Canvases
The agent sketches, you correct the sketch, the prototype proves it.
Your planning agent can draw. Ask it for a flow and you get an editable canvas in the conversation, not a picture: move a box, delete an arrow, add a lane. Drawings live alongside your Specs, and they ride along when you push a plan to your issue tracker.
Two kinds of drawing
A diagram is a flow or an architecture: boxes, decisions and arrows. Ask for one when the shape of the work is easier to agree on drawn than described, especially before any Specs are written.
A wireframe is the structure of a screen a Spec describes: which regions exist, what sits in them, what the reader can press.
Both are deliberately rough. There is no way to set a colour, a typeface or spacing: not for the agent, and not for you. That is the point: a sketch is free to produce and free to throw away, and your prototype is where fidelity belongs. A drawing that started competing with the prototype would be two answers to the same question, and the prototype is the one people click.
Editing what the agent drew
Everything the agent draws is yours to change. Drag a box, retype a label, delete something that does not belong. Your edits save as you make them.
Nothing is lost when you edit: the drawing you leave behind is the one that stays. Tell the agent what you changed and why, and it will follow. Reading a canvas back automatically is not something it does yet.
Putting a canvas in a Spec
Add to Spec on a drawing in the conversation puts it into that Spec's document.
Once it is there it is an ordinary block. Drag it above the acceptance criteria, or below the goal, or wherever it makes the Spec read best. Delete it like any other block. Add as many as the Spec needs. There is no limit and no fixed slot, because a drawing that can only live at the top is a drawing in the wrong place half the time.
Drawing your own
Type /Canvas in a Spec or a context document to insert one and sketch it yourself.
You will notice there is no equivalent for wireframes. That is deliberate. Hand-drawing fake screens is work we would rather nobody did. When a wireframe is worth having, the agent can produce one from the Spec in seconds, and you correct it from there.
What your issue tracker gets
When you push a plan, each canvas in a Spec becomes a link to that canvas, in the same place you put the block. Open the link and you are in the drawing, able to edit it.
It is a link rather than an embedded picture because a canvas is yours: viewing one takes your Plansmith sign-in, and an embedded image would show as broken to anyone reading the issue who is not signed in. Sending the drawing itself to your issue tracker as an attachment is work we have not finished yet.