Rrweb Stack

What Cubenest/rrweb-stack MCP server does

The Cubenest/rrweb-stack MCP server connects an AI coding agent to browser activity captured by the Peek Chrome extension. It is part of the Peek product in the rrweb-stack repository; the same repository also contains Tracelane, a separate test-recording product that produces self-contained HTML reports.

Peek records the real browser session, including DOM changes, console messages, network activity, and screenshot fallbacks. Captured information is written to a local SQLite database and remains on the machine. The MCP surface lets an agent inspect those recorded sessions as structured data rather than relying only on a visual browser view.

The server also exposes live browser read and act capabilities. These capabilities require explicit consent and use a per-origin permission model, so an agent can be limited to observation or required to obtain confirmation before acting.

How it works

The Chrome MV3 extension records activity in the user’s authenticated browser. The shared rrweb-based capture layer supplies DOM recording, PII masking, large-DOM handling, console and network capture, compression helpers, and screenshot fallback behavior. Peek then makes the captured data available through its local MCP server.

Permissions are assigned per origin across five levels: Off, Read-only, Suggest-only, Act-with-confirm, and YOLO. Read-only is the default. Destructive actions remain subject to a blocklist that always prompts. This arrangement is intended to keep live browser control under the user’s control while still allowing agents to inspect pages and, when authorized, interact with them.

The server is designed for local MCP clients. The README specifically names Claude Code, Cursor, Cline, and Windsurf as supported agent surfaces.

Setup and configuration

Peek is distributed as alpha npm packages. The documented setup installs the Peek CLI globally and initializes it with npx peek init:

npm install -g @peekdev/cli
npx peek init

The initialization flow is the documented entry point for configuring Peek. The README does not provide a standalone command for launching @peekdev/mcp directly, so the CLI should be used rather than treating the package name as an executable command.

Node.js 22 or newer is required. Peek depends on better-sqlite3, which provides prebuilt binaries for Node 22 and later. Older Node versions may require a local native build; the README calls out Windows as a likely problem because a C/C++ toolchain is not included by default.

Tools and capabilities

The Cubenest/rrweb-stack MCP server supports these documented capabilities:

• Expose recorded browser sessions to MCP-compatible coding agents.
• Let agents query session data and export or inspect sessions through Peek’s session workflows.
• Provide live browser read operations subject to per-origin permissions.
• Provide live browser actions with consent controls and destructive-action prompts.
• Preserve captured data locally in SQLite under the user’s Peek data directory.
• Use PII masking during recording.

The repository describes the MCP package as exposing captured sessions plus consent-gated live read and act tools. It does not list individual MCP tool names in the supplied material.

Limitations and notes

The Cubenest/rrweb-stack MCP server is in alpha, as are the relevant Peek packages. It requires the Chrome extension and a local browser session; the supplied documentation does not describe support for other browsers. The extension is available on the Chrome Web Store, but the README does not state that installation alone starts or configures the MCP server.

There is no cloud service, telemetry, or remote storage described for Peek. That local-first design also means the agent depends on the local extension, CLI, SQLite data, and browser being available. Live control is not unrestricted: the default permission is Read-only, consent is required for higher-risk operations, and destructive actions are always prompted. No API key, hosted endpoint, or paid service is identified in the supplied material.