create droplet from snapshot by REST api

Can you share the API call you actually made and the error message that was returned? It would help us figure out what’s going on here.

To launch a new droplet based on a snapshot, you need to supply it’s ID for the image parameter:

curl -X POST -H 'Content-Type: application/json' \
    -H 'Authorization: Bearer $TOKEN' -d \
    '{"name":"example.com","region":"nyc3","size":"512mb","image": 12345}' \
    "https://api.digitalocean.com/v2/droplets" 

{
    "droplet": {
        "id": 3622537,
        "name": "peer1.ethergit.com",
        "memory": 512,
        "vcpus": 1,
        "disk": 20,
        "locked": true,
        "status": "new",
        "kernel": {
            "id": 2233,
            "name": "Ubuntu 14.04 x64 vmlinuz-3.13.0-37-generic",
            "version": "3.13.0-37-generic"
        },
        "created_at": "2014-12-30T21:43:03Z",
        "features": [
            "virtio"
        ],
        "backup_ids": [],
        "snapshot_ids": [],
        "image": {},
        "size_slug": "512mb",
        "networks": {},
        "region": {}
    },
    "links": {
        "actions": [
            {
                "id": 40095737,
                "rel": "create",
                "href": "https://api.digitalocean.com/v2/actions/40095737"
            }
        ]
    }
}

nop, the droplet was created, it just was an empty droplet not a snapshot image.