Cards and wires

An agent on the canvas is made of cards and wires, and nothing else.

A card does one thing

Each card does one thing and says so in one line. A card has doors: what it takes in, and what it gives out. The names on the doors are plain — text, email, booking, times — and one name always means one thing, on every card.

A wire carries one thing

A wire runs from a door that gives to a door that takes, and it carries exactly what the door's name says. You can only draw a wire between doors that match: text to text, booking to booking. If a wire is not allowed, the canvas will not draw it, and it tells you why in one sentence.

The first card needs nothing

An agent starts from a card that needs nothing before it — a box a customer types in, a message arriving, a call coming in, a clock. Every other card takes something from the card before it.

The last card gives nothing

The card that shows the customer the result is the end of the line. It takes the answer and gives nothing on, and it says so.

Wires are drawn once

The same wire is never drawn twice between the same two doors. If it were, the same words would arrive twice, so the canvas refuses it.