# Sonatype Repository Firewall alternatives, compared > When Sonatype Repository Firewall fits, why teams look elsewhere, which alternatives block packages at install time, and how Chainsaw differs from it. Source: https://chain305.com/sonatype-repository-firewall-alternative/ --- # Sonatype Repository Firewall alternatives Repository Firewall quarantines at the proxy. The alternatives differ in what they need around them. When Sonatype Repository Firewall is the right choice, why teams look elsewhere, and how the alternatives compare. By [Muhammad Zeeshan Sultan](https://chain305.com/about/#founder), founder of Chain305 · October 2026 Questions and answers Sonatype Repository Firewall is a policy gate on proxy repositories in Nexus Repository 3 Pro or self-hosted Artifactory. The main alternatives are Chainsaw, JFrog Curation, Socket and CLI wrappers such as Aikido Safe Chain. Chainsaw is a registry proxy for 16 ecosystems with no repository manager required: a team first changes one registry URL per package manager. Chainsaw runs as SaaS or inside your own network, and the decision engine is open source under Apache-2.0. ## What does Sonatype Repository Firewall do? Sonatype Repository Firewall is a policy gate on proxy repositories: Repository Firewall checks each new open-source component requested through a proxy repository against your policies and quarantines components that fail, before those components reach the repository and the developer. Policies live in Sonatype’s IQ Server, and Repository Firewall runs with [Nexus Repository 3 Pro, self-hosted or cloud, or with self-hosted JFrog Artifactory](https://help.sonatype.com/en/repository-firewall.html) through [the Firewall for Artifactory plugin](https://www.sonatype.com/products/integrations/jfrog-artifactory). Sonatype’s docs list 18 formats, including npm, PyPI, Maven, Go modules, Docker and Hugging Face. Three features do most of the supply-chain work: - **[Release Integrity](https://help.sonatype.com/en/release-integrity.html)** uses AI and machine-learning tools to rate each new release. A release with unusual behaviour is rated Suspicious, stays in quarantine and goes to the Sonatype Research team for review. A malicious release stays quarantined; a release that passes review is rated Normal and, with automatic quarantine release on, is released without manual work. - **[Namespace Confusion Protection](https://help.sonatype.com/en/namespace-confusion-protection.html)** builds a list of your internal namespaces from your hosted repositories and quarantines public components that use those namespaces, for example a public npm package published under your internal scope. Namespace Confusion Protection covers every supported format except Docker and Hugging Face. - **[Quarantine and waivers](https://help.sonatype.com/en/firewall-quarantine.html).** A quarantined component cannot be downloaded through the proxy; most clients see an HTTP 403. A reviewer releases a component by adding a waiver, or the component is released automatically once its failing violations close. Only newly requested components are quarantined. Components already in the proxy are audited. ## When is Sonatype Repository Firewall the right choice? Sonatype Repository Firewall is the right choice when the blocking should live inside a repository manager you already run, in any of four situations: - You already run Nexus Repository Pro, or self-hosted Artifactory, and want blocking inside the repository you have. - Your teams already run Sonatype’s IQ Server and want to manage blocking policies there. - You want a vendor research team to review suspicious new releases before they are released to your builds. - Your procurement team prefers extending an existing Sonatype contract over onboarding a new vendor. If that describes you, Repository Firewall is a reasonable choice, and the comparison below may not change your mind. Chainsaw can still run in monitor mode first, next to Repository Firewall, to compare decisions. ## Why look for an alternative? Teams usually look for a Sonatype Repository Firewall alternative for one of three reasons: 1. **No Nexus Repository Pro or self-hosted Artifactory.** Sonatype’s Artifactory setup guide says [Artifactory SaaS is not supported](https://help.sonatype.com/en/jfrog-artifactory-setup.html), and a team with no repository manager would have to adopt one first. 2. **The team wants to read the code that makes the block decision** before routing the organisation’s installs through Repository Firewall. 