Tampermonkey MCP

MCP server to manage your Tampermonkey scripts

Quick Install

Automated & IDE Setup

Copy the AI prompt to install this server into Claude Code, Cursor, or another agent — or use 1-click editor setup below.

Add to Cursor Add to VS Code

Not yet automatically verified

We haven't yet run this listing's install command through our automated sandbox check. This isn't a red flag — we're steadily working through the catalog.

Manual Client & Custom JSON ConfigExpand JSON ▾

Client Config & Setup

Choose your client or environment

Target File:~/Library/Application Support/Claude/claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "tampermonkey-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "tampermonkey-mcp"
      ]
    }
  }
}

💡 Paste the JSON block into your client's configuration file under mcpServers, then restart the application.

Capabilities & Tool Schemas (6)Self-reported

Inspect callable tools, capabilities, and parameters exposed to AI agents by Tampermonkey MCP.

tampermonkey_get_connection_code

* **Purpose**: Initialize connection by getting the WebSocket connection code.

tampermonkey_list

* **Purpose**: List all available userscripts.

tampermonkey_get

* **Purpose**: Get content of a specific userscript.

tampermonkey_patch

* **Purpose**: Update userscript content.

tampermonkey_put

* **Purpose**: Create a new userscript with the given name and namespace.

tampermonkey_delete

* **Purpose**: Delete an existing userscript.

Documentation Overview

How to use

First install the following browser extensions:

Tampermonkey
Tampermonkey Editors for Firefox or Chrome

Then install tampermonkey-mcp globally:

Terminal

npm install -g tampermonkey-mcp@latest

Finally configure your AI assistant to use the tampermonkey tool:

JSON Config

{
  "mcpServers": {
    "tampermonkey": {
      "command": "npx",
      "args": [
        "-y",
        "tampermonkey-mcp@latest"
      ]
    }
  }
}

Your assistant will call tampermonkey_get_connection_code and return a connection code that you can enter in the Tampermonkey Editors extension.

Claude Code configuration example

Terminal

npm install -g claude

// either use your local checkout
npm run watch
claude mcp add --transport http --scope project tampermonkey http://localhost:4001/mcp

// or the npm package
npm install -g tampermonkey-mcp@latest
claude mcp add --transport stdio --scope project tampermonkey -- npx -y tampermonkey-mcp

// more browser control needed?
// Open chrome://inspect/#remote-debugging
// [x] Allow remote debugging for this browser instance
// or
chromium --user-data-dir=/tmp/chrome-devtools-mcp-test-profile --remote-debugging-port=9222

npm install -g chrome-devtools-mcp@latest
// install Tampermonkey and Tampermonkey Editors
claude mcp add --transport stdio --scope project chrome-devtools-mcp -- npx -y chrome-devtools-mcp@latest --slim --no-usage-statistics --auto-connect --browser-url http://127.0.0.1:9222

Build

Terminal

npm install
npm run all

Tampermonkey MCP Server Architecture

Overview

This project implements an MCP (Model Context Protocol) server that allows AI assistants to read and modify Tampermonkey userscripts via the Tampermonkey Editors browser extension.

