--- title: "last_layer vs fast-llm-security-guardrails" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/arekusandr-last-layer-vs-zenguard-ai-fast-llm-security-guardrails" tools: ["arekusandr-last-layer", "zenguard-ai-fast-llm-security-guardrails"] --- # last_layer vs fast-llm-security-guardrails *GraphCanon updated Sep 20, 2026* ## Verdict Pick last_layer if an ultra-fast Python tool for detecting prompt injections and jailbreak attempts in large language models suitable for projects requiring rapid security evaluations, with low-latency performance; pick fast-llm-security-guardrails if fast-llm-security-guardrails, also known as ZenGuard, is designed for the rapid deployment of security measures into AI agent systems to ensure they operate within defined trust constraints. [last_layer](https://vibe-eval.com) reports 133 GitHub stars, 6 forks, and 13 open issues, last pushed Jul 26, 2024. [fast-llm-security-guardrails](https://zenguard.ai/) has 155 stars, 21 forks, and 0 open issues, last pushed Feb 3, 2026. Figures are from public GitHub metadata via [last_layer's repository](https://github.com/arekusandr/last_layer) and [fast-llm-security-guardrails's repository](https://github.com/ZenGuard-AI/fast-llm-security-guardrails). | | [last_layer](/tools/arekusandr-last-layer.md) | [fast-llm-security-guardrails](/tools/zenguard-ai-fast-llm-security-guardrails.md) | | --- | --- | --- | | Tagline | Ultra-fast low latency LLM prompt injection jailbreak detection | The fastest Trust Layer for AI Agents | | Stars | 133 | 155 | | Forks | 6 | 21 | | Open issues | 13 | 0 | | Language | Python | Python | | Adopt for | An ultra-fast Python tool for detecting prompt injections and jailbreak attempts in large language models suitable for projects requiring rapid security evaluations, with low-latency performance. | fast-llm-security-guardrails, also known as ZenGuard, is designed for the rapid deployment of security measures into AI agent systems to ensure they operate within defined trust constraints. | | Persona | - | - | | Runtime | - | - | | License | MIT | MIT | | Categories | Evaluation & Observability | AI Agents, Evaluation & Observability | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [last_layer](/tools/arekusandr-last-layer.md) | [fast-llm-security-guardrails](/tools/zenguard-ai-fast-llm-security-guardrails.md) | | --- | --- | --- | | Maintenance | Dormant (18%) | Slowing (36%) | | Days since push | 780d | 222d | | Open issues (now) | 13 | 0 | | Stars delta | +2 (30d) | +1 (30d) | | Owner type | User | Organization | | Full report | [trust report](/tools/arekusandr-last-layer/trust.md) | [trust report](/tools/zenguard-ai-fast-llm-security-guardrails/trust.md) | ## Shared compatibility - **Python**: [last_layer](/tools/arekusandr-last-layer.md) - Python runtime; [fast-llm-security-guardrails](/tools/zenguard-ai-fast-llm-security-guardrails.md) - Python runtime ## Decision facts: last_layer - **Adopt for:** An ultra-fast Python tool for detecting prompt injections and jailbreak attempts in large language models suitable for projects requiring rapid security evaluations, with low-latency performance. ## Decision facts: fast-llm-security-guardrails - **Adopt for:** fast-llm-security-guardrails, also known as ZenGuard, is designed for the rapid deployment of security measures into AI agent systems to ensure they operate within defined trust constraints. ## Choose when ### Choose last_layer if… - Tags unique to last_layer: chatgpt-prompts, jailbreak, large-language-models, llm-local. - When you need fast detection of potential security vulnerabilities due to unauthorized prompt manipulations in real-time scenarios involving LLMs ### Choose fast-llm-security-guardrails if… - Tags unique to fast-llm-security-guardrails: agentic-ai, ai-agent, ai-agents, ai-runtime. - Also covers AI Agents. - Fast integration of privacy and security guardrails in environments where real-time evaluation and observability are critical. ## When NOT to use last_layer - If your application does not require ultra-low latency detection and can afford slower, potentially more comprehensive security evaluations - For environments that prefer a broader range