By Jason Meridth and Vinaya Damle

We are excited to announce that Privateer has officially been approved as an OpenSSF Sandbox project under the ORBIT Working Group (Open Resources for Baselines, Interoperability, and Tooling). Privateer is a plugin-based framework designed to deliver automated security and compliance evaluation across software source code, repository configurations, and deployed systems.

The Challenge: Turning Security Requirements into Reviewable Findings

Modern cybersecurity frameworks, such as the OSPS Baseline and regulation like the European Union Cyber Resilience Act (CRA), require software maintainers and organizations to demonstrate rigorous security practices. However, traditional deterministic security scanners often struggle when evaluating qualitative, “fuzzy,” or human-written evidence, such as security policies, governance documentation, or complex repository setup files.

Maintainers often get three options: slow manual reviews, rigid tools that break on unstructured documents, or an AI’s unverified opinion. Privateer uses each where it fits. Deterministic checks run first and settle what they can. An optional large language model (LLM) step reviews evidence those checks can’t parse, like a security policy or governance doc. Anything still uncertain gets marked Needs Review, so a human makes the final call.

What is Privateer?

Privateer is a plugin-based evaluation harness that lets you write evaluators quickly. While policy enforcement engines like AMPEL act as gatekeepers to block non-compliant builds, Privateer focuses on evaluating evidence and providing structured assessments and opinions on whether specific security controls pass, fail, or need human review.

Privateer evaluates against control catalogs maintained separately, as part of the Gemara ecosystem. In Gemara, one group defines the Governance, Risk, and Compliance (GRC) requirements and another measures them.

Using Privateer with OSPS Baseline

After installing the Privateer Command Line Interface, pvtr, running the baseline scanner is just a matter of writing your configuration file with one or more targets and then running a single command.

Here’s an example of scanning the Gemara source repository against OSPS Baseline using the OpenSSF GitHub Repo plugin:

# config.yml
targets:
  gemara:
    plugin: github-repo
    policy:
      catalogs:
        - osps-baseline
      applicability:
        - maturity-1
    vars:
      owner: gemaraproj
      repo: gemara
      token: <github token>

$ pvtr run --auto-install

To run the same scan in CI, add the OSPS Baseline GitHub Action to a scheduled workflow. It can upload failed controls to GitHub code scanning as SARIF. To publish signed results to GRC Store, call the pvtr-publish-results reusable workflow instead.

Key capabilities of Privateer include:

Plugin-Based Evaluation Architecture: Privateer uses modular plugins to evaluate repositories, configurations, infrastructure, and deployed systems against independently maintained security control catalogs.
AI-Assisted Evidence Review: With optional LLM integration, Privateer plugins can review selected human-written evidence when deterministic checks cannot reach a conclusion. AI is not required, and uncertain cases remain Needs Review. These findings can support CRA readiness and other assurance workflows, but they do not independently determine legal compliance.
Interoperable GRC Integration: Privateer uses Gemara schemas to produce machine-readable evaluation logs that can serve as inputs to compliance dashboards, audit workflows, attestations, and other GRC tooling. For example, the OpenSSF GitHub Repo plugin reads a project’s Security Insights file, so a security contact, contributing guide, or vulnerability policy declared there can be evaluated without anyone reading prose.
Community Governance & Neutrality: Originally developed with engineering contributions from Sonatype, Revanite, and Microsoft, Privateer is transitioning to neutral governance as an OpenSSF Sandbox project sponsored by the ORBIT Working Group. This creates an open, transparent home for collaboration across the OpenSSF ecosystem.
Public Registry for Controls & Evaluators: While plugin authors may optionally embed their controls into the codebase, they can also harness GRC Store to import control definitions that are independently maintained by other publishers. Privateer plugin authors may also publish their plugin to GRC Store to enable one-line installations, and users can easily publish immutable evaluation logs with verifiable provenance using specialized tools from the Gemara ecosystem.

Get Involved

Visit the Project Website
Explore the Code: Visit the Privateer repository and the pvtr-github-repo-scanner plugin on GitHub.
Join the Conversation: Connect with maintainers in the #wg-orbit channel on the OpenSSF Slack, connect with the community in the #privateer channel on the OpenSSF Slack, and follow us on LinkedIn.
Attend Working Group Meetings: Participate in the Privateer project calls, held every two weeks, to help shape the future of open source GRC engineering.

About the Authors

Jason Meridth, Revanite. I’m a Staff+ Software Engineer with over three decades of experience building software systems, from cloud-native infrastructure to distributed systems. I maintain several open source projects, including major CNCF and OpenSSF projects, with a focus on reliability, security, and developer experience.

Vinaya Damle, Microsoft. My work includes exploring how open source tools can support software supply-chain security and Cyber Resilience Act readiness. I’m interested in working with the community to make dependency assessment and security evaluation more practical for software manufacturers.