> ## Documentation Index > Fetch the complete documentation index at: https://docs.chkk.io/llms.txt > Use this file to discover all available pages before exploring further. # Get Reference > Gets a single OCIReference An OCIReference represents a relationship between an OCITag and an OCIArtifact. When attempting to match a customer's container image to a known OCIArtifact, we look up an OCITag that matches a particular digest. For mutable OCITags, that digest association, however, changes over time. Until OCIReference was introduced, we were only storing the first known digest for these mutable tags, which ended up introducing a lot of stale data into the digest classification process: the classifiers were not able to find OCITags that match newer digests for these mutable tags and therefore less accurate classifiers like ruleset and deduction classifier needed to try and classify the cluster inventory record. For OCITags that are mutable -- e.g. "latest" or "stable" or "v1" -- there can be many digests that an OCITag has previously pointed to. Previously-referred digests for an OCITag are made available through the OCIReference object model. You may be wondering why we don't have an References field on OCITag that just returns the digests that have been previously associated with this OCITag. The reason for that is because the list of previously-known digest associations can be very long (it's unbounded) and so having this information in a separately-fetched object model that can be paginated/controlled seemed like a better design. ## OpenAPI ````yaml get /ocireferences/{reference}/ openapi: 3.1.0 info: description: > The Chkk Artifact Register API exposes information about the artifacts in a customer's clusters. Data models exposed in the Chkk Artifact Register API include: * Organization: the top-level object that models a Chkk customer. * Account: a container for resource ownership within an Organization. * KubePlatform: describes things like the cloud infrastructure provider and the control plane provider. * KubeCluster: a single cluster provisioned by a KubePlatform. * KubeClusterScan: a single Chkk scan of a cluster. * KubeClusterResource: a single Resource (Deployment, DaemonSet or StatefulSet) from a KubeClusterScan. * KubeClusterResourceContainer: a single container record in a KubeClusterResource. * Project: software that provides some functionality. * ProjectReleaseSeries: a single release series for a Project. * ProjectRelease: a single release for a Project. * ProjectVersionSet: a configuration, layout or structure of a Project that is consistent for a range of ProjectReleases. * ProjectComponent: a separate binary, daemon, or subsystem of a Project. * Package: a named bundle of software that is bundled (and identified) in the format of a specific PackageSystem. * PackageRelease: a single release for a Package. * PackageVersionSet: a configuration, layout or structure of a Package that is consistent for a range of PackageReleases. * OCIRepository: a single namespace within an OCI Registry. * OCIArtifact: a single OCI Artifact (manifest) that describes an OCI Image or other OCI Artifact. * OCITag: a name that points to a unique OCIArtifact within an OCIRepository. * OCIReference: a relationship between an OCITag and an OCIArtifact. * RiskSignature: the source of a potential availability or operational risk for a customer. * Risk: a detected RiskSignature for an Account. * UpgradeTemplate: detailed instructions for upgrading or migrating a KubeCluster or an installed part of a KubeCluster. title: Chkk API version: '1.0' servers: [] security: [] paths: /ocireferences/{reference}/: get: tags: - OCI summary: Get Reference description: > Gets a single OCIReference An OCIReference represents a relationship between an OCITag and an OCIArtifact. When attempting to match a customer's container image to a known OCIArtifact, we look up an OCITag that matches a particular digest. For mutable OCITags, that digest association, however, changes over time. Until OCIReference was introduced, we were only storing the first known digest for these mutable tags, which ended up introducing a lot of stale data into the digest classification process: the classifiers were not able to find OCITags that match newer digests for these mutable tags and therefore less accurate classifiers like ruleset and deduction classifier needed to try and classify the cluster inventory record. For OCITags that are mutable -- e.g. "latest" or "stable" or "v1" -- there can be many digests that an OCITag has previously pointed to. Previously-referred digests for an OCITag are made available through the OCIReference object model. You may be wondering why we don't have an References field on OCITag that just returns the digests that have been previously associated with this OCITag. The reason for that is because the list of previously-known digest associations can be very long (it's unbounded) and so having this information in a separately-fetched object model that can be paginated/controlled seemed like a better design. operationId: oci-reference-get responses: '200': content: application/json: schema: $ref: '#/components/schemas/OCIReference' description: OK default: content: application/problem+json: schema: $ref: '#/components/schemas/ErrorModel' description: Error components: schemas: OCIReference: additionalProperties: false properties: $schema: description: A URL to the JSON Schema for this object. examples: - https://example.com/schemas/OCIReference.json format: uri readOnly: true type: string artifact: description: >- Artifact is the ID (the digest) of the OCIArtifact this OCIReference pointed to. examples: - ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad type: string created_by: description: user who created the record. type: string created_on: description: timestamp of when the record was created. format: date-time type: string last_modified_by: description: user who last modified the record. type: string last_modified_on: description: timestamp of when the record was last modified. format: date-time type: string tag: description: >- Tag is the *full* URL-like ID of the OCITag that this OCIReference points to. examples: - docker.io/cert-manager/cert-manager:latest type: string required: - tag - artifact - created_by - created_on - last_modified_by - last_modified_on type: object ErrorModel: additionalProperties: false properties: $schema: description: A URL to the JSON Schema for this object. examples: - https://example.com/schemas/ErrorModel.json format: uri readOnly: true type: string detail: description: >- A human-readable explanation specific to this occurrence of the problem. examples: - Property foo is required but is missing. type: string errors: description: Optional list of individual error details items: $ref: '#/components/schemas/ErrorDetail' type: - array - 'null' instance: description: >- A URI reference that identifies the specific occurrence of the problem. examples: - https://example.com/error-log/abc123 format: uri type: string status: description: HTTP status code examples: - 400 format: int64 type: integer title: description: >- A short, human-readable summary of the problem type. This value should not change between occurrences of the error. examples: - Bad Request type: string type: default: about:blank description: A URI reference to human-readable documentation for the error. examples: - https://example.com/errors/example format: uri type: string type: object ErrorDetail: additionalProperties: false properties: location: description: >- Where the error occurred, e.g. 'body.items[3].tags' or 'path.thing-id' type: string message: description: Error message text type: string value: description: The value at the given location type: object ````