@@ -0,0 +1,5 @@
+---
+"@sketchi/cli": patch
+---
+
+ER diagrams give every relationship its own end where several lines meet one column. A table row can hold two line ends on a side with their bars or crow's feet apart; a third used to squeeze in between, so the marks ran together into one stroke and the reader could not tell which end belonged to which line. In a SaaS workspace schema, three relationships into `organizations.id` from the left merged that way. Now a row that holds more than two ends on a side grows taller, so each end has a port of its own on that row and the line still lands on the column it references. A one-row table with two ends on a side also makes room below them, clear of its corner. Lines that loop back to a table in the same column now take the port nearest the turn, which also removes the crossing the SaaS schema drew there. A table only grows when the drawing reads no worse: no more crossings, reader findings, detours or marks on labels, and no larger drawing.
@@ -5,7 +5,7 @@ import { validateExcalidrawScene } from "@sketchi/diagram-excalidraw";
 import type { RenderedDiagramScene } from "@sketchi/diagram-renderer";
 
 import { CodeModeArtifactStorage, makeMemoryArtifactStorage } from "./artifacts.js";
-import { BuildErDiagramResultSchema } from "./contract.js";
+import { BuildErDiagramResultSchema, RenderedDiagramSceneSchema } from "./contract.js";
 import { canonicalDocumentFromDiagram } from "./documents.js";
 import { applyDiagramPatch, buildErDiagram, CodeModeRuntimeEnvironment } from "./runtime.js";
 
@@ -93,6 +93,39 @@ describe("Code Mode native ER diagram", () => {
 		]);
 	});
 
+	it("builds a key row five tables reference into valid artifacts, its row a text per cell", async () => {
+		const children = ["projects", "labels", "api_keys", "memberships", "subscriptions"];
+		const built = await build({
+			title: "Workspace",
+			entities: [
+				{ id: "organizations", fields: ["id uuid PK", "name text"] },
+				...children.map((id) => ({ id, fields: ["id uuid PK", "organization_id uuid FK"] })),
+			],
+			relationships: children.map((id) => ({
+				from: `${id}.organization_id`,
+				to: "organizations.id",
+				fromCardinality: "zero-or-many",
+				toCardinality: "one",
+			})),
+		});
+		if (!built.ok) throw new Error(JSON.stringify(built.issues));
+		const formats = new Map(built.artifact.formats.map((format) => [format.format, format.inline]));
+		// The scene decodes as the CLI and MCP read it: no empty text where a row has no key or type.
+		const scene = Schema.decodeUnknownSync(RenderedDiagramSceneSchema)(formats.get("scene"));
+		const cells = scene.elements.flatMap((element) =>
+			element.type === "text" && element.id.startsWith("text:organizations:") ? [element.id] : [],
+		);
+		expect(cells.sort()).toEqual([
+			"text:organizations:fields:0",
+			"text:organizations:fields:1",
+			"text:organizations:keys:0",
+			"text:organizations:types:0",
+			"text:organizations:types:1",
+		]);
+		const excalidraw = formats.get("excalidraw") as Parameters<typeof validateExcalidrawScene>[0];
+		expect(validateExcalidrawScene(excalidraw)).toEqual({ ok: true, issues: [] });
+	});
+
 	it("reads cardinality aliases, source/target and a combined cardinality", async () => {
 		const built = await build({
 			...shopSpec,
 
@@ -185,9 +185,9 @@ function routingCounts(scene: RenderedDiagramScene) {
 /**
  * Ends whose bar or foot another line runs through, other than a neighbor's
  * on the same row of the same table: Excalidraw draws each head min(20, run / 2)
- * long and 20 sin 25° either side of its line. A row holding more ends than
- * its band spaces a mark apart may bunch them, but no line from another row,
- * or passing by, may cross a mark.
+ * long and 20 sin 25° either side of its line. A row whose growth would draw
+ * worse may still bunch its ends, but no line from another row, or passing by,
+ * may cross a mark.
  */
 function foreignMarks(scene: RenderedDiagramScene): string[] {
 	const arrows = scene.elements.flatMap((element) => (element.type === "arrow" ? [element] : []));
@@ -251,6 +251,29 @@ function foreignMarks(scene: RenderedDiagramScene): string[] {
 	);
 }
 
