.

The server starts turned off, and a new client can do nothing until you grant it access.

Recording planned

Run 'arx setup claude' in Terminal, click Connect in Arx, grant the Work space with Read and Page content, then ask Claude Code to list the open tabs.

1. Turn on the server

Open Settings → Advanced → Local assistants (MCP) and turn on Enable local MCP server. The pane then shows Running locally, the connected sessions and recent activity.

2. Put `arx` on your PATH

The arx command ships inside Arx. Run it once from the app bundle to link it into ~/.local/bin (change the path if Arx isn't in Applications):

/Applications/Arx.app/Contents/Helpers/ArxMCP setup command

If ~/.local/bin isn't on your PATH, the command tells you to add it. The link keeps working when Arx moves or updates.

3. Connect your agent

arx setup claude   # Claude Code
arx setup codex    # Codex
arx setup cursor   # Cursor

Arx then asks Connect Claude Code to Arx? Click Connect. The request came from the arx command on this Mac, and an agent can't approve its own setup: if nobody approves, the command exits with code 3.

What arx setup writes:

Agent	Configuration
Claude Code	Runs `claude mcp add --scope user arx -- ~/.local/bin/arx mcp --client claude`
Codex	Adds a `[mcp_servers.arx]` table to `~/.codex/config.toml` and leaves the rest of the file alone
Cursor	Adds `mcpServers.arx` to `~/.cursor/mcp.json`

The agent's configuration only names the client (arx mcp --client <agent>). The credential lives in a private file under ~/Library/Application Support/Arx/AgentClients/, readable only by you.

4. Grant access, then restart the agent

The new client starts with No context granted. In the same Settings pane, pick what it may see and do: see Grants and approvals. Restart the agent afterwards so it picks up the server.

Changing a grant later updates a connected assistant without disconnecting it: its tool list changes and the server sends notifications/tools/list_changed. Revoking a client disconnects it.

Other MCP clients

Any MCP client that can launch a local command can connect. In Local assistants (MCP), click Add client, name it and copy the Client configuration. It contains a credential that is shown only once, so store it privately and restart the client after you change its permissions.

Check and undo

arx status          # whether Arx and its MCP server are running, and who's connected
arx status --json   # the same, for scripts
arx remove claude   # take an agent out again
arx remove command  # remove the arx link from ~/.local/bin

arx guide prints a short explanation written for agents. Exit codes: 0 done, 1 failed, 2 usage, 3 needs you.