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.

Install

pip install bawbel-mcp

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

pip install "bawbel-mcp[all]"

Tools

Tool	Description
`scan_content`	Scan raw text content for AVE vulnerabilities
`scan_server_card`	Fetch and scan an MCP server-card before connecting
`scan_creds`	Credential-focused scan (API keys, tokens, passwords, private keys)
`scan_chain`	Delegation chain scan (unsafe sub-agent spawning and inherited permissions)
`check_conformance`	Score a server manifest against the MCP spec (18 checks, A+ to F)
`accept_finding`	Insert a justified suppression with reason, reviewer, and optional expiry
`lookup_ave`	Get a full AVE record by ID with remediation guidance
`search_ave`	Search AVE records by keyword
`list_ave`	List all AVE records with optional severity/category filters
`check_pins`	Detect rug pull drift in a directory of skill files

Resources

Resource	Description
`ave://stats`	Current 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.

bawbel-scanner - CLI scanner
bawbel/ave - AVE standard and records
api.piranha.bawbel.io - Threat intel API
bawbel.io/docs - Full documentation

Apache 2.0. Built by Bawbel.

Bawbel Scanner