FSB: MCP server, setup and security

What FSB does

According to its repository: “Chrome extension plus MCP server that lets any MCP client drive your own signed in Chrome by reading the live DOM instead of screenshots, with no API key. 69 tools, session replay, and an encrypted credential vault.”

The Model Context Protocol (MCP) is a standard plug between an AI agent and an outside service: once the server is connected, its tools show up in the agent, which decides when to call them. FSB is listed under Browser automation, a category of 109 servers in the directory, where it ranks #42 by stars.

Topics declared by the repository: browser-agent, chrome-extension, manifest-v3, full-self-browsing, agents, automation.

Installing and connecting FSB

No package or remote server is declared in the official MCP registry: you install it from source, following the repository README.

It works with any MCP-compatible client (Claude Desktop, Claude Code, Cursor, VS Code, Codex and most recent agents). You add one entry to the client's MCP configuration: server name, start command or URL, environment variables. Project language: TypeScript. Listed systems: macOS, Windows, Linux.

Security: what to check

Connecting an MCP server means installing software that talks straight to your agent: it runs with your rights and the model trusts its tool descriptions. The risk therefore depends on what it can touch and how far its code can be trusted.

Points found for FSB:

• System access: the Browser automation category gives the agent control over files, a terminal, code or a browser. A booby-trapped instruction in content the agent reads (prompt injection) can then turn into an action.

Good practice: grant only the rights needed (least privilege), require human approval for irreversible actions, and run the AI agent security check.

Project activity and maintenance

Created on July 29, 2025, the fullselfbrowsing/FSB repository has 203 stars and 17 forks, with 2 open issues. It has more stars than 78% of the servers in the directory. It received changes this month.

Stars measure attention, not quality: a recent, heavily promoted project can collect them fast, while a useful but niche server will have few.