Is Assay MCP Server safe to use?

Assay MCP Server has 2 known CVEs tracked by MCPpedia. You can verify these on OSV.dev by searching for "@modelcontextprotocol/server-filesystem". Review the Security section above for details before installing.

How do I install Assay MCP Server?

Assay MCP Server supports copy-paste install configs on its MCPpedia page for Claude Desktop, Cursor, and Claude Code. Scroll to the Quick Install section and select your client.

What AI clients work with Assay MCP Server?

Assay MCP Server is compatible with claude-desktop, cursor, claude-code. It uses stdio and sse and http transport.

Is Assay MCP Server actively maintained?

Assay MCP Server is actively maintained — last commit was 1 day ago. It has 7 GitHub stars.

Assay MCP Server

@modelcontextprotocol/server-filesystem

The firewall for MCP tool calls. Block, audit, replay with evidence bundles.

7 390.7k/wk GitHub npm PyPI

2 open CVEs

No license

Actively maintained

Last commit 1d ago

Works with most clients

Transport: stdio, sse, http

0 tools

Grade F

Edit this pageView history

Security

Step 1

Install in your client

Config is the same across clients — only the file and path differ.

Supported in Claude Desktopstdio, sse, http · Node 18+

Paste into ~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "io-github-rul1an-assay": {
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem"
      ],
      "command": "npx"
    }
  }
}

Are you the author?

Add this badge to your README to show your security score and help users find safe servers.

Embed in your READMEAbout badges →

[![MCPpedia Score](https://mcppedia.org/api/badge/io-github-rul1an-assay)](https://mcppedia.org/s/io-github-rul1an-assay)

Read me

What Assay MCP Server does

Your MCP agent calls read_file, exec, web_search — but should it, and what can you honestly prove about that run afterward?

Test This Server

Run this in your terminal to verify the server starts. Then let us know if it worked — your result helps other developers.

npx -y '@modelcontextprotocol/server-filesystem' 2>&1 | head -1 && echo "✓ Server started successfully"

After testing, let us know if it worked:

Loading README…

Scored, not listed

Why this score

Five weighted categories — click any category to see the underlying evidence.

Score breakdown

61/100across 5 weighted dimensions

How we score →

0255075100

−39

Security

Maintenance

Efficiency

Documentation

Compatibility

Categoriesclick a row to see evidence

Security

OSV.dev

2 open

CVE-2025-53110info

@modelcontextprotocol/server-filesystem vulnerability allows for path validation bypass via colliding path prefix

Versions of Filesystem prior to 0.6.3 & 2025.7.1 could allow access to unintended files in cases where the prefix matches an allowed directory. Users are advised to upgrade to 2025.7.1 to resolve the issue. Thank you to Elad Beber (Cymulate) for reporting these issues.

Affected: >= 0source →

CVE-2025-53109info

@modelcontextprotocol/server-filesystem allows for path validation bypass via prefix matching and symlink handling

Versions of Filesystem prior to 0.6.3 & 2025.7.1 could allow access to unintended files via symlinks within allowed directories. Users are advised to upgrade to 2025.7.1 to resolve. Thank you to Elad Beber (Cymulate) for reporting these issues.

Affected: >= 0source →

Community

Reviews

Be the first to review

Have you used this server?

Share your experience — it helps other developers decide.

How easy was setup?Did it work reliably?How was the documentation?

Frequently Asked Questions

Is Assay MCP Server safe to use?: Assay MCP Server has 2 known CVEs tracked by MCPpedia. You can verify these on OSV.dev by searching for "@modelcontextprotocol/server-filesystem". Review the Security section above for details before installing.
How do I install Assay MCP Server?: Assay MCP Server supports copy-paste install configs on its MCPpedia page for Claude Desktop, Cursor, and Claude Code. Scroll to the Quick Install section and select your client.
What AI clients work with Assay MCP Server?: Assay MCP Server is compatible with claude-desktop, cursor, claude-code. It uses stdio and sse and http transport.
Is Assay MCP Server actively maintained?: Assay MCP Server is actively maintained — last commit was 1 day ago. It has 7 GitHub stars.

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Community

Discussion

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Has anyone used this with Cursor?How do you handle auth?Any alternatives?

Edit this pageView history

Security

Step 1

Install in your client

Config is the same across clients — only the file and path differ.

Supported in Claude Desktopstdio, sse, http · Node 18+

Paste into ~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "io-github-rul1an-assay": {
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem"
      ],
      "command": "npx"
    }
  }
}

Are you the author?

Add this badge to your README to show your security score and help users find safe servers.

Embed in your READMEAbout badges →

[![MCPpedia Score](https://mcppedia.org/api/badge/io-github-rul1an-assay)](https://mcppedia.org/s/io-github-rul1an-assay)

Read me

What Assay MCP Server does

Your MCP agent calls read_file, exec, web_search — but should it, and what can you honestly prove about that run afterward?