3. **The block must hold on laptops, CI and the network**, not only for installs that happen to use the repository URL. Each reason is about what surrounds the firewall, since Repository Firewall and Chainsaw both stop a failing package at the proxy. ## What are the alternatives to Sonatype Repository Firewall? The main alternatives to Sonatype Repository Firewall are Chainsaw, JFrog Curation, Socket and CLI wrappers, for example Aikido Safe Chain and Datadog’s Supply-Chain Firewall. The alternatives differ mostly in where the check sits. Chainsaw is a registry proxy in front of any registry, or the registry itself, with an open-source decision engine and SaaS, VPC, self-hosted or air-gapped deployment from one binary. JFrog Curation is a policy gate in Artifactory and the natural choice for JFrog shops. Socket works through its own tooling and integrations, with deep behavioural analysis on npm. A CLI wrapper is free and quick to try on one developer’s machine, but a CLI wrapper is not an organisation-wide control. Alternative Where it sits Notes **Chainsaw** A registry proxy in front of any registry, or as the registry Open-source decision engine; SaaS, VPC, self-hosted or air-gapped from one binary **[JFrog Curation](https://docs.jfrog.com/security/docs/on-demand-curation)** A policy gate in Artifactory The natural choice for JFrog shops. [JFrog Curation alternatives](https://chain305.com/jfrog-curation-alternative/) **Socket** Its own tooling and integrations Deep behavioural analysis on npm; SaaS-first. [Socket vs Chainsaw](https://chain305.com/vs-socket/) **CLI wrappers** ([Aikido Safe Chain](https://github.com/AikidoSec/safe-chain), [Datadog’s Supply-Chain Firewall](https://github.com/DataDog/supply-chain-firewall)) On one developer’s machine Free and quick to try; not an organisation-wide control ## How is Chainsaw different from Sonatype Repository Firewall? ### Do you need a repository manager? **Sonatype Repository Firewall:** Yes. Sonatype Repository Firewall runs with Nexus Repository 3 Pro, or with self-hosted Artifactory through the Firewall for Artifactory plugin and a licence. Sonatype’s Artifactory setup guide says [Artifactory SaaS is not supported](https://help.sonatype.com/en/jfrog-artifactory-setup.html). **Chainsaw:** No. Chainsaw is a registry proxy that package managers and CI pull through, so Chainsaw proxies the public registries directly, after a one-line registry URL change per package manager. A PyPI team first changes the index URL in `pip.conf` and keeps the rest of the build as it is. Chainsaw covers 16 ecosystems, including npm, PyPI, Maven, Go, Cargo and Docker. On npm and PyPI the same URL also serves packages you publish to Chainsaw, when no public package has that name; other formats use a separate hosted repository. If you keep Nexus or Artifactory, Chainsaw can sit in front of the repository manager, or Chainsaw can be the registry itself. [How that coexistence works.](https://chain305.com/vs-artifact-managers/) ### Can you read the decision logic? **Sonatype Repository Firewall:** Sonatype Repository Firewall is a licensed product, with policy evaluated by IQ Server. Check with Sonatype for what you can inspect. **Chainsaw:** The CLI and the decision engine are open source under Apache-2.0 at [github.com/chain305/chainsaw-core](https://github.com/chain305/chainsaw-core). A security team can read the function which returns a refusal before routing any installs through Chainsaw, and can run the same engine locally as a CLI with no account. The hosted product, with the dashboard, policy, SSO/SCIM and audit, is not open source. ### How are brand-new releases handled? **Sonatype Repository Firewall:** [Release Integrity](https://help.sonatype.com/en/release-integrity.html) rates each new release. A Pending or Suspicious rating fails the Integrity-Rating policy at the proxy, so the release stays quarantined until Sonatype’s review clears it. **Chainsaw:** By time and by code. New npm and PyPI versions are held for 48 hours by default, so version ranges resolve to the newest older version instead of failing the build; the hold is a setting, `release_min_age_hours`. A default rule refuses packages first published less than a day ago. Install-script and import-time checks run on the first download, so some malicious releases are refused before any feed lists them. ### How is dependency confusion stopped? **Sonatype Repository Firewall:** [Namespace Confusion Protection](https://help.sonatype.com/en/namespace-confusion-protection.html) is the Repository Firewall feature for dependency confusion. Namespace Confusion Protection reads your internal namespaces from repositories marked as proprietary and refreshes the list every two hours by default. Sonatype advises moving open-source components out of those repositories before you turn it on. **Chainsaw:** Chainsaw stops dependency confusion with reserved namespaces, a setting on the one proxy URL that every package manager in the organisation pulls through. You declare patterns, for example `@acme/*` on npm, `com.acme.