When I use ETH with JSON-RPC I have error "message": "authentication needed: password or unlock» and If I manually unlock I have other error "message": "insufficient funds for gas * price + value" Any ideas???? POST request
You need to pass --rpc and also pass required apis through --rpcapi on the command line to enable it, as per https://github.com/ethereum/wiki/wiki/JSON-RPC#go.
First of all it would be better to avoid unlocking account, second - "insufficient funds for gas * price + value" means that your account doesn't have enough balance to perform the transaction.
The message says that your account's balance is lower than (
gas limit *
gas price), which is often more than a transaction actually takes, because the maximum gas allowance (
gas limit) is what matters here.