Trading Post
A fair price is whatever both sides of the river agree on.
Trades goods with another player. It’s built across the border between your district and theirs, in pairs like a District Crossing.
A deal says what each side gives: “10 logs for 4 planks”, say. Each side’s owner edits their half, and the deal only runs once both have approved it. Changing it asks the other side to approve again. An approved deal trades whenever both halves have the goods and room for what they get.
A post holds up to 10 deals, each half stores 50 of each good, and its workers keep two trades’ worth ready. Pending deals raise a “Trade deal to approve” alert, and the Trades tab of the settlement panel lists every deal you’re part of.