Architecture Components

Code

┌─────────────────────────────────────────────────────────────────────────────┐
│                              AI Assistant                                   │
└─────────────────────────────────────────────────────────────────────────────┘
                                   │
                                   │ MCP Protocol (stdio transport)
                                   ▼
┌─────────────────────────────────────────────────────────────────────────────┐
│                         tampermonkey_mcp (MCP Server)                       │
│                                                                             │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  server.ts                    │  Main entry point                     │  │
│  │                               │  - HTTP or stdio transport            │  │
│  │                               │  - MCP middleware                     │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
│                                  │                                          │
│                                  ▼                                          │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  tampermonkey.ts              │  MCP Tool Definitions                 │  │
│  │                               │  - tampermonkey_get_connection_code   │  │
│  │                               │  - tampermonkey_list                  │  │
│  │                               │  - tampermonkey_get                   │  │
│  │                               │  - tampermonkey_patch                 │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
│                                  │                                          │
│                                  ▼                                          │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  tampermonkey-ws-client.ts    │  WebSocket Server                     │  │
│  │                               │  - Connection code generation         │  │
│  │                               │  - Authentication handshake           │  │
│  │                               │  - Message relay to extension         │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────────────────────┘
                                   │
                                   │ WebSocket (local, port derived from code)
                                   ▼
┌─────────────────────────────────────────────────────────────────────────────┐
│                   Tampermonkey Editors Extension                            │
│                                                                             │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  Service Worker               │  Receives connection code,            │  │
│  │                               │  establishes WebSocket connection     │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
│                                  │                                          │
│                                  │ Chrome Extension Messaging               │
│                                  ▼                                          │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  Content Script               │  Bridges extension ↔ Tampermonkey     │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
│                                  │                                          │
│                                  ▼                                          │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  Tampermonkey                 │  Userscript storage & execution       │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────────────────────┘

Connection Flow

MCP Server starts - Creates WebSocket server on a random available port
Connection code generated - Format: <base32(port - 1024)><auth_token><echo_token>
User calls tampermonkey_get_connection_code - Gets the connection code
User enters code in Tampermonkey Editors - Extension parses code to get port and auth
Extension connects to MCP server - WebSocket handshake with authentication
MCP tools become available - list, get, patch can now be called

Authentication Protocol

Code

Extension                              MCP Server
    │                                      │
    │───── auth (token) ──────────────────>│
    │                                      │
    │<──── auth (echo_token) ──────────────│
    │                                      │
    │───── auth (echo_token) ─────────────>│
    │                                      │
    │<──── authOK ─────────────────────────│
    │                                      │
    │<───── pings (every 15s) ─────────────│  (keep-alive)
    │───── pongs ─────────────────────────>│
    │                                      │
    │<───── commands (list/get/patch) ─────│
    │───── responses ─────────────────────>│

MCP Tools

`tampermonkey_get_connection_code`

Purpose: Initialize connection by getting the WebSocket connection code.
Required: Must be called first to start the WebSocket server.
Output: Connection code to enter in Tampermonkey Editors.

`tampermonkey_list`

Purpose: List all available userscripts.
Input: Optional filter by name pattern or include URL pattern.
Output: Array of userscript metadata (name, namespace, path, requires).

`tampermonkey_get`

Purpose: Get content of a specific userscript.
Input: path (from list), optional ifNotModifiedSince timestamp.
Output: Script content, lastModified timestamp, or error.

`tampermonkey_patch`

Purpose: Update userscript content.
Input: path, value (new content), optional lastModified for optimistic locking.
Output: Success confirmation or error.

`tampermonkey_put`

Purpose: Create a new userscript with the given name and namespace.
Input: value (new script), optional lastModified.
Output: Success confirmation, path of created script, or error.
Requires: Tampermonkey Editors 1.0.6+ and Tampermonkey 5.6+

`tampermonkey_delete`

Purpose: Delete an existing userscript.
Input: path (from list).
Output: Success confirmation or error.
Requires: Tampermonkey Editors 1.0.6+ and Tampermonkey 5.6+

Basic testing

MCP Server capabilities

Terminal

curl -X POST http://localhost:4001/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
      "protocolVersion": "2024-11-05",
      "clientInfo": {
        "name": "curl-client",
        "version": "1.0.0"
      },
      "capabilities": {}
    }
  }'

test stdio

bash

echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","clientInfo":{"name":"test-client","version":"1.0.0"},"capabilities":{}}}' | npx -y tampermonkey-mcp
echo '{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}' | npx -y tampermonkey-mcp
echo '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"tampermonkey_list","arguments":{"pattern":""}}}' | npx -y tampermonkey-mcp

Read the full README →View source on GitHub →

Related MCP Servers

View all in Developer Tools View all alternatives

Adoption & maintenance

Factual signals from GitHub, npm, and our automated checks — not a rating.

