sorry may i bother you by asking about the correct syntaxing of a vote operation?
on the github issues page i found this syntax

curl --data '{"jsonrpc": "2.0", "params": ["network_broadcast_api", "broadcast_transaction", [["vote",{"voter":"maxsieg","author":"ura-soul","permlink":"justin-sun-was-only-warned-about-token-freeze-after-buying-steemit-inc-afterall","weight":10000}]],"extensions":[],"signatures":["postingkey"]}]], "id":1, "method":"call"}' https://steemd.minnowsupportproject.org/

on the steem API documentation i found this syntax

curl -s --data '{"jsonrpc":"2.0", "method":"condenser_api.broadcast_transaction", "params":[{"ref_block_num":1097,"ref_block_prefix":2181793527,"expiration":"2016-03-24T18:00:21","operations":[["vote",{"voter":"steemit","author":"alice","permlink":"a-post-by-alice","weight":10000}]],"extensions":[],"signatures":[]}], "id":1}' https://api.steemit.com

which i also could not get to work with responses like

{"jsonrpc":"2.0","id":null,"error":{"code":-32700,"message":"Parse error","data":{"error_id":"7d700d7a-12d4-4657-a211-01054542602c","jussi_request_id":"000162206875925053"}}}

also not sure why expiration and block refference/prefix is needed for a vote operation....