Model Context Protocol moderate risk

JS

Executes JavaScript code in a V8 engine with optional heap persistence via S3 or local storage, offering flexible integration with AI agents.

Connections & Capabilities

Connects To

FilesystemAWSS3

Capabilities

execreadwrite

Quickstart

Config

{
  "mcpServers": {
    "js": {
      "command": "/usr/local/bin/mcp-v8 --s3-bucket my-bucket-name"
    }
  }
}

Exposed MCP Tools (1)

high

JavaScript Execution

Executes arbitrary JavaScript code within a V8 engine.

Unrestricted code execution can lead to various security risks.

Safety Assessment

The server's safety depends on the chosen mode and storage. Stateless mode is safer due to its ephemeral nature. Stateful mode, especially with S3, requires careful credential management and awareness of the risks associated with persistent JavaScript execution.

V8 engine provides a degree of isolation.
Stateless mode eliminates persistent state risks.
Clear limitations on available JavaScript APIs (no network, file system access).
Heap snapshots can be stored locally or in S3, allowing for controlled persistence.

Arbitrary JavaScript execution poses inherent risks.
Stateful mode introduces potential for persistent malicious code.
S3 storage requires careful management of AWS credentials.
Lack of `async/await` could lead to blocking operations.