GitHub stars

Stargazers on the source repository.

Last commit

2mo ago

Most recent push to the default branch.

Tools exposed

Callable tools this server registers over MCP.

Directory activity

2 views

Config copies, upvotes, and views on AllMCPs.

Reviews

No reviews yet — be the first to share how this listing worked for you.

Frequently Asked Questions about Tampermonkey MCP

Add the following block to your claude_desktop_config.json under mcpServers: "mcpServers": { "tampermonkey-mcp": { "command": "npx", "args": ["-y","tampermonkey-mcp"] } }

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Technical Specs & Signals

CategoryDeveloper Tools

11/12 checks healthy over the last 45d

51Quality signal: Good · 51/100How this signal is calculated ▾

Server availabilityNot measured

Not scored for repo-hosted servers — we can't reach the running server, only its GitHub page. Hosted MCP endpoints are health-checked live.

Verified ownership10/20

Documentation & tools23/30

Adoption & activity5/15

Community engagement0/10

A guidance signal from public completeness & health data — not a user rating. New listings start lower and rise as they add docs, get verified, and grow adoption. Signals we can't observe for a listing are skipped, not counted against it.

Supply-chain signal

No high-severity advisories surfaced by our automated scan.

Critical 0High 0Medium 0Low 0

Scanned 6d ago via OSV.dev · tampermonkey-mcp (npm)

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Explore more

More in 💻 Developer Tools →Best MCP servers for Developers →Alternatives to Tampermonkey MCP →Install in Claude Desktop Install in Cursor Install in VS Code Setup guides for all 13 MCP clients

Tampermonkey MCP

MCP server to manage your Tampermonkey scripts

Quick Install

Automated & IDE Setup

Copy the AI prompt to install this server into Claude Code, Cursor, or another agent — or use 1-click editor setup below.

Add to Cursor Add to VS Code

Not yet automatically verified

We haven't yet run this listing's install command through our automated sandbox check. This isn't a red flag — we're steadily working through the catalog.

Manual Client & Custom JSON ConfigExpand JSON ▾

Client Config & Setup

Choose your client or environment

Target File:~/Library/Application Support/Claude/claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "tampermonkey-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "tampermonkey-mcp"
      ]
    }
  }
}

💡 Paste the JSON block into your client's configuration file under mcpServers, then restart the application.

Capabilities & Tool Schemas (6)Self-reported

Inspect callable tools, capabilities, and parameters exposed to AI agents by Tampermonkey MCP.

tampermonkey_get_connection_code

* **Purpose**: Initialize connection by getting the WebSocket connection code.

tampermonkey_list

* **Purpose**: List all available userscripts.

tampermonkey_get

* **Purpose**: Get content of a specific userscript.

tampermonkey_patch

* **Purpose**: Update userscript content.

tampermonkey_put

* **Purpose**: Create a new userscript with the given name and namespace.

tampermonkey_delete

* **Purpose**: Delete an existing userscript.

Documentation Overview

How to use

First install the following browser extensions:

Tampermonkey
Tampermonkey Editors for Firefox or Chrome

Then install tampermonkey-mcp globally:

Terminal

npm install -g tampermonkey-mcp@latest

Finally configure your AI assistant to use the tampermonkey tool:

JSON Config

{
  "mcpServers": {
    "tampermonkey": {
      "command": "npx",
      "args": [
        "-y",
        "tampermonkey-mcp@latest"
      ]
    }
  }
}

Your assistant will call tampermonkey_get_connection_code and return a connection code that you can enter in the Tampermonkey Editors extension.

