Rudder

It's not possible to reject a pending node with API:

root@server:~# curl -k -H "X-API-Token: PojCJDhajkGqVx1TTmiZKNFZORKOYc8X" -X GET https://localhost/rudder/api/4/nodes/7b13f54f-7ab6-4a45-ada7-9049039b87ca?prettify=true 
{
  "action": "nodeDetails",
  "id": "7b13f54f-7ab6-4a45-ada7-9049039b87ca",
  "result": "success",
  "data": {
    "nodes": [
      {
        "architectureDescription": "x86_64-linux-thread-multi",
        "hostname": "node5",
        "managementTechnology": [
          {
            "name": "CFEngine Community" 
          }
        ],
        "status": "pending",
        "machine": {
          "id": "5A933D95-8C69-479B-AD8B-62373998E47B",
          "type": "Virtual",
          "provider": "vbox" 
        },
        "id": "7b13f54f-7ab6-4a45-ada7-9049039b87ca",
        "ipAddresses": [
          "127.0.0.1",
          "10.0.2.15",
          "192.168.42.15" 
        ],
        "ram": 244,
        "os": {
          "type": "Linux",
          "name": "Debian",
          "version": "6.0.4",
          "fullName": "Debian GNU/Linux 6.0.4 (squeeze)",
          "kernelVersion": "2.6.32-5-amd64" 
        },
        "lastInventoryDate": "2014-07-31 15:57",
        "policyServerId": "root" 
      }
    ]
  }
}

root@server:~# curl -k -H "X-API-Token: PojCJDhajkGqVx1TTmiZKNFZORKOYc8X" -X DELETE https://localhost/rudder/api/latest/nodes/7b13f54f-7ab6-4a45-ada7-9049039b87ca?prettify=true {
  "action": "changePendingNodeStatus",
  "result": "error",
  "errorDetails": "Node with ID '7b13f54f-7ab6-4a45-ada7-9049039b87ca' was not found" 
}