vsphere-mcp-extended

An add-on that extends vsphere-mcp-server (an MCP server for VMware vCenter) with a much larger tool surface, built on top of it without modifying the installed package.

vsphere-mcp-server talks to vCenter's REST API, which is read-only inventory plus basic power operations and doesn't expose live performance counters. This add-on imports the base package's FastMCP instance and registers additional tools on it using pyVmomi (vCenter's SOAP API), which unlocks real-time and historical performance data plus a large set of write operations.

What it adds

Performance & monitoring

• get_vm_performance — live CPU/memory/ballooning/swap stats for one VM

• get_vm_disk_performance — live per-disk IOPS, latency, throughput

• list_vm_performance — bulk snapshot across all VMs in a single API round trip, sorted by CPU usage, flags VMs under memory pressure

• get_vm_performance_history — historical min/avg/p95/max over N days (CPU%, CPU ready%, memory%, swap, disk latency, network) using vCenter's rolled-up historical intervals — the right tool for "is this VM actually bottlenecked, and on what"

VM lifecycle

• create_vm — create a new VM (datastore, cluster, network, disk, guest OS type)

• reconfigure_vm_resources — change vCPU / RAM on an existing VM

• add_vm_disk, get_vm_disks, resize_vm_disk — disk management

• get_vm_network — reliably resolve the actual portgroup a VM's NIC is on (the base package's REST tool often reports "Unknown")

Snapshots

• list_vm_snapshots, list_all_vm_snapshots (bulk scan across all VMs)

• create_vm_snapshot, remove_vm_snapshot, revert_vm_snapshot

Content Library / ISOs

• find_content_library_item, get_content_library_item_files

• browse_datastore — read-only datastore browsing, useful for resolving real on-disk paths before mounting

• mount_iso — attach a Content Library ISO to a VM's CD-ROM

Hosts, clusters & networking

• list_cluster_hosts

• add_portgroup_to_host, add_portgroup_to_cluster — create standard-vSwitch portgroups (per-host is more robust for large clusters; the cluster-wide version isolates failures per host instead of aborting the batch)

• migrate_vm_host — relocate/vMotion a VM to a different host

• diagnose_vm_datastore_access — check whether a VM's current host can actually see a given datastore (useful when device reconfigures fail with "backing file is not accessible from host")

All tools are read-only except: create_vm, reconfigure_vm_resources, add_vm_disk, resize_vm_disk, mount_iso, create_vm_snapshot, remove_vm_snapshot, revert_vm_snapshot, migrate_vm_host, add_portgroup_to_host, add_portgroup_to_cluster.

Related MCP server: vmware-storage

Install

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Credentials are handled entirely by vsphere-mcp-server's own credential store (macOS Keychain on macOS, with a GUI prompt on first use / expiry). This add-on does not read or store credentials itself — it calls the base package's get_credentials(hostname).

Run

Run this file instead of python -m vsphere_mcp_server.server:

python vsphere_perf_addon.py

It registers every tool from the base package plus everything listed above on the same server instance.

Use with Claude Desktop

Add to claude_desktop_config.json (Settings → Developer → Edit Config):

{
  "mcpServers": {
    "vsphere": {
      "command": "/absolute/path/to/.venv/bin/python",
      "args": ["/absolute/path/to/vsphere_perf_addon.py"]
    }
  }
}

Restart Claude Desktop afterwards.

Notes / gotchas

• Credential expiry: the base package's macOS Keychain cache has a TTL (commonly ~4 hours). When it expires, a native GUI password prompt appears that only a human can fill in — any in-flight tool call will hang until it's filled or times out. If you see a timeout or "authentication failed" from a client automating this server, have a human fill in the OS prompt, then retry.

• Historical performance granularity: get_vm_performance_history depends on which historical intervals are enabled/retained on your vCenter (Configure → General → Statistics). Disk latency at longer rollups (weekly/monthly) is often not collected unless the statistics level is raised — CPU/memory/network usually are.

• Bulk operations: list_vm_performance and list_all_vm_snapshots use a single PropertyCollector.RetrieveContents call regardless of VM count, so they stay fast with hundreds of VMs. Prefer these over looping get_vm_performance per VM.

• create_vm / add_portgroup_to_cluster on large batches: creating multiple VMs in parallel can occasionally hit a transient vim.fault.CannotAccessFile; retrying the single failed call usually succeeds. For portgroup rollout across many hosts, add_portgroup_to_host (single host) isolates failures better than the cluster-wide call, which can time out on a large cluster.

Requirements

• Python 3.9+

• A vCenter service account with at least: VM read/write privileges for the mutating tools you plan to use, Content Library → Read, and read access to hosts/datastores/networks.

• vsphere-mcp-server and pyvmomi (see requirements.txt)

License

MIT — see LICENSE.