Comparison
ContribAI: Contribution assistant vs. audit-linked overnight PR desk.
ContribAI focuses on helping a developer ship a contribution across open-source repositories — the unit of work is a contributor’s pull request against an external repo. Driftlock focuses on the opposite shape: an internal team’s monorepo, where the unit of work is one overnight signal (CI failure, CVE, on-call alert) that becomes a signed pull request on the team’s own protected branches. The two products solve different problems; the comparison here is about posture, not feature parity.
Posture
Driftlock runs self-hosted in your VPC; no third-party LLM is ever called at the test step.
Identity
Commits sign with your cosign key in your KMS or HSM. Keys rotate on your schedule.
Audit
Seven per-PR columns — alert id, sandbox run hash, SBOM hash, approver chain, signature, diff bytes, triage verdict — replayable on your storage tier.
What they do
ContribAI in one paragraph.
ContribAI is a hosted contribution assistant that helps a developer draft and ship a pull request against an external open-source repository; the unit of work is a contributor’s contribution flowing outward from the developer to the upstream repo.
Where Driftlock differs
Eight dimensions where the posture diverges.
Each row names one axis — autonomy, hosting, audit, signing, SBOM, sandbox, monorepo scale, CI touch — and states both sides on that axis. No feature checklist, no marketing re-framing.
Axis · autonomy scope
Them
Helps a developer draft and refine a contribution; the human is in the loop on every commit.
Driftlock
Acts only on overnight signals already in your stack (CI failure, Dependabot alert, CVE, on-call page); no contribution draft, no run.
Axis · self-hosting
Them
Hosted assistant; the customer does not run the model or the contribution tooling inside their own cloud.
Driftlock
Single Helm + Terraform deployment inside your VPC, with no third-party LLM calls at any step.
Axis · audit trail
Them
Records contribution history on the ContribAI control plane; replay requires ContribAI as the intermediary.
Driftlock
Records seven per-PR columns (alert id, sandbox run hash, SBOM hash, approver chain, signature, diff bytes, triage verdict) replayable on your storage tier.
Axis · commit-signing
Them
Signs contributions with the contributor’s identity; key handling follows the contributor’s Git host, not the customer’s KMS.
Driftlock
Commits sign with your cosign key kept in your KMS or HSM; key rotation happens on your schedule.
Axis · SBOM
Them
Does not emit a per-contribution SBOM; SBOM concerns belong to the upstream repo’s release pipeline.
Driftlock
Emits an SBOM hash per PR, recorded alongside the diff and the signature so reviewers can diff two SBOMs without re-running the build.
Axis · sandbox execution
Them
Operates against the contributor’s local checkout; the customer does not pin the toolchain inside a managed sandbox.
Driftlock
Runs inside a hermetic sandbox that mounts the existing monorepo’s toolchain and test cache, and replays the original regression before opening the PR.
Axis · monorepo scale
Them
Designed for many small repositories and many contributors; large monorepos are not the design target.
Driftlock
Built for one large monorepo per deployment; the sandbox mounts the monorepo’s existing caches so a CI rerun is bounded by what CI itself already proves.
Axis · CI touch
Them
Does not read CI failures as the primary trigger surface; CI is a downstream check on a contribution.
Driftlock
Treats CI as the source of truth — the agent reads CI failures as triggers and reruns the original regression inside the sandbox before opening the PR.
8 axes · posture-level · no feature checklist
FAQ
Questions comparison-stage buyers ask.
See it on your stack
Compare on a real monorepo, not a slide deck.
The architecture page names the four signal sources the watcher reads; the governance page enumerates the seven per-PR columns a regulator replays. Run the comparison against one of your real monorepos on a ten-day scoped trial — you'll see the diffs Driftlock ships and the audit trail your reviewers sign.