NVIDIA NeMo Guardrails vs Prompt Inspector
NVIDIA NeMo Guardrails
developer.nvidia.comPrompt Inspector
promptinspector.ioSide by side
| Figure | NVIDIA NeMo Guardrails | Prompt Inspector |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | Yes | Yes |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 3 | 5 |
| Spec score · LLM Security Tools | 8.6 (#4) | 8.5 (#5) |
| Documentation depth | The documentation covers installation, configuration, Colang, APIs, evaluation, vulnerability scanning, observability, Docker, microservices, troubleshooting and security. | The documentation site covers architecture, REST use, Python and Node SDKs, MCP setup and open-source deployment. |
| Integrations | The documentation lists integrations with NVIDIA safety models, community models, third-party APIs, Python actions, and LangChain tools. | The maker lists a REST API, Python SDK, Node.js SDK, MCP server, and agent skills for OpenClaw and Claude Code. |
| License | The NeMo Guardrails library is licensed under the Apache License 2.0. | The core repository and documentation identify the open-source edition as AGPL-3.0 licensed. |
| Purpose | NeMo Guardrails is an open-source Python package for adding programmable guardrails to LLM-based applications. | Prompt Inspector provides real-time prompt injection detection, sensitive word filtering, and AI safety guardrails through an API call. |
| Python SDK | Applications can use the LLMRails and RailsConfig Python APIs, including synchronous and asynchronous generation methods. | The official Python package is installed with pip and exposes a PromptInspector client with detect and close methods. |
| Repository activity | The public GitHub repository shows about 7.0k stars and 812 forks. | The main public repository shows seven commits, two stars and no forks on the opened page. |
| What it does | NeMo Guardrails is an open-source Python package that intercepts LLM inputs and outputs and applies programmable policies to block, modify or validate content. | Prompt Inspector places a real-time security layer between untrusted input and an LLM application or agent. |
Plans
NVIDIA NeMo Guardrails
- Open-source NeMo Guardrails libraryFree
- Open-source NeMo Guardrails libraryFree
- NeMo Guardrails microservicePriced on request
Prompt Inspector
- FreeFree
- FreeFree
- EnterprisePriced on request
- ProPriced on request
- StarterPriced on request
In their own words
NVIDIA NeMo Guardrails
NVIDIA NeMo Guardrails is an open-source Python package for adding programmable policy and safety checks to applications built with large language models. It can block, alter, or validate inputs and model responses that are unsafe, off-topic, malicious, or against configured policies. Its rails cover input, retrieval, dialog, execution, and output stages. Developers can configure behavior with YAML files, Colang flows, built-in guardrails, and custom actions. The catalog includes content safety, jailbreak protection, topic control, PII detection, agentic security, tool calling, hallucination and fact-checking, and model self-checks. Applications can use the Python SDK or a Guardrails server with HTTP endpoints such as OpenAI-style chat completions. The library supports Windows, Linux, and macOS, and can run in a self-managed Python environment. The installation guide lists Python 3.10 through 3.13 and at least one CPU with 4GB RAM; external models may require separately deployed GPUs. The open-source library costs nothing, though external models and services may need separate setup. NVIDIA cautions that no single rail covers every adversarial prompt and advises defense in depth and evaluation.
Prompt Inspector
Prompt Inspector has no write-up on Specifiction yet; its figures are above.