Registry compatibility

An OCI registry is suitable for Rootform Dialect and Policy Pack artifacts only when it preserves the rootform-oci-core-v1 profile. Generic OCI support is not a Rootform qualification. A qualification applies to the tested registry and authentication path, not to every deployment or feature of that product.

Qualified registry paths

Registry	Pull and authentication	Publication and identity	Boundary
GitHub Container Registry (GHCR)	Public package accessed with a Docker credential helper	Custom media types, publish, exact repull by digest, locked recovery, and vendor repair	The qualification does not separately assert the Bearer challenge exchange, anonymous pull, or private-package access.
CNCF Distribution 3.0	Anonymous repository over TLS with a test CA	Custom media types, publish, exact repull by digest, locked recovery, and vendor repair	Private Basic authentication and other Distribution configurations are not covered by this qualification.

Do not infer qualification for GitLab Container Registry, Azure Container Registry, Harbor, Artifactory, Nexus, or another OCI product from protocol similarity. A new path needs the same Rootform profile checks before it can carry a locked selection.

Required registry behavior

Rootform needs manifest resolution by version tag during publication and review, manifest and blob reads by exact digest during locked acquisition, and preservation of custom artifactType, config, and layer media types. When publishing, the registry must accept blob uploads and manifest creation, then return the exact manifest bytes for repull. Authentication must work through Docker-compatible credentials when anonymous access is unavailable. Rootform does not need registry catalog or tag listing.

Identity	Role
Version tag	Human review and publication name, such as dialect-<owner>-<version> or policy-pack-<name>-<version>. A tag alone is not the lock identity.
Repository	Tagless OCI location recorded as source.oci.repository in rootform.lock.
manifest_digest	SHA-256 of the exact OCI manifest bytes selected by the lock. A registry that rewrites the manifest breaks this identity.
layer_digest	SHA-256 of the packaged layer bytes, checked separately from the manifest.
content_digest	Identity of the compiled Dialect or Policy Pack content, not a substitute for either OCI digest.

rootform publish reports the repository, tag, digests, and sizes. Review that identity, then record it with rootform add dialects REFERENCE or rootform add policy-packs REFERENCE, which writes the complete pin to rootform.lock. rootform init then requests the recorded repository and manifest digest directly. It does not search tags or choose a newer version. See Locks and vendored content for exact selection and the OCI mirror procedure for moving the same descriptor graph without changing its digests.

Private access and trust roots

Rootform reads Docker config.json from DOCKER_CONFIG or the standard Docker location. Host-specific helpers, a global credential store, or matching auths supply credentials according to the Docker configuration. A configured helper must be installed on PATH; a helper failure does not silently fall back to another identity. Set SSL_CERT_FILE to a bounded PEM bundle when a private certificate authority is required. Invalid trust data fails before Rootform uses an artifact.

Use Container image when credentials must enter a container. --offline on init or vendor forbids registry acquisition, regardless of credential availability.