The get_raw_transaction method takes coin and tx_hash as input, and returns the full signed raw transaction hex for any transaction that is confirmed or within the mempool.
{"mmrpc":"2.0","error":"No such coin KMD","error_path":"lp_coins","error_trace":"lp_coins:2234] lp_coins:2156]","error_type":"NoSuchCoin","error_data":{"coin":"KMD"},"id":0}