# SkillSpector review

> SkillSpector is NVIDIA's security scanner that checks AI agent skills for vulnerabilities, malicious patterns, and supply-chain risks before you install them.

Devtoolwatch Board, the week of Oct 25–31, 2026. Canonical page: https://index.devtoolwatch.com/tools/nvidia-skillspector/

## TL;DR

SkillSpector is a Python command-line scanner that checks Claude Code, Codex, and MCP agent skills for risks such as prompt injection and data exfiltration. It is for developers who want to vet skills before installing them. It runs fast static checks by default, adds optional LLM semantic analysis, and is part of NVIDIA's Verified Skills pipeline.

## SkillSpector at a glance

- **Category:** [Evals and observability](https://index.devtoolwatch.com/categories/evals-and-observability/)
- **Maintained by:** NVIDIA Corporation (organization, [@NVIDIA](https://github.com/NVIDIA) on GitHub)
- **License:** Apache 2.0
- **Language:** Python, TypeScript, JavaScript
- **Repository:** [github.com/NVIDIA/SkillSpector](https://github.com/NVIDIA/SkillSpector)
- **Website:** [docs.nvidia.com/skills/scanning-agent-skills](https://docs.nvidia.com/skills/scanning-agent-skills)
- **Latest release:** [v2.13.2](https://github.com/NVIDIA/SkillSpector/releases/tag/v2.13.2) on GitHub, Oct 28, 2026
- **First published:** Mar 21, 2026

## What SkillSpector does

- SkillSpector scans Git repositories, URLs, zip files, directories, or single SKILL.md files.
- SkillSpector checks vulnerability patterns across 17 categories, including prompt injection, data exfiltration, privilege escalation, memory poisoning, and MCP tool poisoning.
- SkillSpector queries OSV.dev for known vulnerable dependencies and falls back to offline data when network access is unavailable.
- SkillSpector gives each scan a 0-100 risk score with severity labels and recommendations.
- SkillSpector writes reports as terminal output, JSON, Markdown, or SARIF for CI and IDE tooling.
- SkillSpector supports baseline files that suppress accepted findings, so re-scans report and score only new issues.
- SkillSpector can scan and compare MCP Registry snapshots, listing added, removed, and changed servers.

### How it works

SkillSpector runs as a CLI command, `skillspector scan`, either installed with uv or pip or inside a locally built Docker image. Static analysis runs by default. For semantic analysis, you set SKILLSPECTOR_PROVIDER and an API key for an OpenAI-compatible endpoint, Anthropic, or a local server such as Ollama, vLLM, or llama.cpp. The LLM then compares what a skill claims with what its code appears to do.

## How to install SkillSpector

**With uv (CLI only)**

```
uv tool install git+https://github.com/NVIDIA/skillspector.git
```

**With uv, including the MCP extra**

```
uv tool install 'skillspector[mcp] @ git+https://github.com/NVIDIA/skillspector.git'
```

**Build the Docker image**

```
docker build -t skillspector .
```

### Requirements

- Python in a virtual environment, created with uv or pip, unless you use the Docker image.
- Docker, if you want to run SkillSpector without installing Python. The image is based on Python 3.12-slim-bookworm.
- An LLM provider and API key, needed only for optional semantic analysis.

### First steps

1. Scan a local skill directory with `skillspector scan ./my-skill/`.
2. Write a machine-readable report with `skillspector scan ./my-skill/ --format json --output report.json`.
3. For semantic checks, set SKILLSPECTOR_PROVIDER and the matching API key, such as OPENAI_API_KEY, before scanning.
4. Accept known findings with `skillspector baseline ./my-skill/ -o .skillspector-baseline.yaml`, then scan with `--baseline`.

## Who SkillSpector is for

- Developers vetting third-party Claude Code, Codex, or MCP skills before installing them.
- Teams gating skill installs in CI with SARIF output and fail-on-incomplete checks.
- Skill authors preparing skills for publication through NVIDIA's evaluation pipeline.
- Teams tracking changes between MCP Registry snapshots.

### Limitations

- SkillSpector caps remote and archive inputs at 100 MiB and 10,000 zip entries. Analyzers read at most 1 MB per file.
- SkillSpector's recursive scans default to 32 skills. Time and size budgets can still leave coverage incomplete.
- SkillSpector disabled the Codex CLI analysis provider because its read-only sandbox permits access to host secrets.
- SkillSpector's contributed batch scanner defaults to DeepSeek and was not tested against local models.

