Krometrail, developed by Nklisch, is a specialized MCP server tool for coding agents. Built with Rust and distributed as a native binary, it operates as a browser memory tool to record and preserve transient visual states in Chrome or Chromium sessions. It provides agents with deep insight into browser behavior beyond static screenshots, serving as a local server that connects to controlled browser environments. Krometrail is categorized as an mcps tool, enhancing agent capabilities for debugging and analysis of web interactions.

What does Krometrail connect to?

Krometrail connects directly to controlled Chrome or Chromium browser sessions. It functions as a local Model Context Protocol (MCP) server, specifically designed for coding agents to access browser memory. This connection allows it to capture and preserve transient visual states that might be missed by simple screenshots, providing a more detailed view of browser activity for analysis.

Core features and tools

Krometrail exposes several command-line tools: "krometrail --version" to check the installed version, "krometrail --help" to list available commands, and "krometrail doctor" to locate local Chrome or Chromium installations. The central command, "krometrail mcp", serves Krometrail to an MCP client over standard input and output, enabling features like browser launch, navigation, inspection, screenshots, continuous recording, temporal bundles, storyboards, difference maps, and motion history.

Who is it for?

Krometrail is primarily designed for coding agents and the developers who deploy and manage them. Its capabilities are tailored to enhance the debugging and analytical power of these agents within browser environments. It provides specialized tools for capturing and analyzing temporal visual data. Skip this if your workflow does not involve coding agents interacting with controlled browser sessions for visual state analysis.

How to get started

No credentials are required for Krometrail itself. Communication with MCP clients is handled via the "stdio" transport protocol.

Use cases

• Reproducing and inspecting transient visual problems such as flicker, layout jumps, or reversed animations in a controlled browser session.
• Providing coding agents with compact still-image evidence, including temporal bundles, storyboards, difference maps, filmstrips, and source frames, to debug visual issues.
• Enabling agents to look back at an interaction and inspect the temporal evidence around a described symptom without needing to predict the exact frame or script the capture.

Krometrail offers coding agents a powerful way to observe and debug browser interactions. Its ability to record transient visual states and provide rich temporal evidence is valuable for analyzing complex web behaviors. As a local MCP server, it ensures captured browser data remains on the user's machine, unless explicitly accessed by a connected agent. Try using "krometrail doctor" to confirm local Chrome or Chromium installations.