XML files are in the \Steam\steamapps\common\Endless Space 2\Public\Quests folder

There is a fan Wikia but there's not much there yet. And as for the official Wiki... have you noticed the scrolling text at the bottom of the main menu screen? Click it and you get this:

"Welcome to the official wiki for Endless Space 2, a 4X turn-based sci-fi  strategy game in the Endless universe by Amplitude Studios. An Early  Access version of the game is currently available on Steam – The  official release date is the 19th march 2017!"

May be time for some updating :D

Downer wrote:

XML files are in the \Steam\steamapps\common\Endless Space 2\Public\Quests folder

yes i found those xml files, but could´t find the rewars for each quest branchs.  

somebody post this on reddit:

\Endless Space 2\Public\Quests

Shows how the quests work, but not very readable.

\Endless Space 2\Public\Localization\english\ES2_Localization_Quest_Locales.xml

Shows all the Faction Quest descriptions, allowing you to know/guess what the choices for each Chapter (1-4) are.

\Endless Space 2\Public\Localization\english\ES2_Localization_Assets_Locales.xml

Includes most rewards from Faction Quests

i will look into it later