+/**
+ * Neighboring ends on one side of a table whose heads run together: Excalidraw
+ * draws a bar or foot 17 across, so two ports nearer than 20 read as one end.
+ */
+function bunchedEnds(scene: RenderedDiagramScene): number {
+	const sides = new Map<string, number[]>();
+	for (const arrow of scene.elements)
+		if (arrow.type === "arrow")
+			for (const [node, point] of [
+				[arrow.sourceNodeId, arrow.points[0]],
+				[arrow.targetNodeId, arrow.points.at(-1)!],
+			] as const) {
+				const key = `${node}:${Math.round(point.x)}`;
+				sides.set(key, [...(sides.get(key) ?? []), point.y]);
+			}
+	let bunched = 0;
+	for (const ports of sides.values()) {
+		ports.sort((a, b) => a - b);
+		bunched += ports.slice(1).filter((port, index) => port - ports[index]! < 20).length;
+	}
+	return bunched;
+}
+
 /** Everything the export validator, the canvas validator or the layout guards would flag. */
 function defects(diagram: ErDiagram): string[] {
 	const scene = renderDiagram(diagram);
@@ -310,6 +333,12 @@ function defects(diagram: ErDiagram): string[] {
  * together they may draw no more of either.
  */
 const ER_ROUTING = "1/2 0/0 0/0 0/0 0/0 1/0 0/0 0/1 0/0 0/0 0/0 1/0 0/0 0/0 0/0 0/0";
+/**
+ * Neighboring ends that bunch across the schemas checked: a row holding more
+ * than two ends on a side grows to give each a port of its own, except where
+ * growing would draw worse (99 and 3 before rows grew).
+ */
+const ER_BUNCHED = { ci: 0, full: 18 };
 
 /** Schemas checked in CI; the full fuzz runs locally with ER_FUZZ=full (and any ER_FUZZ_SEED). */
 const CI_SCHEMAS = 16;
@@ -348,4 +377,10 @@ describe("ER routing fuzz", () => {
 		expect(total(drawn, 0)).toBeLessThanOrEqual(total(pinned, 0));
 		expect(total(drawn, 1)).toBeLessThanOrEqual(total(pinned, 1));
 	});
+
+	it("bunches no more ends than pinned, each crowded row grown for its ends", () => {
+		const bunched = schemas.reduce((sum, schema) => sum + bunchedEnds(renderDiagram(schema)), 0);
+		if (process.env["PRINT_ROUTING"]) console.log("PIN er bunched", bunched);
+		expect(bunched).toBeLessThanOrEqual(FULL ? ER_BUNCHED.full : ER_BUNCHED.ci);
+	});
 });
@@ -7,6 +7,7 @@ import {
 	getCanvasValidationIssues,
 	orgChartEr,
 	parseErDiagram,
+	parseErFieldShorthand,
 	segmentCrossesBoundsInterior,
 	segmentsFromPoints,
 } from "@sketchi/diagram-core";
@@ -171,6 +172,96 @@ function foreignMarks(scene: RenderedDiagramScene): string[] {
 const aspectOf = (scene: RenderedDiagramScene) =>
 	Math.max(scene.width / scene.height, scene.height / scene.width);
 
