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Cybersecurity · head to head

Arnica vs Nix

Arnica logo

Arnica

Cybersecurity

AI-native application security platform detecting and fixing vulnerabilities across the SDLC

From
Free
Free plan
Yes
Full reviewWebsite
Nix logo

Nix

Developer Tools

Purely functional package manager and the NixOS distribution built on it, for byte-reproducible environments

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Arnica per-identity pricing ($25-$50/person/year) requires tracking active developers; Nix the Nix language is lazy, dynamically typed and poorly documented, and its error messages frequently point at the wrong expression, so debugging a failing build is a skill that takes months rather than days to acquire.
  • They diverge on capability: Arnica covers AI SAST, Nix covers Content-addressed store.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Arnica and Nix actually diverge.

Attributes where Arnica and Nix differ
AttributeArnicaNix
Pricing modelPer-identity subscription with annual discountOpen source, no licence fee
PlatformsWeb, GitHub, IDELinux, macOS, Windows (via WSL)
CategoryCybersecurityDeveloper Tools

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Arnica

  • AI SAST
  • Software Composition Analysis
  • Secrets detection
  • IaC scanning
  • Container scanning
  • SBOM generation
  • Agentic rules
  • Pipelineless integration

Only in Nix

  • Content-addressed store
  • Declarative system configuration
  • Atomic upgrades and rollback
  • nix develop shells
  • Flakes
  • Nixpkgs
  • Binary caches
  • Home Manager

What people use each for

The jobs each tool is most often brought in to do.

Arnica

  • Detecting AI-generated vulnerabilities in Copilot and Cursor suggestionsnot Nix
  • Finding hardcoded secrets before they reach productionnot Nix
  • Mapping container vulnerabilities back to source codenot Nix
  • Generating SBOM for supply chain compliance requirementsnot Nix
  • Scanning infrastructure-as-code for misconfiguration risksnot Nix

Nix

  • A team that wants every developer and CI runner to use byte-identical toolchains without shipping a container for local worknot Arnica
  • Reproducing a research computation or a build years later from a pinned commit rather than a written recipenot Arnica
  • Managing a fleet of Linux servers declaratively with atomic rollback if a deployment breaks a servicenot Arnica
  • Building minimal container images from precise dependency closures instead of a base image plus a package managernot Arnica

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Arnica

  • Per-identity pricing ($25-$50/person/year) requires tracking active developers
  • Overage identity tracking via 90-day PR activity can be unpredictable
  • Free plan limited to weekly updates, requiring upgrade for real-time scanning
  • Advanced add-ons (Image Scanning, AI SAST, Agentic Rules Enforcer) pricing not published
  • On-premises deployment limited to Enterprise tier

Nix

  • The Nix language is lazy, dynamically typed and poorly documented, and its error messages frequently point at the wrong expression, so debugging a failing build is a skill that takes months rather than days to acquire.
  • Flakes are the way essentially everyone uses Nix in 2026 and are still formally an experimental feature behind a flag, meaning tutorials, official documentation and real practice disagree with each other constantly.
  • Anything that expects a conventional Linux filesystem layout breaks: prebuilt binaries, language package managers that download their own toolchains, and proprietary vendor installers all need patching or an FHS-compatible wrapper.
  • Project governance has been publicly fractious, producing the Lix fork and the separately funded Determinate Systems distribution, so a new adopter now has to choose which Nix before they can start.
  • The /nix/store grows without bound until you garbage collect, and on a developer laptop with several pinned nixpkgs revisions it routinely reaches tens of gigabytes.

Pricing, plan by plan

Arnica

Free
  • FreeFree
    • No credit card required
    • 14-day trial available
    • Weekly risk identification updates
  • Core Business$360/year
    • Monthly billing option at $30/identity/month
    • Annual billing at $25/identity/month (17% discount)
    • Real-time risk scanning and notifications
  • Core Enterprise$720/year
    • Monthly billing option at $60/identity/month
    • Annual billing at $50/identity/month (17% discount)
    • All Core Business features

Nix

Free
  • Nix and NixOSFree
    • LGPL-2.1 licensed, no commercial tier
    • Public binary cache at cache.nixos.org
    • Community support via forum, Matrix and GitHub

Which should you pick?

Choose Arnica if

  • You need ai sast.
  • You want to start without paying.
  • You work on Web, GitHub, IDE.
  • You also want software composition analysis.
Arnica review

Choose Nix if

  • You need content-addressed store.
  • You want to start without paying.
  • You work on Linux, macOS, Windows (via WSL).
  • You also want declarative system configuration.
Nix review

Questions people ask

Is Arnica or Nix better?
Neither clearly leads. Arnica starts at Free and Nix at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Arnica or Nix?
Arnica starts at Free and Nix at Free.
Does Arnica or Nix run on more platforms?
Arnica runs on Web, GitHub, IDE. Nix runs on Linux, macOS, Windows (via WSL).
Can I use Arnica for free?
Both have a free tier, so you can try either at no cost before committing.
What is Arnica best used for?
Arnica is most often used for detecting ai-generated vulnerabilities in copilot and cursor suggestions, finding hardcoded secrets before they reach production, mapping container vulnerabilities back to source code, generating sbom for supply chain compliance requirements. Of those, detecting ai-generated vulnerabilities in copilot and cursor suggestions and finding hardcoded secrets before they reach production are not what Nix is typically brought in for.
What can Arnica do that Nix cannot?
Arnica covers AI SAST, Software Composition Analysis, Secrets detection, IaC scanning. Nix covers Content-addressed store, Declarative system configuration, Atomic upgrades and rollback, nix develop shells.

Answered from the vendors’ own pages

Arnica: How are identities defined in Arnica pricing?

Identities are any users and other contributing entities that contributed code and/or had PR activity during the last 90 days. This ensures billing matches active developers.

Source
Nix: Do I have to run NixOS to use Nix?

No. The package manager runs fine on any Linux distribution and on macOS, and most teams start there with development shells rather than converting their servers.

Arnica: What is the annual discount?

Annual prepayment offers approximately 17% savings versus monthly billing. Core Business annual is $300/identity versus $360 for monthly.

Source
Nix: Is Nix a replacement for Docker?

It solves an adjacent problem. Nix reproduces the contents of an environment exactly; Docker distributes an image. Many teams use Nix to build the image.

Arnica: Can I cancel or downgrade Arnica anytime?

Yes. Subscriptions can be cancelled or downgraded at any time. Overage identities receive automatic protection with true-up invoicing.

Source
Nix: Are flakes safe to use in production?

They are used in production widely and are stable in practice, but they remain officially experimental, which means the interface can still change and documentation is split.

Nix: What is Lix and should I care?

Lix is a community fork of the Nix implementation created after governance disputes. It is largely compatible; the practical impact is that you must decide which implementation your team standardises on.

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