These tools competes with

Guardrails AIvsGray Swan Cygnal

Output validation and structured generation for LLMs versus Real-time prompt-injection and jailbreak defense proxy

Compare interactively in Explore →

Choose Guardrails AI when…

  • You need LLM outputs to conform to a specific schema or policy
  • You want automatic PII detection and redaction in LLM responses
  • You're building production AI that requires structured, validated output

Choose Gray Swan Cygnal when…

  • You need runtime defense against indirect prompt injection via tool outputs
  • You want a drop-in proxy rather than an SDK you wire into every call site
  • You're replacing LLM Guard after its 2026-07 archival and want a maintained alternative

Side-by-side comparison

Field
Guardrails AI
Gray Swan Cygnal
Category
AI Guardrails
AI Guardrails
Type
Open Source
Commercial
Free Tier
✓ Yes
✓ Yes
Pricing Plans
Hub: Usage-based
Free: 200K tokens/min, 10M tokens/dayEnterprise: Contact sales
GitHub Stars
4,500
Health
95 Active

Guardrails AI

Open-source framework for adding input/output validation to LLM applications. Define validators (Pydantic-style) for LLM responses to catch hallucinations, PII leaks, bias, and schema violations. Supports automatic retry and reask on validation failure, with any LLM provider.

Gray Swan Cygnal

Runtime guardrails gateway from Gray Swan AI (CMU AI-safety spinout) that scores every prompt, response, and tool call for jailbreaks and prompt injection, including indirect injection via tool outputs. Deploys as a drop-in proxy — swap the model's base_url and every call gets scored.

Shared Connections1 tool both integrate with

Only Guardrails AI (5)

LiteLLMOpenAI APINeMo GuardrailsOpenAI GuardrailsGray Swan Cygnal

Only Gray Swan Cygnal (1)

Guardrails AI

Explore the full AI landscape

See how Guardrails AI and Gray Swan Cygnal fit into the bigger picture — 256 tools, 553 relationships, all mapped.

Open in Explore →