+/**
+ * Each field row's middle and height from its table's top, read off the drawn
+ * field names: one text per column holds every row 28 apart, or, where a row
+ * grows, one text per row stands at that row's middle.
+ */
+function drawnRows(
+	scene: RenderedDiagramScene,
+	id: string,
+): readonly { readonly middle: number; readonly height: number }[] {
+	const box = table(scene, id);
+	const column = text(scene, `text:${id}:fields`);
+	if (column?.type === "text")
+		return column.text
+			.split("\n")
+			.map((_, row) => ({ middle: rowY(box, row) - box.y, height: 28 }));
+	const middles: number[] = [];
+	for (let row = 0; ; row += 1) {
+		const cell = text(scene, `text:${id}:fields:${row}`);
+		if (cell?.type !== "text") break;
+		middles.push(cell.y - box.y);
+	}
+	let top = 46;
+	return middles.map((middle) => {
+		const height = 2 * (middle - top);
+		top += height;
+		return { middle, height };
+	});
+}
+
+/** Sonnet's saas-workspace-er s5 in round 24, as the model wrote it: five lines end on organizations.id. */
+const saasWorkspaceS5 = parseErDiagram({
+	id: "saas-workspace-database",
+	title: "SaaS Workspace Database",
+	type: "er",
+	entities: (
+		[
+			["organizations", ["id uuid PK", "name text"]],
+			["users", ["id uuid PK", "email text UK", "name text"]],
+			["memberships", ["organization_id uuid PK FK", "user_id uuid PK FK", "role text"]],
+			["projects", ["id uuid PK", "organization_id uuid FK", "name text"]],
+			[
+				"tasks",
+				["id uuid PK", "project_id uuid FK", "assignee_id uuid? FK", "title text", "due_on date?"],
+			],
+			["comments", ["id uuid PK", "task_id uuid FK", "author_id uuid FK", "body text"]],
+			["labels", ["id uuid PK", "organization_id uuid FK", "name text"]],
+			["task_labels", ["task_id uuid PK FK", "label_id uuid PK FK"]],
+			["plans", ["id uuid PK", "name text UK", "monthly_price numeric"]],
+			[
+				"subscriptions",
+				["id uuid PK", "organization_id uuid FK UK", "plan_id uuid FK", "renews_on date"],
+			],
+			[
+				"invoices",
+				["id uuid PK", "subscription_id uuid FK", "amount numeric", "paid_at timestamptz?"],
+			],
+			[
+				"api_keys",
+				["id uuid PK", "organization_id uuid FK", "created_by uuid FK", "token_hash text UK"],
+			],
+		] as const
+	).map(([id, fields]) => ({ id, fields: fields.map(parseErFieldShorthand) })),
+	relationships: (
+		[
+			["memberships.organization_id", "organizations.id", "one-or-many", "one"],
+			["memberships.user_id", "users.id", "zero-or-many", "one"],
+			["projects.organization_id", "organizations.id", "zero-or-many", "one"],
+			["labels.organization_id", "organizations.id", "zero-or-many", "one"],
+			["api_keys.organization_id", "organizations.id", "zero-or-many", "one"],
+			["tasks.project_id", "projects.id", "zero-or-many", "one"],
+			["tasks.assignee_id", "users.id", "zero-or-many", "zero-or-one"],
+			["comments.task_id", "tasks.id", "zero-or-many", "one"],
+			["comments.author_id", "users.id", "zero-or-many", "one"],
+			["task_labels.task_id", "tasks.id", "zero-or-many", "one"],
+			["task_labels.label_id", "labels.id", "zero-or-many", "one"],
+			["subscriptions.organization_id", "organizations.id", "zero-or-one", "one"],
+			["subscriptions.plan_id", "plans.id", "zero-or-many", "one"],
+			["invoices.subscription_id", "subscriptions.id", "zero-or-many", "one"],
+			["api_keys.created_by", "users.id", "zero-or-many", "one"],
+		] as const
+	).map(([from, to, fromCardinality, toCardinality], index) => ({
+		id: `relationship-${index + 1}`,
+		from,
+		to,
+		fromCardinality,
+		toCardinality,
+	})),
+	style: { accentColor: "#8f707f", backgroundColor: "#fffdf8" },
+});
+
 describe("ER renderer", () => {
 	it("renders every fixture into a valid deterministic scene", () => {
 		for (const diagram of [erFixture, orgChartEr, ...Object.values(erStressFixtures)]) {
@@ -454,14 +545,82 @@ describe("ER renderer", () => {
 		}
 	});
 
