The official API definitions and client libraries for Open Cluster Management (OCM), a CNCF sandbox project focused on multicluster and multicloud scenarios for Kubernetes.

This repository serves as the canonical source for all Open Cluster Management API definitions and generated client libraries. It contains API types, CRDs, client code, and helper utilities, making it lightweight and easy for external projects to import and integrate with OCM.

• Easy Integration: External projects can import OCM APIs without pulling in implementation dependencies
• API Definitions: Single source of truth for all OCM Custom Resource Definitions (CRDs)
• Generated Clients: Kubernetes-style typed clients for all OCM APIs
• Lightweight: No core controllers or operators, just APIs and helper utilities

This repository defines four main API groups that cover the complete OCM ecosystem:

Manage cluster lifecycle, registration, and placement across your fleet. The v1 APIs provide core cluster registration and grouping with ManagedCluster, ManagedClusterSet, and ManagedClusterSetBinding. The v1beta1 APIs offer advanced cluster selection and placement with Placement and PlacementDecision. The v1alpha1 APIs include cluster capabilities and scoring through ClusterClaim and AddonPlacementScore.

Deploy and manage Kubernetes resources across multiple clusters. The v1 APIs provide ManifestWork and AppliedManifestWork to deploy any Kubernetes resource to managed clusters. The v1alpha1 APIs include ManifestWorkReplicaSet for bulk deployment across cluster sets.

Build and manage extensions on top of the OCM foundation. The v1alpha1 APIs provide addon lifecycle and configuration through ClusterManagementAddOn, ManagedClusterAddOn, and AddonDeploymentConfig.

Install and configure OCM components. The v1 APIs provide ClusterManager and Klusterlet for hub and agent installation and configuration.

Add this module to your Go project:

go get open-cluster-management.io/api@latest

import (
    clusterv1 "open-cluster-management.io/api/cluster/v1"
    clusterclientset "open-cluster-management.io/api/client/cluster/clientset/versioned"
)

// Create a client
client := clusterclientset.NewForConfigOrDie(config)

// List all managed clusters
clusters, err := client.ClusterV1().ManagedClusters().List(ctx, metav1.ListOptions{})

// Create a new managed cluster
cluster := &clusterv1.ManagedCluster{
    ObjectMeta: metav1.ObjectMeta{
        Name: "my-cluster",
    },
    Spec: clusterv1.ManagedClusterSpec{
        HubAcceptsClient: true,
    },
}

api/
├── addon/           # Addon management APIs
├── cluster/         # Cluster management APIs  
├── operator/        # Operator APIs
├── work/            # Work distribution APIs
├── client/          # Generated Kubernetes clients for all APIs
└── utils/           # Utility libraries

These projects implement the APIs defined in this repository:

• registration: Implements ManagedCluster and cluster lifecycle
• work: Implements ManifestWork for resource distribution
• placement: Implements Placement for intelligent cluster selection
• addon-framework: Implements addon management APIs
• registration-operator: Implements operator APIs

This API library is designed for external projects that want to:

• Build OCM-compatible controllers and operators
• Integrate with OCM clusters from existing platforms
• Create custom tools for multicluster management
• Develop addons and extensions for OCM

• Go 1.23+
• Kubernetes 1.28+

# Update generated code
make update

# Verify code generation and formatting  
make verify

# Run tests
make test

This repository uses Kubernetes code generators to create:

• DeepCopy methods: For all API types
• Typed clients: Kubernetes-style clientsets
• Informers and listers: For efficient caching and watching
• OpenAPI schemas: For CRD validation

We welcome contributions! Please see our Contributing Guide for details.

Connect with the OCM community:

• Website
• Slack
• Mailing group
• Community meetings
• YouTube channel

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

Open Cluster Management is a Cloud Native Computing Foundation sandbox project.