What’s a user’s API key?

A user’s API key is needed for authentication when a mashup application based on Springnote API accesses users’ information.
Springnote needs an OpenID to sign in, but as for the Springnote API you will need a user’s API key. The reason why you need an API key is that if the password for your OpenID is exposed to others, this will put other services at risk. In this aspect, Springnote user’s API key only works for the Springnote service so that the risk is limited. However, it can still access your Springnote account so that you need to be careful using the key. It is very risky to share or publish your API key. If your key information is exposed, please delete the existing key and request a new key.