mxr

AI Model Router command-line client.

Install

npm install --global mxr
mxr login

Requires Node.js 18 or newer.

Commands

Run mxr --help for the current command list.

Long agent sessions compact automatically before the active model reaches its context limit. Use mxr, then /compact, to compact immediately; /status shows the current token estimate. Older tool output is pruned automatically, while goals, decisions, completed work, and relevant files are retained in a continuation summary.

Use /reasoning to choose auto, none, low, medium, or high. Auto mode selects a level per request and shows the effective choice in the header, for example think:auto→medium. Grok 4.5 safely falls back from none to low. The same default can be set outside the TUI with mxr config --reasoning auto.

The TUI keeps messages left-aligned, persists tool activity as compact cards, and renders file edits as a unified diff in narrow terminals or a side-by-side diff when the terminal is wider than 120 columns. Grok requests reuse a stable prompt cache key and report live streaming progress. Grok 4.3, Grok 4.5, and Grok Build 0.1 are supported by the xAI Responses adapter.

MCP and Codex-format plugins

MXR is an autonomous MCP client; Codex does not need to be installed. Every model available through MXR receives the same connected MCP tools.

Add a Streamable HTTP server:

mxr mcp add docs --url https://example.com/mcp

Add a local STDIO server (the JSON form keeps command arguments portable):

mxr mcp add context7 --command npx --args '["-y","@upstash/context7-mcp"]'

Browser automation on Windows using the built-in Edge installation:

mxr mcp add playwright --command npx --args '["-y","@playwright/mcp@latest","--browser=msedge"]'

Playwright accessibility snapshots linked from tool output are expanded back into the model context. Screenshot image-content is forwarded through MXR's multimodal message path, so vision-capable models can inspect the actual frame.

Configurations are stored in ~/.mxr/mcp.json. Inside the TUI, /mcp shows connection state and /mcp reload reconnects all servers. You can also ask the agent in plain language to install an MCP; it uses the built-in install_mcp tool, asks for confirmation, saves the config, and connects it immediately.

MXR also accepts plugin packages that use the Codex layout .codex-plugin/plugin.json plus a manifest mcpServers entry:

mxr plugin install ./my-plugin
mxr plugin install https://github.com/example/my-plugin.git

Plugins are copied into ~/.mxr/plugins, so their original source and a Codex installation are not needed afterward. MCP tools are namespaced as mcp__<plugin>__<server>__<tool> to prevent collisions between plugins.

Check for a new release or install it from npm:

mxr update --check
mxr update

mxr checks for releases at most once every 24 hours and only shows a notification by default. Optional automatic updates can be enabled with:

mxr config --auto-update on
mxr config --auto-update off