OCI

The OCI module implements a client for the OCI Distribution Specification, used for interacting with GitHub Container Registry (GHCR).

Media types

const GREKT_MEDIA_TYPES = {
  manifest: "application/vnd.oci.image.manifest.v1+json",
  config: "application/vnd.grekt.artifact.config.v1+json",
  layer: "application/vnd.grekt.artifact.layer.v1.tar+gzip",
} as const

OCI types

OciDescriptor

interface OciDescriptor {
  mediaType: string
  digest: string          // e.g., sha256:abc123...
  size: number
  annotations?: Record<string, string>
}

OciManifest

interface OciManifest {
  schemaVersion: 2
  mediaType: string
  config: OciDescriptor
  layers: OciDescriptor[]
  annotations?: Record<string, string>
}

OciClient

class OciClient {
  constructor(config: OciRegistryConfig, http: HttpClient)

  async ping(): Promise<boolean>
  async pullManifest(name: string, reference: string): Promise<PullManifestResult>
  async pullBlob(name: string, digest: string): Promise<PullBlobResult>
  async listTags(name: string): Promise<ListTagsResult>
  async tagExists(name: string, tag: string): Promise<boolean>
  async pullArtifactLayer(name: string, tag: string): Promise<PullBlobResult>
}

Methods

Method	Description
ping	Check if the registry is accessible
pullManifest	Retrieve an OCI manifest by name and reference (tag or digest)
pullBlob	Download a blob by its digest
listTags	List all tags for a repository
tagExists	Check if a specific tag exists
pullArtifactLayer	Convenience method that pulls the manifest and then downloads the artifact layer

The OciClient is used internally by GitHubRegistryClient for pull operations. Push operations use the oras CLI tool via ShellExecutor.