io.github.mcpcustoms/mcp-customs (MCP Custom s)

The io.github.mcpcustoms/mcp-customs server provides a way to inspect an MCP server for common security risks prior to installation. It is designed to run offline and uses zero telemetry, focusing on security review of an MCP server before deployment.

🛠️ Key Features

Inspects an MCP server for common security risks before installation
Offline operation
Zero telemetry

🚀 Use Cases

Pre-install security review of MCP servers
Assessing common risk patterns in third-party MCP server software

⚡ Developer Benefits

Supports risk checking workflow for MCP server adoption
Avoids telemetry collection during inspection

⚠️ Limitations

No additional capabilities beyond “inspect for common security risks,” based on the provided description

mcp-customs

Inspect an MCP server for common security risks before you install it. Runs fully offline. No telemetry, no cloud upload, no account.

code

npx mcp-customs scan ./some-mcp-server

code

──────────────────────────────────────────────────────
MCP-CUSTOMS INSPECTION REPORT
──────────────────────────────────────────────────────
target        ./some-mcp-server
files scanned 14
score         62 / 100
stamp         [ REVIEW ]
──────────────────────────────────────────────────────
[HIGH] MCP002 — Unsanitized file path (possible path traversal)
  server.js:41  return fs.readFileSync(userPath, 'utf8');
  fix: Resolve the path against an allowed base directory ...

Why

Developers install MCP servers the way they used to install npm packages — quickly, trusting the name, and moving on. An MCP server can read your files, call your APIs, and execute commands on your behalf. Almost nobody checks what it can actually do before connecting it to their agent.

mcp-customs is the "audit before install" step, run locally, in seconds.

What it checks (v0.1)

Rule

Severity

What it looks for

MCP001

critical

Shell command execution with unsanitized interpolation

MCP002

high

File reads/writes without a path-traversal guard

MCP003

critical

eval() / dynamic code execution

MCP004

high

Hardcoded API keys / credentials

MCP005

critical

Tool descriptions containing hidden-instruction language (prompt injection via the tool's own metadata)

MCP006

medium

Outbound network calls combined with environment-variable reads (possible exfiltration)

MCP007

low

No permissions/scopes declared in the manifest

These are heuristic, regex-based checks — fast and fully auditable in one sitting, not a dataflow analysis. They will produce false positives and will miss things a deeper analysis would catch. Treat a CLEARED stamp as "nothing obvious," not "verified safe."

MCP Customs

io.github.mcpcustoms/mcp-customs (MCP Custom s)

🛠️ Key Features

🚀 Use Cases

⚡ Developer Benefits

⚠️ Limitations

mcp-customs

Why

What it checks (v0.1)

CI usage

Get a badge for your README

Roadmap

License

Install