Test This Server

Run this in your terminal to verify the server starts. Then let us know if it worked — your result helps other developers.

npx -y '@modelcontextprotocol/server-filesystem' 2>&1 | head -1 && echo "✓ Server started successfully"

After testing, let us know if it worked:

README

Assay

Policy-as-code for MCP agents: enforce what a tool call can do, prove what it did, stay honest about what you can't.
A deterministic, fail-closed gate for MCP tool calls — with real kernel-level (eBPF/LSM) enforcement on Linux and offline-verifiable evidence. CI-native, no backend, bounded by design.

Quickstart · How it works · See it work · MCP example · OWASP MCP Top 10 · Discussions

Agents got real tool access through MCP — and tool poisoning, rug pulls, and confused-deputy OAuth came with it. Most tools scan a server or filter a prompt. Assay sits at the tool-call boundary and does three things, in order.

Enforce, prove, stay honest

Enforce. A deterministic, fail-closed gate decides every tools/call before it runs, with the precise reason for each allow or deny. On Linux it adds real kernel enforcement — an eBPF/LSM IPv4/TCP connect-egress block and a Landlock TCP-connect port allowlist, both opt-in and fail-closed. A policy it cannot express exactly is refused, never half-applied.
Prove. Each decision and observed effect becomes an offline-verifiable, tamper-evident evidence bundle: the verdict, the pre-call establish journey, and declared-vs-observed conformance — all reviewable in CI, with no hosted backend.
Stay honest. Every claim carries its basis (verified, self_reported, inferred, absent), and a gate refuses to let a claim exceed what was observed. A tool returning "success" is the provider's assertion, never proof. Assay ships no single safety score and never claims more than it can prove.

Quickstart

cargo install assay-cli

mkdir -p /tmp/assay-demo && echo "safe content" > /tmp/assay-demo/safe.txt
assay mcp wrap --policy examples/mcp-quickstart/policy.yaml \
  -- npx @modelcontextprotocol/server-filesystem /tmp/assay-demo

✅ ALLOW  read_file  path=/tmp/assay-demo/safe.txt  reason=policy_allow
❌ DENY   read_file  path=/tmp/outside-demo.txt      reason=path_constraint_violation
❌ DENY   exec       cmd=ls                          reason=tool_denied

Wire it into Cursor, Claude Code, or Codex in one line with assay mcp config-path <editor>. Python SDK: pip install assay-it. CI: GitHub Action. No hosted backend, no API keys for core flows, deterministic by design. New to the threat model? The OWASP MCP Top 10 mapping lays out, per risk, what Assay covers and what it deliberately does not.

What ships

Output	What it is
Policy gate	`assay mcp wrap` — deterministic allow/deny before tools run, with the reason.
Evidence bundle	Offline-verifiable, tamper-evident archive for audit and replay.
Trust Basis / Trust Card	Canonical `trust-basis.json` (bounded claim classification) plus review-friendly `trustcard.{json,md,html}`.
External receipts	Eval outcomes, runtime decisions, and mod

... View full README on GitHub

Loading README…

Scored, not listed

Why this score

Five weighted categories — click any category to see the underlying evidence.

Score breakdown

61/100across 5 weighted dimensions

How we score →

0255075100

−39

Security

Maintenance

Efficiency

Documentation

Compatibility

Categoriesclick a row to see evidence

Security

OSV.dev

2 open

CVE-2025-53110info

@modelcontextprotocol/server-filesystem vulnerability allows for path validation bypass via colliding path prefix

Affected: >= 0source →

CVE-2025-53109info

@modelcontextprotocol/server-filesystem allows for path validation bypass via prefix matching and symlink handling

Affected: >= 0source →

Community

Reviews

Be the first to review

Have you used this server?

Share your experience — it helps other developers decide.

How easy was setup?Did it work reliably?How was the documentation?

Frequently Asked Questions

Is Assay MCP Server safe to use?: Assay MCP Server has 2 known CVEs tracked by MCPpedia. You can verify these on OSV.dev by searching for "@modelcontextprotocol/server-filesystem". Review the Security section above for details before installing.
How do I install Assay MCP Server?: Assay MCP Server supports copy-paste install configs on its MCPpedia page for Claude Desktop, Cursor, and Claude Code. Scroll to the Quick Install section and select your client.
What AI clients work with Assay MCP Server?: Assay MCP Server is compatible with claude-desktop, cursor, claude-code. It uses stdio and sse and http transport.
Is Assay MCP Server actively maintained?: Assay MCP Server is actively maintained — last commit was 1 day ago. It has 7 GitHub stars.