Skip to content

Runtime reference

Krometrail ships one Rust binary and one composition root. The runtime assembles browser transport, controlled-browser capture, recording storage, and retention before dispatching a command.

Commands

CommandCurrent behavior
krometrail --versionPrints the Cargo package version and exits successfully.
krometrail --helpPrints the available command surface and exits successfully.
krometrail doctorReports discovered Chrome/Chromium installations or a structured browser_not_found failure. It does not launch a browser.
krometrail mcpServes the browser-control tool registry over MCP stdio until transport EOF or process shutdown.

krometrail mcp writes only MCP JSON-RPC traffic to standard output. It owns at most one controlled browser session and uses ownership-aware shutdown: managed browsers close, while explicitly attached browsers detach. The default server publishes 37 tools: four lifecycle tools, 24 registry-derived browser-control tools including ordered batching, temporal_debug_bundle, seven temporal evidence/retention tools, and query_browser_events.

Temporal evidence is persisted by the durable recording store. Temporal tool responses can include bounded inline images and canonical resource links. The server exposes two dynamic resource templates for retained artifacts and source frames; concrete resources are read with resources/read using krometrail://evidence/{session}/{target}/artifacts/{id} or krometrail://evidence/{session}/{target}/frames/{id}. Page-state and framework-state remain unavailable extension capabilities, not current tools.

The root CLI is defined in src/cli.rs, and the full composition root is in src/app.rs. See MCP configuration for a client entry and SPEC.md for the broader intended external contracts.