*` on Maven or `acme.` on PyPI, and the Chainsaw proxy refuses any package from a public registry whose name matches. The check is evaluated on every ecosystem, but only for the patterns you declare. A recommended starter pack ships, and the proxy warns at startup when none is applied. Chainsaw does not apply a starter pack by default, because Chainsaw cannot know your internal names. The first public package that copies a reserved name is refused at the fetch, with no per-package allow-listing. ### What stops installs going around it? **Sonatype Repository Firewall:** Check with Sonatype how a developer’s direct registry URL is detected and closed. **Chainsaw:** Chainsaw closes the bypass with three controls. First, a CI gate fails builds pulled from elsewhere. Second, MDM settings pin laptops to the proxy URL. Third, egress rules block direct registry traffic, and Chainsaw reports an attestation of whether the gap is closed. A one-line `.npmrc` edit pointing npm straight at the public registry is the bypass the three controls are built to catch. ### How does a rollout start? **Sonatype Repository Firewall:** Repository Firewall is [configured per proxy repository](https://help.sonatype.com/en/firewall-audit-and-quarantine-capability.html), with audit and quarantine; the steps depend on your Nexus version. **Chainsaw:** A Chainsaw rollout is a gradual switch. Five seeded rules refuse from day one: CISA KEV entries, packages first published less than 1 day ago, install scripts fetching remote URLs, import-time execution and bidi Unicode. Every other rule runs in monitor mode first, showing what the rule would refuse on your own dependencies, then enforces one rule at a time. ### What does it look at beyond CVEs? **Chainsaw:** Chainsaw’s check beyond CVEs is a set of 25 supply-chain detection signals, plus a default 48-hour release hold. Chainsaw runs up to all 25 on npm and PyPI (2 opt-in), 22 on RubyGems, and at least 4 on every proxied ecosystem. The signals include install-script exfiltration, maintainer-account takeover, version anomalies, hidden Unicode, publish-velocity worm bursts and more. Five seeded rules block from day one: CISA KEV, packages under 1 day old, install scripts fetching remote URLs, import-time execution and bidi Unicode. Install-script and import-time checks run on the first download: a new release whose install script fetches a remote URL is refused before any feed lists the package as malicious. [The full list.](https://chain305.com/product/policy/) ## How do you test an alternative without risk? The low-risk test is to run Chainsaw in monitor mode next to Sonatype Repository Firewall for a week. In monitor mode Chainsaw records what each rule would have refused without refusing anything, so installs keep working and Repository Firewall keeps quarantining as before. After a week, compare Chainsaw’s decisions with Repository Firewall’s quarantines on your own dependencies, then move one Chainsaw rule at a time to enforce. Chainsaw can sit in front of Nexus Repository or Artifactory for the test, so both see the same installs. The free Chainsaw CLI runs locally with no account, and hosted Chainsaw is free for 3 people, so the test needs no purchase. About this comparison Chain305, the company that makes Chainsaw, wrote this comparison. Every claim about another product was checked against that vendor's public documentation. Last checked: 2 November 2026. If anything here is wrong or out of date, email [sales@chain305.com](mailto:sales@chain305.com) and it will be corrected. How these pages are written and checked: [editorial policy](https://chain305.com/editorial-policy/). Compare on your own dependencies ## Run Chainsaw in monitor mode next to Repository Firewall Start a free org in monitor mode and compare what each would have refused this week. [Start in monitor mode](https://chain305.com/chainsaw/signup) [Chainsaw with Nexus or Artifactory →](https://chain305.com/vs-artifact-managers/)