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.
Alternatives to Shannon
5 editor-selected alternatives · Shannon overview →
source: tools.alternatives · stored order · active records only; review scores are annotations and never change membership or order
A directional evidence panel appears only when the substitute rationale, trade-offs, sources, and verification date have been recorded. Older selections without that panel remain visible but are unclassified under the new evidence contract.
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, Guardrails AI, LLM Guard, Agentic Radar, osv-scanner — see all open-source developer tools.
Free Shannon alternatives
More AI Security & DevSecOps tools
same category, not editor-selected alternatives — see how Shannon compares →
Shannon head-to-head
FAQ
Which Shannon alternative is listed first?
garak is first in the editor-selected list of 5 Shannon alternatives. The stored order is editorial; review scores do not determine membership or position.
Are there open-source Shannon alternatives?
Yes — garak, Guardrails AI, LLM Guard, and more are open source.
Are there free Shannon alternatives?
Yes — garak, LLM Guard offer a free plan or free tier.