mcpField
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Bawbel Scanner

Bawbel Scanner

Local
github.com/bawbelSecurity2Updated 1w ago

About Bawbel Scanner

Bawbel Scanner is an MCP server for scanning MCP servers and agent files for vulnerabilities. It also checks spec conformance and provides searchable AVE threat records and suppression tracking.

Key features

  1. 01Scan content, server cards, credentials, and delegation chains
  2. 02Score MCP spec conformance
  3. 03Manage justified finding suppressions
  4. 04Search and retrieve AVE threat records
  5. 05Detect drift in skill files

Use cases

  1. 01Check a server card before connecting
  2. 02Audit skill files for secrets or unsafe delegation
  3. 03Review conformance failures and AVE remediation
  4. 04Record a reviewed false positive

MCP support

Exposes scanning, conformance, suppression, and AVE lookup tools to MCP clients, plus AVE statistics and record resources.

Configuration

Local server config is the same for every client. Copy it into your client’s MCP config file.

mcp.json · Universal config
{
"mcpServers": {
"bawbel-bawbel": {
"command": "uvx",
"args": [
"bawbel-mcp"
]
}
}
}
Run commanduvx bawbel-mcp

Local servers need a runtime on your machine (e.g. Node.js 18+). Config file locations differ by client; see your client’s docs.

Packages
pypibawbel-mcp1.1.0

Tools

10

Saved tool list · updated 2w ago

ParameterTypeRequiredDescription
labelstringNoOptional label for the content in the output
contentstringYesThe text content to scan (skill file, system prompt, etc.)
no_ignorebooleanNoIf True, bypass all suppressions and show every finding

Details

From the project README

Bawbel MCP Server

Security scanner for MCP servers and agentic AI components, exposed as MCP tools.

Bawbel MCP Server lets any MCP-compatible agent scan servers, check skill files, score conformance, manage justified suppressions, and query the AVE threat intelligence database mid-conversation.

PyPI version PyPI - Python Version PyPI - Downloads License AVE Standard MCP Compatible Powered by


Install

pip install bawbel-mcp

Or with all detection engines (YARA, Semgrep, LLM, Magika, Sandbox):

pip install "bawbel-mcp[all]"

Tools

ToolDescription
scan_contentScan raw text content for AVE vulnerabilities
scan_server_cardFetch and scan an MCP server-card before connecting
scan_credsCredential-focused scan (API keys, tokens, passwords, private keys)
scan_chainDelegation chain scan (unsafe sub-agent spawning and inherited permissions)
check_conformanceScore a server manifest against the MCP spec (18 checks, A+ to F)
accept_findingInsert a justified suppression with reason, reviewer, and optional expiry
lookup_aveGet a full AVE record by ID with remediation guidance
search_aveSearch AVE records by keyword
list_aveList all AVE records with optional severity/category filters
check_pinsDetect rug pull drift in a directory of skill files

Resources

ResourceDescription
ave://statsCurrent AVE database statistics
ave://record/{ave_id}Full AVE record for a specific ID

Usage

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "bawbel": {
      "command": "uvx",
      "args": ["bawbel-mcp"]
    }
  }
}
Claude Code
claude mcp add bawbel uvx bawbel-mcp
Cursor / Windsurf

Add to your MCP settings:

{
  "bawbel": {
    "command": "uvx",
    "args": ["bawbel-mcp"]
  }
}
Remote deployment (Streamable HTTP)
uvx bawbel-mcp --transport streamable-http --host 0.0.0.0 --port 8000

Example conversations

Scan a server before connecting:

"Before I add this MCP server to my config, scan it for security issues: https://api.some-mcp-server.com"

Claude calls scan_server_card("https://api.some-mcp-server.com") and reports findings with AVE IDs, AIVSS severity scores, and remediation steps.

Check a skill file:

"Check this skill file content for prompt injection vulnerabilities"

Claude calls scan_content(content) and returns findings including any toxic flow chains detected.

Check for hardcoded credentials:

"Does this skill file contain any hardcoded API keys or secrets?"

Claude calls scan_creds(content) and returns credential findings only.

Check for unsafe delegation:

"Does this skill spawn sub-agents without proper trust boundaries?"

Claude calls scan_chain(content) and returns delegation chain findings.

Accept a false positive:

"Mark AVE-2026-00001 on line 7 of travel.md as a false positive. Reason: internal registry endpoint, not attacker-controlled."

Claude calls accept_finding(...) and writes the justified suppression comment directly into the file. The approval is tracked in version control.

Score a server against the spec:

"Does this server follow the MCP spec? https://api.some-mcp-server.com"

Claude calls check_conformance("https://api.some-mcp-server.com") and returns a score, grade, and list of failed checks.

Look up a vulnerability:

"What is AVE-2026-00041 and how do I fix it?"

Claude calls lookup_ave("AVE-2026-00041") and returns the full record with behavioral fingerprint, IOCs, and remediation steps.

Search for relevant vulnerabilities:

"What AVE records cover credential exfiltration?"

Claude calls search_ave("credential exfiltration") and returns matching records with AIVSS scores and OWASP MCP categories.

Audit mode - see all findings including suppressed:

"Scan this file and show me everything, including suppressed findings."

Claude calls scan_content(content, no_ignore=True) and bypasses all suppression layers.


Requirements

  • Python 3.10+
  • bawbel-scanner>=1.2.2 (installed automatically)
  • fastmcp>=3.0.0 (installed automatically)

The bawbel CLI must be available in PATH. Installing bawbel-mcp installs bawbel-scanner which provides the bawbel CLI.


Related


Apache 2.0. Built by Bawbel.

Comments

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New to MCP?

From what the protocol is to installing your first server, these answers cover most first questions.

An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.