Claude Code configuration example

Terminal

npm install -g claude

// either use your local checkout
npm run watch
claude mcp add --transport http --scope project tampermonkey http://localhost:4001/mcp

// or the npm package
npm install -g tampermonkey-mcp@latest
claude mcp add --transport stdio --scope project tampermonkey -- npx -y tampermonkey-mcp

// more browser control needed?
// Open chrome://inspect/#remote-debugging
// [x] Allow remote debugging for this browser instance
// or
chromium --user-data-dir=/tmp/chrome-devtools-mcp-test-profile --remote-debugging-port=9222

npm install -g chrome-devtools-mcp@latest
// install Tampermonkey and Tampermonkey Editors
claude mcp add --transport stdio --scope project chrome-devtools-mcp -- npx -y chrome-devtools-mcp@latest --slim --no-usage-statistics --auto-connect --browser-url http://127.0.0.1:9222

Build

Terminal

npm install
npm run all

Tampermonkey MCP Server Architecture

Overview

This project implements an MCP (Model Context Protocol) server that allows AI assistants to read and modify Tampermonkey userscripts via the Tampermonkey Editors browser extension.

Architecture Components

Code

┌─────────────────────────────────────────────────────────────────────────────┐
│                              AI Assistant                                   │
└─────────────────────────────────────────────────────────────────────────────┘
                                   │
                                   │ MCP Protocol (stdio transport)
                                   ▼
┌─────────────────────────────────────────────────────────────────────────────┐
│                         tampermonkey_mcp (MCP Server)                       │
│                                                                             │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  server.ts                    │  Main entry point                     │  │
│  │                               │  - HTTP or stdio transport            │  │
│  │                               │  - MCP middleware                     │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
│                                  │                                          │
│                                  ▼                                          │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  tampermonkey.ts              │  MCP Tool Definitions                 │  │
│  │                               │  - tampermonkey_get_connection_code   │  │
│  │                               │  - tampermonkey_list                  │  │
│  │                               │  - tampermonkey_get                   │  │
│  │                               │  - tampermonkey_patch                 │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
│                                  │                                          │
│                                  ▼                                          │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  tampermonkey-ws-client.ts    │  WebSocket Server                     │  │
│  │                               │  - Connection code generation         │  │
│  │                               │  - Authentication handshake           │  │
│  │                               │  - Message relay to extension         │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────────────────────┘
                                   │
                                   │ WebSocket (local, port derived from code)
                                   ▼
┌─────────────────────────────────────────────────────────────────────────────┐
│                   Tampermonkey Editors Extension                            │
│                                                                             │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  Service Worker               │  Receives connection code,            │  │
│  │                               │  establishes WebSocket connection     │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
│                                  │                                          │
│                                  │ Chrome Extension Messaging               │
│                                  ▼                                          │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  Content Script               │  Bridges extension ↔ Tampermonkey     │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
│                                  │                                          │
│                                  ▼                                          │
│  ┌───────────────────────────────────────────────────────────────────────┐  │
│  │  Tampermonkey                 │  Userscript storage & execution       │  │
│  └───────────────────────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────────────────────┘

Connection Flow

MCP Server starts - Creates WebSocket server on a random available port
Connection code generated - Format: <base32(port - 1024)><auth_token><echo_token>
User calls tampermonkey_get_connection_code - Gets the connection code
User enters code in Tampermonkey Editors - Extension parses code to get port and auth
Extension connects to MCP server - WebSocket handshake with authentication
MCP tools become available - list, get, patch can now be called

Authentication Protocol

Code

Extension                              MCP Server
    │                                      │
    │───── auth (token) ──────────────────>│
    │                                      │
    │<──── auth (echo_token) ──────────────│
    │                                      │
    │───── auth (echo_token) ─────────────>│
    │                                      │
    │<──── authOK ─────────────────────────│
    │                                      │
    │<───── pings (every 15s) ─────────────│  (keep-alive)
    │───── pongs ─────────────────────────>│
    │                                      │
    │<───── commands (list/get/patch) ─────│
    │───── responses ─────────────────────>│

MCP Tools

`tampermonkey_get_connection_code`

Purpose: Initialize connection by getting the WebSocket connection code.
Required: Must be called first to start the WebSocket server.
Output: Connection code to enter in Tampermonkey Editors.

