Command reference
Krometrail provides four command-line entry points:
| Command | What it does |
|---|---|
krometrail --version | Prints the installed version. |
krometrail --help | Lists the available command surface. |
krometrail doctor | Finds local Chrome and Chromium installations without launching a browser. Returns a structured browser_not_found error when none is available. |
krometrail mcp | Serves Krometrail to an MCP client over standard input and output until the client disconnects or the process stops. |
doctor
Use doctor as the terminal health check for browser discovery:
krometrail doctorIt does not launch a browser, change a profile, or start recording. Doctor never initializes, reclaims, validates, or reads recording storage or recording configuration: an unusable data directory or an invalid recording setting cannot block discovery. Diagnostic logging stays on and stays best effort: discovery is appended to the data directory's diagnostics log when that location is writable, and an unwritable location only produces a warning on standard error.
mcp
An MCP client starts this command for you:
krometrail mcpIt is not an interactive terminal command. Standard output is reserved for MCP protocol messages. Krometrail writes bounded private diagnostics under its platform data directory and returns the log path plus a correlation identifier on failed or degraded MCP calls. Standard error is reserved for startup failures that occur before file diagnostics are available.
The same stdio command supports MCP 2026-07-28 discovery and initialization at 2025-11-25 or 2025-06-18. Modern tool discovery is paginated; follow every nextCursor. Legacy versions receive the complete catalogue in one response.
The MCP server gives an agent:
- managed browser launch or explicit local attachment;
- page navigation, inspection, interaction, and current screenshots;
- continuous recording during the controlled session;
- temporal bundles, storyboards, difference maps, filmstrips, motion history, and source frames;
- nearby console, exception, navigation, and request metadata;
- local retention and pinning of important intervals.
The server owns at most one active browser session. A Krometrail-managed browser closes when the session or MCP transport ends; an externally owned browser is detached rather than closed.
See Manual MCP configuration to connect a standalone binary.