garak is NVIDIA's open-source LLM vulnerability scanner for red-teaming AI models and applications. Probes for prompt injection, data leakage, hallucination, toxicity, encoding-based attacks, and dozens of other vulnerability categories. Runs automated attack sequences against any LLM endpoint and generates detailed vulnerability reports. Features a modular probe/detector architecture that is extensible with custom attack patterns. Named after the Star Trek character known for deception.
Best Shannon Alternatives
5 editor-verified alternatives · Shannon overview →
source: tools.alternatives · stored order · active records only; review scores are annotations and never change membership or order
Guardrails AI is an open-source Python and JavaScript framework for validating and structuring LLM outputs using composable Guards built from a Hub of pre-built validators. It handles structured data extraction with Pydantic models, content safety checks including toxicity, PII detection, competitor mentions, and bias filtering, plus automatic re-prompting when validation fails. The Guardrails Hub offers dozens of validators from regex matching to hallucination detection via LLM judges.
LLM Guard is an open-source security toolkit by Protect AI that provides 15 input scanners and 20 output scanners to protect LLM applications from prompt injection, PII leakage, toxic content, secrets exposure, and data exfiltration. Each scanner is modular and independent — pick the ones you need, configure thresholds, and chain them into a pipeline. The library works with any LLM and has been downloaded over 2.5 million times. MIT licensed, Python 3.9+.
Agentic Radar is an open-source CLI security scanner that maps attack surfaces in agentic AI workflows. It detects MCP servers, visualizes agent tool chains, and validates against OWASP LLM Top 10 vulnerabilities including prompt injection and excessive agency. Supports scanning CrewAI, LangGraph, AutoGen, and Semantic Kernel pipelines. Built by SPLX AI with active development and MCP-specific detection capabilities added for the growing MCP ecosystem.
OSV-Scanner is Google's official open-source vulnerability scanner that checks your project's dependencies against the OSV.dev database — the largest open vulnerability database covering all major ecosystems. Written in Go, it supports lockfiles from npm, pip, Maven, Cargo, Go modules, and more, providing actionable remediation guidance and CI/CD integration for automated security scanning.
Open-source Shannon alternatives
garak, LLM Guard, Agentic Radar, osv-scanner — see all open-source developer tools.
Free Shannon alternatives
Guardrails AI offer a free plan or free tier.
Shannon head-to-head
FAQ
What is the best Shannon alternative?
garak tops our editor-verified list of 5 Shannon alternatives.
Are there open-source Shannon alternatives?
Yes — garak, LLM Guard, Agentic Radar, and more are open source.
Are there free Shannon alternatives?
Yes — Guardrails AI offer a free plan or free tier.