rancher-mcp-server

Model Context Protocol (MCP) server for the Rancher ecosystem: multi-cluster Kubernetes, Harvester HCI (VMs, storage, networks), and Fleet GitOps.

Demo

A walkthrough of how this MCP server works (example in Cursor).

https://github.com/user-attachments/assets/7d8fb814-e504-47b4-956d-28f43aeea3b8

Features

• Harvester toolset: List/get VMs, images, volumes, networks, hosts; VM actions; addon list/switch (enable/disable)
• Rancher toolset: List clusters and projects, cluster get, overview (management API)
• Kubernetes toolset: List/get/create/patch/delete resources by apiVersion/kind; describe (resource + events), events, capacity
• Helm toolset: List/get/history of releases; install, upgrade, rollback, uninstall; repo list
• Fleet toolset: GitRepo list/get/create; Bundle list; Fleet cluster list; drift detection
• Rancher Steve API: Single token, multi-cluster access; no CLI wrappers
• Security: Read-only default, disable-destructive, sensitive data masking
• Config: Flags, env (RANCHER_MCP_*), or file (YAML/TOML)

Quick start

Install

npm install -g rancher-mcp-server

Cursor

Add to .cursor/mcp.json (project-level) or ~/.cursor/mcp.json (global):

{
  "mcpServers": {
    "rancher": {
      "command": "npx",
      "args": [
        "-y", "rancher-mcp-server",
        "--rancher-server-url", "https://rancher.example.com",
        "--rancher-token", "token-xxxxx:yyyy",
        "--toolsets", "harvester,rancher,kubernetes,fleet"
      ]
    }
  }
}

Restart Cursor after saving. Check Settings → Tools & MCP that rancher is listed and enabled.

Claude Desktop

Add to your Claude Desktop config (claude_desktop_config.json):

{
  "mcpServers": {
    "rancher": {
      "command": "npx",
      "args": [
        "-y", "rancher-mcp-server",
        "--rancher-server-url", "https://rancher.example.com",
        "--rancher-token", "token-xxxxx:yyyy",
        "--toolsets", "harvester,rancher,kubernetes,fleet"
      ]
    }
  }
}

With env vars instead of args

If you prefer to keep the token out of the JSON config:

{
  "mcpServers": {
    "rancher": {
      "command": "npx",
      "args": ["-y", "rancher-mcp-server"],
      "env": {
        "RANCHER_MCP_RANCHER_SERVER_URL": "https://rancher.example.com",
        "RANCHER_MCP_RANCHER_TOKEN": "token-xxxxx:yyyy",
        "RANCHER_MCP_TOOLSETS": "harvester,rancher,kubernetes"
      }
    }
  }
}

Enable write operations

For VM create, snapshots, backups, image/volume create, addon switch, host maintenance mode, VPC create/update/delete, Kubernetes create/patch/delete, Helm install/upgrade/rollback, and Fleet gitrepo create/delete, add --read-only=false. Delete operations also require --disable-destructive=false (default).

{
  "mcpServers": {
    "rancher": {
      "command": "npx",
      "args": [
        "-y", "rancher-mcp-server",
        "--rancher-server-url", "https://rancher.example.com",
        "--rancher-token", "token-xxxxx:yyyy",
        "--toolsets", "harvester,rancher,kubernetes,helm,fleet",
        "--read-only=false"
      ]
    }
  }
}

HTTP/SSE transport

For web clients or remote access, add --transport and --port:

{
  "mcpServers": {
    "rancher": {
      "command": "npx",
      "args": [
        "-y", "rancher-mcp-server",
        "--rancher-server-url", "https://rancher.example.com",
        "--rancher-token", "token-xxxxx:yyyy",
        "--transport", "http",
        "--port", "8080"
      ]
    }
  }
}

The server exposes the MCP endpoint over HTTP/SSE (e.g. http://localhost:8080/sse).

Build from source

If you prefer to build the Go binary yourself:

go build -o rancher-mcp-server ./cmd/rancher-mcp-server

Then reference the binary directly in your MCP config:

{
  "mcpServers": {
    "rancher": {
      "command": "/absolute/path/to/rancher-mcp-server",
      "args": [
        "--rancher-server-url", "https://rancher.example.com",
        "--rancher-token", "token-xxxxx:yyyy",
        "--toolsets", "harvester,rancher,kubernetes,fleet"
      ]
    }
  }
}

