mcpbeat

Extensiondev MCP Server

io.github.extensiondev/mcp
local only

Extensiondev runs on your own machine — the client starts it, so there is no endpoint to ping. 1 007 installs a week from npm. Last commit 3 Aug 2026.

Build, run, inspect, and publish browser extensions from any MCP client. 28 tools, 11 browsers.

Installs per day peak 979 · avg 225 · -74% w/w
a month agotoday
1 007
Installs / week
npm · @extension.dev/mcp
1
Stars
0 open issues
3 Aug 2026
Last commit
0 releases in 90 days
Apache-2.0
License
TypeScript

Connect this server

This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.

run in your terminal
claude mcp add mcp -- npx -y @extension.dev/mcp
~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "mcp": {
      "args": [
        "-y",
        "@extension.dev/mcp"
      ],
      "command": "npx"
    }
  }
}
~/.codex/config.toml
[mcp_servers.mcp]
command = "npx"
args = ["-y", "@extension.dev/mcp"]
.cursor/mcp.json
{
  "mcpServers": {
    "mcp": {
      "args": [
        "-y",
        "@extension.dev/mcp"
      ],
      "command": "npx"
    }
  }
}
.vscode/mcp.json
{
  "mcpServers": {
    "mcp": {
      "args": [
        "-y",
        "@extension.dev/mcp"
      ],
      "command": "npx"
    }
  }
}

Extensiondev — questions

Answers built from our own checks of this server.

Why is there no uptime for Extensiondev?
Extensiondev runs on your own machine over stdio — there is no network address to reach, so uptime cannot be measured for it by anyone. What can be measured is adoption: the npm package @extension.dev/mcp was installed 1 007 times last week.
How do I connect Extensiondev?
Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It runs locally, so the command pulls @extension.dev/mcp straight from npm; nothing to host, nothing to sign up for.
How many people use Extensiondev?
The npm package @extension.dev/mcp was installed 1 007 times in the last week. Week over week that is -74%. We show installs rather than GitHub stars on purpose: a star is a bookmark, an install is someone actually running it.
Is Extensiondev open source?
Yes — it is published under the Apache-2.0 licence, written in TypeScript and 1 stars on GitHub. The source link is on this page, so you can read exactly what it does with your data before you connect it.