People are crayon. Pipes are pen.

Part V draws ideas. This part draws systems: pipelines, models, databases, messages, EDI. A four-year-old cannot draw a pipeline, so the appliances draw it. We asked what a roomba would draw with. Not crayon; it has no hands. It has a pen that moves in straight lines, a grid it has mapped, and a memory that is a list.

The roomba’s hand

I.Graph paper. Machine drawings sit on a dot grid, 8 units. Everything snaps to it. Crayon drawings sit on plain paper; the paper tells you which hand drew it before you read a word.
II.One pen, no shake. 1.5 units of ink, square corners, no wobble filter. The machine’s line is steady because the machine is not four.
III.Right angles only. Pipes run horizontal or vertical and bend at 90°. No diagonals, no curves. A roomba does not do curves.
IV.Solid carries, dashed bounds. A solid line is data moving. A dashed line is a boundary: a seam, a tenant, a trust edge. Dotted lines belong to the crayon and never appear here.
V.Typewriter labels. Names are the exact identifiers from the tree, in Computer Modern Typewriter: valueCents, tenantPrisma(). Numbers carry units. Nothing is paraphrased.
VI.Grey is the machine’s colour. Nodes fill with the appliance grey at low strength. Red, dashed, means a gap: unbuilt, missing, or the weaker base. It is the only other colour.
VII.People are crayon. Wherever a person touches the plumbing, they appear as a crayon blob with a handwritten name, wobble and all. The two hands meet at exactly that edge and nowhere else.
VIII.The claim is still type. One sentence under the drawing, grown-up voice. The mark is still last.

The roomba’s atoms

i.Node

A process. Rectangle, grey fill, identifier inside.

ii.Store

A table or file. A node with a second line at the top: a ledger has a header.

iii.Pipe

Data moving. Solid, right angles, a small filled head where it arrives.

iv.Seam

A boundary. Dashed, labelled at the top-left corner with what it bounds.

v.Measure

A number with its unit, under the name, lighter. Never rounded for effect.

vi.Gap

Unbuilt or missing. Red dashed, with the evidence as its measure.

vii.Person

Crayon, on the grid, wobbling. The one thing the roomba did not draw.

viii.Fit

How much crosses a pipe unchanged, as a measure on the pipe. 1.0 composes as-is.

ix.Claim

Unchanged from Part V. Type, one sentence, the only place a fact lives.

Three drawings from the tree

The Room v0.1 · probe/BUILDS.md §1

Every record the Room keeps is a bare hash today; one sign/verify module turns all of them into custody.

Money · probe/BUILDS.md, ranked 4

Money is centavos as a bigint with a currency; the adapter sits at the old Katura models, and the refactor’s float layer is not a base for anything canonical.

The crawl · crawl/CRAWL.md

The crawl reads the tree and writes a cache; the probe fills in c; nothing in the pipeline calls a model or the network.

Gloss

ix · a word that opens the documentation

A dashed grey underline is a door. Rest on it and the machine opens a card from the internal documentation: first its skeleton, then the grown-up definition with the file it came from. Inside every gloss is the crayon button; the four voice explains the definition, not the page.

I.Dashed grey, 1.5 units, is a gloss. Red is a conviction. Ink is a link. A word is never two of these.
II.Hover opens; nothing slides. The card is on graph paper: the machine drew it. The skeleton shows first because the machine does not pretend to be instant.
III.Definitions are grown-up voice, at most four sentences, with the exact path in typewriter. Numbers are the tree’s numbers.
IV.The card stays until you click elsewhere or open another. It never covers the word it explains.
V.A gloss explains; a link goes. Never both on one word.

The Room · what the tree says

The Room is one tenant per lawyer. At the door, the contract toggle moves the call from anon to consult to notary, and each move is signed. Whatever is said in notary becomes a custody entry: a hash of the content, signed with Ed25519 by a published issuer key, written to an append-only ledger. Today every one of those records is a bare hash. The media path is another matter: without E2EE the aura is theatre, so the terms say transport-encrypted. Where the Room meets Rosser’s trees is a seam; how much crosses it unchanged is c_k. Money crossing it becomes Money, and the deal that outlives the call becomes a Deal Room.

Nine parts, no more

Part IV gains the Gloss. Part V gains the roomba’s hand for anything with a pipe in it. Sources: README.md, crawl/CRAWL.md, probe/BUILDS.md of the monorepo, 4 Sep 2026. VII. The arms →