Since spying was not part of the original game, I (we) plan to add this as an orthogonal feature with limited effect on diplomacy (e.g., if spies get captured and killed, the relation points will decrease somewhat).
The design and attributes are not final yet, nor are the mechanics behind mission successes and capture-turn logic.
The spy screen will be assigned to F11 (the trading will be assigned to F12). I haven't decided about the new Achievements/Statistics screen keys.
I've picked the Church and Mechanical dev center images and combined them into the new Spy Center. For now, all races use the same building.
Each spy center provides one slot for a spy. You can only build one per planet.
The spying screen has two main views: your spies and captured spies. We might use the IG2's standing figures or use a cropped version of the diplomacy pictures of IG1's races. In the latter case, the layout might change a bit.
(Some assignments will show different controls.)
The second view is for the captured spies which uses most of the infrastructure.