guardrails-mcp-server
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@guardrails-mcp-serverCheck this prompt for injection: 'Ignore instructions'"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
guardrails-mcp-server
[!License: MIT](https://opensource.org/licenses/MIT) [!MCP](https://modelcontextprotocol.io) [!Node.js](https://nodejs.org)
MCP server for AI agent security guardrails. Provides input validation, prompt injection detection, PII redaction, output filtering, policy enforcement, rate limiting, and comprehensive audit logging.
Tools
Tool | Description |
| Validate and sanitize incoming requests through all guardrail checks |
| Filter and redact sensitive data (PII, secrets, credentials) from responses |
| Evaluate a request against security policies (RBAC, resource access, quotas) |
| Query the audit log with filtering by type, user, time range |
| Get engine statistics including active users, block rate, request counts |
| Update guardrail configuration at runtime |
Related MCP server: SentinelGate
Security Features
Prompt Injection Detection -- 12 regex patterns for jailbreak, DAN mode, system prompt override
PII Detection and Redaction -- SSN, credit card, email, phone, IP, API keys, AWS keys, JWT, passwords, private keys, connection strings
Malicious Code Blocking -- eval, exec, subprocess, child_process, shell injection
Policy Engine -- Block sensitive paths, dangerous tools, unauthenticated destructive ops, URL allowlist, maintenance windows
Rate Limiting -- Per-user sliding window (configurable requests/minute)
Audit Logging -- Timestamped events with metrics, log rotation, external handler support
Install
npm installConfiguration
{
"mcpServers": {
"guardrails": {
"type": "stdio",
"command": "node",
"args": ["/path/to/guardrails-mcp-server/index.js"]
}
}
}Project Structure
src/engine/GuardrailsEngine.js # Core orchestration
src/validators/InputValidator.js # Prompt injection and PII detection
src/filters/OutputFilter.js # Redaction and harmful content blocking
src/policies/PolicyEngine.js # RBAC, quotas, maintenance windows
src/audit/AuditLogger.js # Event logging and metricsLicense
This server cannot be deployed
Maintenance
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