-	it("places a workspace's two hubs so its lines cross once at most, apart at their ends", () => {
+	it("places a workspace's two hubs so no lines cross, apart at their ends", () => {
 		const scene = renderDiagram(erStressFixtures.saasWorkspace);
 		// The organization holds five ends on its id row and users four: spread
-		// over both sides, two to a side stand clear and only a third bunches.
-		expect(crossings(arrows(scene))).toBeLessThanOrEqual(1);
-		expect(bunchedEnds(scene)).toBeLessThanOrEqual(2);
+		// over both sides, two to a side stand clear, and the row holding a third
+		// grows to give it a port of its own.
+		expect(crossings(arrows(scene))).toBe(0);
+		expect(bunchedEnds(scene)).toBe(0);
+		expect(wraps(scene)).toBe(0);
+		expect(aspectOf(scene)).toBeLessThanOrEqual(2);
+	});
+
+	it("gives each of five lines on one key its own end, on that key's row", () => {
+		const scene = renderDiagram(saasWorkspaceS5);
+		// Two ends to a side stand clear in a row's band; the third on a side has
+		// its row grow, so no two bars or feet run together.
+		expect(bunchedEnds(scene)).toBe(0);
+		const organizations = table(scene, "organizations");
+		const ends = arrows(scene).flatMap((line) =>
+			[
+				[line.sourceNodeId, line.points[0]],
+				[line.targetNodeId, line.points.at(-1)!],
+			].flatMap(([node, point]) => (node === "organizations" ? [point as { y: number }] : [])),
+		);
+		expect(ends).toHaveLength(5);
+		// Each still meets the id row, inside its band, and reads as id's: no
+		// further from id's middle than two thirds of its way to name's, as
+		// either of two ends on a plain row.
+		const [id, name] = drawnRows(scene, "organizations");
+		for (const end of ends) {
+			const y = end.y - organizations.y;
+			expect(Math.abs(y - id!.middle)).toBeLessThanOrEqual(id!.height / 2 - 3);
+			expect(Math.abs(y - id!.middle)).toBeLessThanOrEqual((2 / 3) * Math.abs(y - name!.middle));
+		}
+		// labels' row lines up with the port its line takes on the grown row, so it runs straight.
+		expect(arrow(scene, "relationship-4").points).toHaveLength(2);
+		expect(foreignMarks(scene)).toEqual([]);
+		// Its loop from api_keys takes the upper port, inside the line from
+		// projects, so the two no longer cross.
+		expect(crossings(arrows(scene))).toBe(0);
 		expect(wraps(scene)).toBe(0);
 		expect(aspectOf(scene)).toBeLessThanOrEqual(2);
+		expect(getCanvasValidationIssues(scene)).toEqual([]);
+	});
+
+	it("keeps two ends on a one-row table's side a port step apart, clear of its corner", () => {
+		const diagram = parseErDiagram({
+			id: "single-row",
+			title: "Single row",
+			type: "er",
+			entities: [
+				{ id: "accounts", fields: [{ name: "id", type: "int", pk: true }] },
+				...["orders", "invoices"].map((id) => ({
+					id,
+					fields: [
+						{ name: "id", type: "int", pk: true },
+						{ name: "account_id", type: "int", fk: true },
+					],
+				})),
+			],
+			relationships: ["orders", "invoices"].map((id) => ({
+				id,
+				from: "accounts.id",
+				to: `${id}.account_id`,
+				fromCardinality: "one" as const,
+				toCardinality: "zero-or-many" as const,
+			})),
+		});
+		const scene = renderDiagram(diagram);
+		const accounts = table(scene, "accounts");
+		const starts = arrows(scene)
+			.map((line) => line.points[0].y)
+			.sort((a, b) => a - b);
+		expect(starts).toHaveLength(2);
+		expect(starts[1]! - starts[0]!).toBeGreaterThanOrEqual(20);
+		expect(accounts.y + accounts.height - starts[1]!).toBeGreaterThanOrEqual(16);
+		expect(bunchedEnds(scene)).toBe(0);
 	});
 
 	it("keeps a small schema within two to one, stacking tables where a row runs wide", () => {
-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +"@sketchi/cli": patch
 +---
++
 +ER diagrams give every relationship its own end where several lines meet one column. A table row can hold two line ends on a side with their bars or crow's feet apart; a third used to squeeze in between, so the marks ran together into one stroke and the reader could not tell which end belonged to which line. In a SaaS workspace schema, three relationships into `organizations.id` from the left merged that way. Now a row that holds more than two ends on a side grows taller, so each end has a port of its own on that row and the line still lands on the column it references. A one-row table with two ends on a side also makes room below them, clear of its corner. Lines that loop back to a table in the same column now take the port nearest the turn, which also removes the crossing the SaaS schema drew there. A table only grows when the drawing reads no worse: no more crossings, reader findings, detours or marks on labels, and no larger drawing.