Chainloop Signs Every Artifact Your CI Pipeline Builds

Turning CI Output Into Signed, Queryable Evidence

Chainloop is an open-source evidence store and policy engine for software supply chain security, and Help Net Security highlighted it on August 10, 2026. The premise is that continuous integration pipelines already generate the artifacts auditors and security teams want — bills of materials, scan results, test reports — and the problem is not producing them but collecting, signing, and proving they exist.

• Runs inside GitHub Actions, GitLab, Jenkins, or Dagger as a command line tool
• 17-plus evidence formats handled natively, including CycloneDX, SPDX, OpenVEX, SARIF, and the four CSAF document types
• Rego policies from Open Policy Agent evaluated automatically and recorded in the attestation
• Signing via Sigstore or organizational PKI, including AWS KMS and Keyfactor

The flow is simple in outline. The tool runs at the end of a build, picks up what the pipeline produced, uploads those files to content-addressable storage, and references each one inside a signed in-toto attestation. What was previously a pile of build outputs scattered across CI job logs becomes a single signed record.

What Problem Does an Evidence Store Actually Solve?

Most organizations that generate SBOMs are already generating them. The failure mode is downstream: nobody can find the SBOM for a specific release six months later, nobody can prove it was produced by the pipeline that claims to have produced it, and nobody checked whether it met policy at the time.

Chainloop's Workflow Contracts address the second and third of those. A contract defines what a build is required to deliver — which evidence types, in which formats — and Rego policies attached to that contract are evaluated automatically, with the results written into the attestation before it is signed. A build that fails to produce required evidence is visibly non-compliant rather than quietly incomplete.

That is the meaningful shift. Instead of security teams chasing developers for artifacts after the fact, the requirement lives in the pipeline definition and the record is generated as a side effect of building.

Why Does Format Coverage Matter Here?

Seventeen named formats with first-class handling is a practical detail that separates a usable tool from a proof of concept. CycloneDX and SPDX for bills of materials, OpenVEX for exploitability statements, SARIF for static analysis, ZAP results for dynamic testing, BlackDuck output for composition analysis, PrismaCloud Twistcli for container scans, GitLab security reports, JUnit for tests, JaCoCo for coverage, plus Helm charts and container image references.

A real pipeline produces several of those simultaneously, from tools chosen years apart by different teams. An evidence store that only understands two formats forces normalization work before it delivers value. One that understands seventeen fits the pipeline that already exists.

Where It Fits Alongside Existing Defenses

Supply chain attestation is the layer beneath the pipeline-hardening practices we covered in our guide to securing AI coding agents in CI and in hardening MCP agent pipelines against supply chain attacks. Those focus on controlling what runs inside the build. Chainloop focuses on proving what came out of it.

Both matter, and they compose. Signed evidence of a compromised build is still evidence of a compromised build — but it is evidence you can query, correlate, and act on, which is exactly what incident responders lack when a dependency turns out to be malicious. It also fits the measurement mindset behind OWASP's Subtractive Security project, which scores the attack paths a control actually removes.

Deployment and Availability

Chainloop is free and open source on GitHub. Teams can use a hosted instance or self-host the control plane on Kubernetes via the provided Helm chart. Artifacts can route onward to OCI registries, cloud storage, or downstream tools such as Dependency-Track.

For organizations facing supply chain attestation requirements, an open-source option that plugs into existing CI without replacing it is a low-friction starting point. More defensive tooling in our AI security coverage.

Sources: Help Net Security — August 10, 2026; Chainloop on GitHub — August 2026.