Under the Authentication section on https://api.stackexchange.com/docs/js-lib, there are a few typos (emphasis mine):

scope (optional) – an array of scopes to request during authentication, valid scopes are in the authentication documentaiton.

documentaiton => documentation

If networkUsers was not passed to SE.authenticate networkUsers will not bet set, if set it is an array of network_user objects.

not bet set => not be set

Under the Errors section:

Note that the user reject an application is conceptually an error.

the user reject => the user rejecting

Under the Unregistered Users section:

We want to provide this data, but we also want to be able to shut down scrappers who aren't following our attribution terms

scrappers => scrapers

Also, this isn't a typo, but I think this could be rephrased:

Once you have authenticated a user once

the duplicate once doesn't sound right!

As @JF suggests, it could be:

After you have authenticated a user once