Hetzner Cloud MCP Server

Instructions

Create a new volume.

Creates a new volume with the specified configuration.

Examples:
- Basic volume: {"name": "data-volume", "size": 10}
- With location: {"name": "db-volume", "size": 100, "location": "fsn1"}
- Attached to server: {"name": "app-volume", "size": 50, "server": 123456, "automount": true}
- With format: {"name": "log-volume", "size": 20, "format": "ext4"}

Implementation Reference

• mcp_hetzner/server.py:219-227 (schema)

  Pydantic BaseModel defining the input parameters and validation for the create_volume tool.

  class CreateVolumeParams(BaseModel):
      name: str = Field(..., description="Name of the volume")
      size: int = Field(..., description="Size of the volume in GB (min 10, max 10240)")
      location: Optional[str] = Field(None, description="Location where the volume will be created (e.g., nbg1, fsn1)")
      server: Optional[int] = Field(None, description="ID of the server to attach the volume to")
      automount: Optional[bool] = Field(False, description="Auto-mount the volume after attaching it")
      format: Optional[str] = Field(None, description="Filesystem format (e.g., xfs, ext4)")
      labels: Optional[Dict[str, str]] = Field(None, description="User-defined labels (key-value pairs)")

• mcp_hetzner/server.py:997-1068 (handler)

  The primary handler function decorated with @mcp.tool(), implementing the create_volume tool logic: validates inputs, resolves location and server objects, calls Hetzner Cloud API to create volume, handles response and formats output including volume details, action status, and next actions.

  @mcp.tool()
  def create_volume(params: CreateVolumeParams) -> Dict[str, Any]:
      """
      Create a new volume.
      
      Creates a new volume with the specified configuration.
      
      Examples:
      - Basic volume: {"name": "data-volume", "size": 10}
      - With location: {"name": "db-volume", "size": 100, "location": "fsn1"}
      - Attached to server: {"name": "app-volume", "size": 50, "server": 123456, "automount": true}
      - With format: {"name": "log-volume", "size": 20, "format": "ext4"}
      """
      try:
          # Get location if provided
          location = None
          if params.location:
              location = client.locations.get_by_name(params.location)
              if not location:
                  return {"error": f"Location '{params.location}' not found"}
          
          # Get server if provided
          server = None
          if params.server:
              server = client.servers.get_by_id(params.server)
              if not server:
                  return {"error": f"Server with ID {params.server} not found"}
          
          # Create the volume
          response = client.volumes.create(
              name=params.name,
              size=params.size,
              location=location,
              server=server,
              automount=params.automount,
              format=params.format,
              labels=params.labels
          )
          
          # Extract volume and action information
          volume = response.volume
          action = response.action
          next_actions = response.next_actions
          
          # Format the response
          return {
              "volume": volume_to_dict(volume),
              "action": {
                  "id": action.id,
                  "status": action.status,
                  "command": action.command,
                  "progress": action.progress,
                  "error": action.error,
                  "started": action.started.isoformat() if action.started else None,
                  "finished": action.finished.isoformat() if action.finished else None,
              } if action else None,
              "next_actions": [
                  {
                      "id": next_action.id,
                      "status": next_action.status,
                      "command": next_action.command,
                      "progress": next_action.progress,
                      "error": next_action.error,
                      "started": next_action.started.isoformat() if next_action.started else None,
                      "finished": next_action.finished.isoformat() if next_action.finished else None,
                  }
                  for next_action in next_actions
              ] if next_actions else None,
          }
      except Exception as e:
          return {"error": f"Failed to create volume: {str(e)}"}

• mcp_hetzner/server.py:82-98 (helper)

  Helper function used by create_volume (and other volume tools) to serialize Volume domain objects into JSON-friendly dictionaries for the tool response.

  def volume_to_dict(volume: Volume) -> Dict[str, Any]:
      """Convert a Volume object to a dictionary with relevant information."""
      return {
          "id": volume.id,
          "name": volume.name,
          "size": volume.size,
          "location": volume.location.name if volume.location else None,
          "server": volume.server.id if volume.server else None,
          "linux_device": volume.linux_device,
          "protection": {
              "delete": volume.protection["delete"] if volume.protection else False,
          },
          "labels": volume.labels,
          "format": volume.format,
          "created": volume.created.isoformat() if volume.created else None,
          "status": volume.status,
      }