## Usage data (the week of Oct 25–31, 2026)

- Board rank: #13 overall, #1 in Evals and observability, momentum score 94
- New GitHub stars per week (last 12 weeks): Aug 9: 288; Aug 16: 225; Aug 23: 345; Aug 30: 1.1k; Sep 6: 741; Sep 13: 813; Sep 20: 543; Sep 27: 919; Oct 4: 617; Oct 11: 566; Oct 18: 976; Oct 25: 2.4k

## SkillSpector alternatives

| Rank | Tool | Stars | Downloads/wk |
|---|---|---|---|
| #2 | [Judgeval](https://index.devtoolwatch.com/tools/judgmentlabs-judgeval/) | 1.1k | 80.2k |
| #3 | [A.I.G (AI-Infra-Guard)](https://index.devtoolwatch.com/tools/tencent-ai-infra-guard/) | 7.2k | – |
| #4 | [Langfuse](https://index.devtoolwatch.com/tools/langfuse/) | 36.8k | 9.8M |
| #5 | [Opik](https://index.devtoolwatch.com/tools/opik/) | 23.1k | 709.1k |
| #6 | [promptfoo](https://index.devtoolwatch.com/tools/promptfoo/) | 26.7k | 1.2M |
| #7 | [garak](https://index.devtoolwatch.com/tools/garak/) | 9.8k | 12.9k |

## SkillSpector FAQ

### Is SkillSpector free and open source?

Yes. SkillSpector's source code is on GitHub (NVIDIA/SkillSpector) under the Apache 2.0 license, so you can use it for free.

### How do I install SkillSpector?

Run `uv tool install git+https://github.com/NVIDIA/skillspector.git`. The install section above has the other options from the project's README.

### Is SkillSpector still maintained?

Yes. The NVIDIA/SkillSpector repository was last updated on Oct 31, 2026, and the latest release, v2.13.2 on GitHub, came out on Oct 28, 2026.

### How popular is SkillSpector?

SkillSpector has 23.7k GitHub stars as of Nov 1, 2026. It gained 2.4k new stars in the week of Oct 25–31, 2026, against a 12-week average of 791 a week. That made it #1 among LLM evals and observability tools on the Devtoolwatch Board.

### What are the best alternatives to SkillSpector?

Other LLM evals and observability tools on the Devtoolwatch Board in the week of Oct 25–31, 2026, by momentum: Judgeval (#2), A.I.G (AI-Infra-Guard) (#3), Langfuse (#4), Opik (#5), promptfoo (#6). The alternatives table above has their numbers.

### Is SkillSpector legit?

SkillSpector is published by NVIDIA in the NVIDIA GitHub organization. It is part of the NVIDIA Verified Skills pipeline, which scans, evaluates, and signs agent skills before they are published to the NVIDIA skills catalog. It also serves as the security tier inside SkillEvaluator.

### Does SkillSpector need an LLM?

SkillSpector does not need an LLM. It runs fast, deterministic static checks by default, and `--no-llm` keeps scans static. Optional LLM semantic analysis compares what a skill claims with what its code appears to do. This helps catch description-behavior mismatches and vague triggers.

### Can SkillSpector run in CI?

SkillSpector can run in CI. It writes SARIF reports for CI and code scanning systems, and JSON reports for automation. The `--fail-on-incomplete` flag fails a build when scan coverage is incomplete.

### How do I handle false positives in SkillSpector?

SkillSpector supports baselines. Create one with `skillspector baseline`, then scan with `--baseline` so that only new findings are reported and scored. Baselines can use glob rules or exact fingerprints. Fingerprints stay active again when the source or the SkillSpector version changes.

### Which LLM providers does SkillSpector support?

SkillSpector works with OpenAI-compatible endpoints, Anthropic, and local OpenAI-compatible servers such as Ollama, vLLM, and llama.cpp. You select one with SKILLSPECTOR_PROVIDER. The Codex CLI provider is disabled.

## Sources

1. [NVIDIA/SkillSpector on GitHub](https://github.com/NVIDIA/SkillSpector)
2. [SkillSpector README](https://github.com/NVIDIA/SkillSpector/blob/main/README.md)
3. [SkillSpector website](https://docs.nvidia.com/skills/scanning-agent-skills)
4. [Release v2.13.2 (Oct 28, 2026)](https://github.com/NVIDIA/SkillSpector/releases/tag/v2.13.2)
5. [Release v2.13.1 (Oct 23, 2026)](https://github.com/NVIDIA/SkillSpector/releases/tag/v2.13.1)
6. [Release v2.13.0 (Oct 16, 2026)](https://github.com/NVIDIA/SkillSpector/releases/tag/v2.13.0)
7. [Hacker News: CUDA 11.0](https://news.ycombinator.com/item?id=23772245)
8. [Hacker News: CUDA Toolkit Release Notes](https://news.ycombinator.com/item?id=21618774)
9. [Hacker News: SkillSpector](https://news.ycombinator.com/item?id=48509844)
10. [Devtoolwatch Board, the week of Oct 25–31, 2026](https://index.devtoolwatch.com/)