of security features beyond prompt injection detection, as last_layer focuses specifically on this aspect with speed in mind ## When NOT to use fast-llm-security-guardrails - If your project requires a more customizable solution than what fast-llm-security-guardrails offers in its out-of-the-box configurations. - For teams that operate without established runtime environments like LangChain or LlamaIndex, as this may necessitate significant adaptation of ZenGuard. ## Common questions ### What is the difference between last_layer and fast-llm-security-guardrails? last_layer: Ultra-fast low latency LLM prompt injection jailbreak detection. fast-llm-security-guardrails: The fastest Trust Layer for AI Agents. See the comparison table for live GitHub stats and shared categories. ### When should I choose last_layer over fast-llm-security-guardrails? Choose last_layer over fast-llm-security-guardrails when Tags unique to last_layer: chatgpt-prompts, jailbreak, large-language-models, llm-local; When you need fast detection of potential security vulnerabilities due to unauthorized prompt manipulations in real-time scenarios involving LLMs. ### When should I choose fast-llm-security-guardrails over last_layer? Choose fast-llm-security-guardrails over last_layer when Tags unique to fast-llm-security-guardrails: agentic-ai, ai-agent, ai-agents, ai-runtime; Also covers AI Agents; Fast integration of privacy and security guardrails in environments where real-time evaluation and observability are critical. ### When should I avoid last_layer? If your application does not require ultra-low latency detection and can afford slower, potentially more comprehensive security evaluations For environments that prefer a broader range of security features beyond prompt injection detection, as last_layer focuses specifically on this aspect with speed in mind ### When should I avoid fast-llm-security-guardrails? If your project requires a more customizable solution than what fast-llm-security-guardrails offers in its out-of-the-box configurations. For teams that operate without established runtime environments like LangChain or LlamaIndex, as this may necessitate significant adaptation of ZenGuard. ### Is last_layer or fast-llm-security-guardrails more popular on GitHub? fast-llm-security-guardrails has more GitHub stars (155 vs 133). Stars measure visibility, not whether either tool fits your constraints. ### Are last_layer and fast-llm-security-guardrails open source? Yes - both are open-source projects on GitHub (last_layer: MIT, fast-llm-security-guardrails: MIT). ### Where can I find alternatives to last_layer or fast-llm-security-guardrails? GraphCanon lists graph-backed alternatives at [last_layer alternatives](/tools/arekusandr-last-layer/alternatives) and [fast-llm-security-guardrails alternatives](/tools/zenguard-ai-fast-llm-security-guardrails/alternatives) ([last_layer markdown twin](/tools/arekusandr-last-layer/alternatives.md), [fast-llm-security-guardrails markdown twin](/tools/zenguard-ai-fast-llm-security-guardrails/alternatives.md)), ranked by typed relationship edges rather than popularity votes. ### Is there a machine-readable version of this comparison? Yes. The markdown twin at [this comparison](/compare/arekusandr-last-layer-vs-zenguard-ai-fast-llm-security-guardrails.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, last_layer or fast-llm-security-guardrails? last_layer: Dormant. fast-llm-security-guardrails: Slowing. Compare maintenance labels, days since push, and release cadence in the trust section below - stars alone do not measure maintenance. ### Where are the full trust reports for last_layer and fast-llm-security-guardrails? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [last_layer trust report](/tools/arekusandr-last-layer/trust); [fast-llm-security-guardrails trust report](/tools/zenguard-ai-fast-llm-security-guardrails/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=arekusandr-last-layer`](/api/graphcanon/graph?tool=arekusandr-last-layer) - LLM index: [/llms.txt](/llms.txt) - Full corpus: [/llms-full.txt](/llms-full.txt) _GraphCanon - The knowledge graph for AI development. https://www.graphcanon.com/_