---

Configuration

Option	Env	Default	Description
--rancher-server-url	RANCHER_MCP_RANCHER_SERVER_URL	—	Rancher server URL (required)
--rancher-token	RANCHER_MCP_RANCHER_TOKEN	—	Bearer token (required)
--tls-insecure	RANCHER_MCP_TLS_INSECURE	false	Skip TLS verification
--read-only	RANCHER_MCP_READ_ONLY	true	Disable write operations
--disable-destructive	RANCHER_MCP_DISABLE_DESTRUCTIVE	false	Disable delete operations
--toolsets	RANCHER_MCP_TOOLSETS	harvester	Toolsets to enable: harvester, rancher, kubernetes, helm, fleet
--transport	RANCHER_MCP_TRANSPORT	stdio	Transport: stdio or http (HTTP/SSE)
--port	RANCHER_MCP_PORT	0	Port for HTTP/SSE (0 = stdio only)

---

Harvester tools

Tool	Description
harvester_vm_list	List VMs with status, namespace, spec/status
harvester_vm_get	Get one VM (full spec and status)
harvester_vm_action	start, stop, restart, pause, unpause, migrate
harvester_vm_create	Create VM (when not read-only). Supports network, interface_type (managedtap/bridge/masquerade), subnet for KubeOVN VPC.
harvester_vm_snapshot	Create/list/restore/delete VM snapshots
harvester_vm_backup	Create/list/restore VM backups (Backup Target)
harvester_image_list	List VM images (VirtualMachineImage)
harvester_image_create	Create VM image from URL (when not read-only)
harvester_volume_list	List PVCs (Longhorn-backed volumes)
harvester_volume_create	Create volume/PVC (optionally from image)
harvester_network_list	List VM networks (NetworkAttachmentDefinition)
harvester_network_create	Create VM network - KubeOVN overlay or VLAN (when not read-only)
harvester_network_update	Update VM network config (when not read-only)
harvester_network_delete	Delete VM network (when destructive allowed)
harvester_subnet_list	List KubeOVN Subnets (requires kubeovn-operator)
harvester_subnet_create	Create Subnet in VPC for VM network (when not read-only)
harvester_subnet_update	Update Subnet namespaces/NAT (when not read-only)
harvester_subnet_delete	Delete Subnet (when destructive allowed)
harvester_host_list	List nodes (Harvester hosts)
harvester_host_action	Enable/disable maintenance mode on a host (cordon/uncordon)
harvester_settings	List or get Harvester cluster settings (backup-target, etc.)
harvester_addon_list	List Harvester addons (enabled/disabled state)
harvester_addon_switch	Enable or disable an addon (when not read-only)
harvester_vpc_list	List KubeOVN VPCs (requires kubeovn-operator addon)
harvester_vpc_create	Create a KubeOVN VPC (when not read-only)
harvester_vpc_update	Update a KubeOVN VPC namespaces (when not read-only)
harvester_vpc_delete	Delete a KubeOVN VPC (when destructive allowed)

List tools accept cluster (required), namespace, format (json|table), limit (default 100), continue (pagination token for next page). Write tools require read_only: false.

Creating a VM on KubeOVN VPC with external internet

Use harvester_vm_create with:

1. network: Name of the overlay network (NAD) linked to a KubeOVN subnet. Create via harvester_network_create (type=kubeovn) then harvester_subnet_create with provider={network}.{namespace}.ovn, vpc=<vpc-name>, and nat_outgoing=true.
2. interface_type: managedtap (recommended for KubeOVN) or bridge. Uses Multus as primary network.
3. subnet: Optional KubeOVN subnet name for ovn.kubernetes.io/logical_switch annotation.

Example: VM on network vswitch1 in namespace default, managedTap interface, subnet vswitch1-subnet:

harvester_vm_create cluster=<cluster-id> namespace=default name=testvm image=<image> network=vswitch1 interface_type=managedtap subnet=vswitch1-subnet

Rancher tools

Tool	Description
rancher_cluster_list	List Rancher clusters (management)
rancher_cluster_get	Get one cluster (health, version, node count)
rancher_project_list	List Rancher projects
rancher_overview	Overview: cluster count and project count

Uses Rancher management API (cluster ID local). No cluster param.

Helm tools

Tool	Description
helm_list	List Helm releases (optionally by namespace, deployed/failed/pending)
helm_get	Get release details (manifest, values, notes)
helm_history	Get revision history for a release
helm_repo_list	List configured Helm chart repositories (from local config)
helm_install	Install a Helm chart (when not read-only)
helm_upgrade	Upgrade a Helm release (when not read-only)
helm_rollback	Rollback a release to a previous revision (when not read-only)
helm_uninstall	Uninstall a release (when destructive allowed)

All tools take cluster (Rancher cluster ID). Install/upgrade require chart, release; optional repo_url, version, values (JSON).