`tampermonkey_list`

Purpose: List all available userscripts.
Input: Optional filter by name pattern or include URL pattern.
Output: Array of userscript metadata (name, namespace, path, requires).

`tampermonkey_get`

Purpose: Get content of a specific userscript.
Input: path (from list), optional ifNotModifiedSince timestamp.
Output: Script content, lastModified timestamp, or error.

`tampermonkey_patch`

Purpose: Update userscript content.
Input: path, value (new content), optional lastModified for optimistic locking.
Output: Success confirmation or error.

`tampermonkey_put`

Purpose: Create a new userscript with the given name and namespace.
Input: value (new script), optional lastModified.
Output: Success confirmation, path of created script, or error.
Requires: Tampermonkey Editors 1.0.6+ and Tampermonkey 5.6+

`tampermonkey_delete`

Purpose: Delete an existing userscript.
Input: path (from list).
Output: Success confirmation or error.
Requires: Tampermonkey Editors 1.0.6+ and Tampermonkey 5.6+

Basic testing

MCP Server capabilities

Terminal

curl -X POST http://localhost:4001/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "initialize",
    "params": {
      "protocolVersion": "2024-11-05",
      "clientInfo": {
        "name": "curl-client",
        "version": "1.0.0"
      },
      "capabilities": {}
    }
  }'

test stdio

bash

echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","clientInfo":{"name":"test-client","version":"1.0.0"},"capabilities":{}}}' | npx -y tampermonkey-mcp
echo '{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}' | npx -y tampermonkey-mcp
echo '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"tampermonkey_list","arguments":{"pattern":""}}}' | npx -y tampermonkey-mcp

Read the full README →View source on GitHub →

Related MCP Servers

View all in Developer Tools View all alternatives

Adoption & maintenance

Factual signals from GitHub, npm, and our automated checks — not a rating.

GitHub stars

Stargazers on the source repository.

Last commit

2mo ago

Most recent push to the default branch.

Tools exposed

Callable tools this server registers over MCP.

Directory activity

2 views

Config copies, upvotes, and views on AllMCPs.

Reviews

No reviews yet — be the first to share how this listing worked for you.

Frequently Asked Questions about Tampermonkey MCP

Add the following block to your claude_desktop_config.json under mcpServers: "mcpServers": { "tampermonkey-mcp": { "command": "npx", "args": ["-y","tampermonkey-mcp"] } }

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Showcase your server listing on GitHub or your project documentation. Embed this dynamic SVG badge to highlight official listing status and live engagement.

Badge Style:

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Markdown (GitHub README)

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<a href="https://allmcps.com/mcp/tampermonkey-mcp"><img src="https://allmcps.com/api/badge/tampermonkey-mcp?style=directory" alt="Tampermonkey MCP on AllMCPs" /></a>

Technical Specs & Signals

CategoryDeveloper Tools

11/12 checks healthy over the last 45d

51Quality signal: Good · 51/100How this signal is calculated ▾

Server availabilityNot measured

Not scored for repo-hosted servers — we can't reach the running server, only its GitHub page. Hosted MCP endpoints are health-checked live.

Verified ownership10/20

Documentation & tools23/30

Adoption & activity5/15

Community engagement0/10

Supply-chain signal

No high-severity advisories surfaced by our automated scan.

Critical 0High 0Medium 0Low 0

Scanned 6d ago via OSV.dev · tampermonkey-mcp (npm)

★ Spotlight Slot

Feature Your MCP Server

Get maximum visibility for your server across our directory, search results, and detail pages.

Spotlight Your Server

Own this project?

Free dofollow backlink: add your website and place the AllMCPs badge on it — no claim needed. We detect it automatically and keep it verified as long as the badge stays live.

Claim & get free dofollow

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