Cloudpinyin is Fcitx addon that will add one candidate word to your pinyin list. It current support four provider, Sogou, QQ, Baidu, Google. By default the trigger length is 10, you can set it shorter. And it use a memory-based cache to cache recent result.
When you are using any pinyin related input method, when your pinyin string length is over the threshold, it will send a request the provider server and fetch the result back. There will be a place holder "..." when the word is loading.
If the word is already appeared in the candidate list, it will be removed.
Set HTTP proxy
export http_proxy=http://ip:port export https_proxy=http://ip:port
Before Fcitx run.
Potential Security Issue
In spite of Google, all providers do not support SSL (by the way, you need to update to 0.2.1 to use SSL with Google), and you might not trust the provider, since the data you typed might have some private info. So think about it before use cloudpinyin.