head to head · open source
SkillSpector vs arcjet-js
SkillSpector has 23,981 GitHub stars, 2,070 forks, 136 open issues and last shipped yesterday. arcjet-js has 698 stars, 35 forks, 11 open issues and last shipped 5 days ago. SkillSpector leads on adoption by 3,336% (23,981 vs 698 stars). SkillSpector is written in Python under Apache-2.0; arcjet-js is written in TypeScript under Apache-2.0. SkillSpector has attracted 9% as many forks as stars, arcjet-js 5%. SkillSpector was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 3 topic tags (agent-security, ai-security, mcp), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| SkillSpector | arcjet-js | |
|---|---|---|
| GitHub stars | ★ 24K | ★ 698 |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Python | TypeScript |
| Last push | 2026-11-02 | 2026-10-29 |
| Forks | ⑂ 2.1K | ⑂ 35 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick SkillSpector if
- You weight community size — 24K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick arcjet-js if
- You want the arcjet-js feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and arcjet-js fits your workflow better
About SkillSpector
SkillSpector Security scanner for AI agent skills. Detect vulnerabilities, malicious patterns, and security risks before installing agent skills. Overview AI agent skills (used by Claude Code, Codex CLI, Gemini CLI, etc.) execute with implicit trust and minimal vetting. In the 31,132 skill analyzed subset of the research dataset, 26.1% of skills contain vulnerabilities and 5.2% show likely malicious intent . SkillSpector helps you answer: "Is this skill safe to install?" SkillSpector is part of the NVIDIA Verified Skills pipeline, which scans, evaluates, and signs agent skills before publication. Skills that…
read the full SkillSpector overview →
About arcjet-js
Arcjet JS SDK [Arcjet][arcjet] is the runtime security platform that ships in your AI code. Detect prompt injection, authorize agent tool calls, redact sensitive data, and block bots and abuse. Real time security building blocks you call inside your app, before an action happens. This is the monorepo containing various [Arcjet][arcjet] open source packages for JS. Why Arcjet? Your app's AI features and agents take real actions, calling tools, reading data, hitting APIs. Arcjet runs inside that code and lets you enforce security on each action in real time, then audit what happened Which package do I need? Arcjet…
read the full arcjet-js overview →
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Frequently asked questions
Is SkillSpector or arcjet-js more popular?
SkillSpector has 23,981 GitHub stars and arcjet-js has 698. SkillSpector has the larger community by that measure.
Are SkillSpector and arcjet-js free?
Both are open source. SkillSpector is licensed under Apache-2.0 and arcjet-js under Apache-2.0. Neither carries a licence fee.
What is the difference between SkillSpector and arcjet-js?
SkillSpector is written in Python and arcjet-js in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, SkillSpector or arcjet-js?
Choose SkillSpector if you want the larger community (23,981 stars) or its Apache-2.0 licence terms. Choose arcjet-js if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.