Fleet tools

Tool	Description
fleet_gitrepo_list	List Fleet GitRepos (GitOps sources)
fleet_gitrepo_get	Get one GitRepo (spec, status)
fleet_gitrepo_create	Create a GitRepo (when not read-only)
fleet_gitrepo_delete	Delete a GitRepo (when destructive allowed)
fleet_gitrepo_action	Pause, unpause, disablePolling, enablePolling, forceUpdate
fleet_gitrepo_clone	Clone a GitRepo to a new name (copy spec)
fleet_bundle_list	List Fleet Bundles (deployment units from GitRepos)
fleet_cluster_list	List Fleet clusters (downstream clusters registered with Fleet)
fleet_drift_detect	Report BundleDeployments with Modified state (drift)

All tools use the Rancher management cluster (local). Optional namespace (default: fleet-default). List tools support format, limit, continue (pagination). fleet_gitrepo_create requires name, repo; optional branch, paths. fleet_gitrepo_action supports: pause, unpause, disablePolling, enablePolling, forceUpdate. fleet_gitrepo_clone copies spec from an existing GitRepo to a new name.

Kubernetes tools

Tool	Description
kubernetes_list	List resources by apiVersion/kind (e.g. v1 Pod, apps/v1 Deployment)
kubernetes_get	Get one resource by apiVersion, kind, namespace, name
kubernetes_describe	Get resource + recent events
kubernetes_events	List events in a namespace (optional involvedObject filter)
kubernetes_capacity	Node capacity/allocatable summary per node
kubernetes_create	Create resource from JSON (when not read-only)
kubernetes_patch	Patch resource with JSON (when not read-only)
kubernetes_delete	Delete resource (when destructive allowed)

All tools take cluster (Rancher cluster ID). List/get support namespace, format (json|table), limit, continue (pagination). Create/patch/delete are gated by read_only and disable_destructive.

---

Setup: Rancher token & Harvester cluster ID

Get a Rancher API token

1. Log in to your Rancher UI.
2. Click your profile/avatar (top right) → Account & API Keys (or API & Keys).
3. Click Create API Key, name it (e.g. mcp-server), then Create.
4. Copy the token once (format like token-abc12:xyz...). Use it as --rancher-token or RANCHER_MCP_RANCHER_TOKEN.

Find your Harvester cluster ID

Harvester tools require the cluster ID (e.g. c-tx8rn) on each call.

• From Rancher UI: Go to Cluster Management → open your Harvester cluster. The URL contains the cluster ID: .../c/<cluster-id>/....
• From API: curl -s -H "Authorization: Bearer YOUR_TOKEN" "https://YOUR_RANCHER_URL/v1/management.cattle.io.clusters" | jq '.data[] | {name: .metadata.name}'

---

Docker (HTTP/SSE only)

For HTTP/SSE server mode, use the container image from GitHub Container Registry (ghcr.io). For Cursor/Claude with stdio, use npm (see Quick start).

Run the server in SSE mode and expose the port:

docker run -d -p 8080:8080 \
  -e RANCHER_MCP_RANCHER_SERVER_URL=https://rancher.example.com \
  -e RANCHER_MCP_RANCHER_TOKEN="token-xxxxx:yyyy" \
  -e RANCHER_MCP_TRANSPORT=http \
  -e RANCHER_MCP_PORT=8080 \
  ghcr.io/mrostamii/rancher-mcp-server:latest

Connect Cursor or Claude Desktop via the SSE URL: http://localhost:8080/sse

Supported platforms

• macOS (Apple Silicon & Intel)
• Linux (x64 & ARM64)
• Windows (x64)

---

Troubleshooting

Issue	What to check
"rancher-server-url and rancher-token are required"	Check --rancher-server-url and --rancher-token in args, or env vars RANCHER_MCP_RANCHER_SERVER_URL and RANCHER_MCP_RANCHER_TOKEN.
401 Unauthorized	Token expired or invalid. Create a new API key in Rancher.
TLS / certificate errors	For self-signed Rancher, pass --tls-insecure (dev only).
"cluster not found" or empty lists	Wrong cluster ID. Get it from Rancher UI URL or API; pass it as cluster to Harvester/Kubernetes tools.
Cursor doesn't show tools	Restart Cursor after editing mcp.json; check Tools & MCP that the server is enabled.
Binary not found	Use absolute paths in mcp.json for command when building from source.

---

License

Apache-2.0