The Kotzilla MCP server gives your AI assistant data from real user sessions: which screens are slow, which components block the main thread on them, and how long each one takes. Then it helps you fix them.
Set up Kotzilla MCP server using https://kotzilla.io/llms.txt“Crashlytics told us the app froze, but not why. Kotzilla showed us the screens and the components that were blocking the main thread, and we fixed them release after release, measuring the difference each time. We then automated it: Claude Code is connected to the Kotzilla MCP Server, reviews the ANRs of each new release every week and proposes the fixes.”
In Claude Code, run this one command from your terminal. There is no file to edit.
claude mcp add kotzilla --transport http https://mcp.kotzilla.io/mcp
Using Cursor, Windsurf or Android Studio? The setup for each one is just below.
{
"mcpServers": {
"kotzilla": {
"command": "npx",
"args": [
"-y",
"mcp-remote",
"https://mcp.kotzilla.io/mcp"
]
}
}
}
The first call asks you to sign in with a Kotzilla account. The free tier is at console.kotzilla.io. Creating one takes a minute and needs no card.
Your assistant adds the version catalog entry, the Gradle plugin, the kotzilla.json file, and the SDK initialisation. Run the app once to record your first sessions.
Paste this prompt into Claude Code, Cursor, Windsurf, Android Studio, or any AI assistant that supports MCP.
Your assistant reads the setup instructions, adds the server, and then asks you to sign in with your Kotzilla account. No account yet? Create a free one at console.kotzilla.io. No card is needed.
Paste this prompt into your assistant.
Your assistant detects your project structure, registers the app and applies the SDK changes: the Gradle plugin, the configuration files and the initialisation code.
Assistants without an add command read the server from a configuration file. Add this block to it:
{
"mcpServers": {
"kotzilla": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://mcp.kotzilla.io/mcp"]
}
}
}.cursor/mcp.json~/.codeium/windsurf/mcp_config.jsonhttps://mcp.kotzilla.io/mcp. If it cannot connect over HTTP directly, use the block above.Claude Code reviews the ANRs of the new release through the Kotzilla MCP server and proposes the fixes.
Try it on your app:
An answer names the component, the screen it sits on, how long it took to build, and the thread it ran on. These come from sessions your own app recorded, so the SDK goes in first and the app has to run at least once.
These are our own thresholds and they are stricter than Android's. Android shows the app is not responding message when your app does not handle an input event within five seconds.
These are our own thresholds, and they are stricter than Android's. Android's own limit before it shows the app is not responding message is five seconds.
Kotzilla is an observability platform for Kotlin developers who use Koin. It tracks crash-free rate, ANR-free rate, cold and warm start times, and slow screens, and links each problem to the components and dependencies that cause it. It is built by the team that created Koin, and it works for Android and Kotlin Multiplatform apps, in development and in production.
The MCP Server connects your AI coding assistant to the Kotzilla Platform. It gives your assistant the structure and runtime data that Kotzilla records from real user sessions, plus a set of tested Kotlin fix patterns. With it, your assistant can register your app, look at production issues, and apply fixes in your code.
Any assistant that supports MCP, including Claude Code, Cursor, Windsurf, and Android Studio through its AI plugins (JetBrains AI Assistant and Junie). The setup prompt above works in all of them.
The MCP Server only passes queries between your AI assistant and the Kotzilla Platform. On the Kotzilla side, it reads the same technical session data that the Kotzilla SDK already collects, and that data contains nothing sensitive. No business logic or user data is shared.
Slow cold and warm starts, slow screens and slow screen transitions, ANRs, and slow work on the main thread and on background threads. It also reports crashes in Android apps, Kotlin Multiplatform apps and SDK libraries, together with the other issues found in the same sessions.
Yes. The developer plan is free, with no time limit and a limited number of events. You do not need to enter payment details.
Yes. Since SDK 2.3.0, the Kotzilla SDK runs on apps that use Hilt, Metro, Dagger or manual dependency injection. You get sessions, cold and warm start times, render times for each screen, ANRs, crashes and lifecycle events. The Koin dependency graph, and the component-level issues that come from it, need Koin.
Yes. It reports component issues, dependencies and crashes on both Android and iOS devices.
The Kotzilla SDK 2.0.x needs Koin 4.0.4 or higher. If you use SDK 1.4.x, Koin 3.5 and higher is still supported.
More answers in the Kotzilla documentation FAQ.