diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a3e499..5b0e086 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+- **New Diagram…** (Explorer folder menu, *File → New File…*, Command Palette): pick Architecture, Workflow, Sequence, Data Flow, Lifecycle or Everyday Plan, enter a name, and a small valid `.archify` (YAML) file is created from a template and opened as a diagram. Title and output file follow the name.
+
 ## 0.3.0 — 2026-09-30
 
 - **`.archify` files are YAML.** They are parsed as YAML and handed to the renderer as JSON. Older JSON `.archify` files still open, since JSON is valid YAML.
diff --git a/README.md b/README.md
index 1b65cde..9eae705 100644
--- a/README.md
+++ b/README.md
@@ -8,6 +8,10 @@ This is an unofficial extension. It bundles the Archify renderer (MIT, © tt-a1i
 
 ## Quick start
 
+The fastest start: right-click a folder in the Explorer and choose **New Archify Diagram…** (also in *File → New File…* and the Command Palette). Pick a kind of diagram (Architecture, Workflow, Sequence, Data Flow, Lifecycle or Everyday Plan), give it a name, and a small working `.archify` file is created and opened. Change its YAML to fit your case.
+
+To write one by hand:
+
 1. Create a file ending in `.archify`, for example `hello.archify`:
 
    ```yaml
@@ -41,6 +45,7 @@ Archify's own JSON naming, `name.architecture.json`, `name.workflow.json` and so
 
 ## Features
 
+- **New diagram from a template**: *Archify: New Diagram…* creates a starter `.archify` file for any of the five diagram kinds, or an everyday plan, in the chosen folder.
 - **Diagram editor**: `.archify` files open as the rendered diagram. **Show Source** opens the YAML beside it, and edits re-render live.
 - **Live preview**: for Archify's `*.architecture.json`-style files, or any JSON with a `diagram_type`. Use the preview button in the editor title, <kbd>Cmd/Ctrl+K V</kbd> (to the side) or <kbd>Cmd/Ctrl+Shift+V</kbd>. The preview keeps the focus and route you selected (`#focus=…`, `#route=…`) when it re-renders.
 - **HTML viewer**: right-click a rendered `.html` file and choose **Open in Archify Viewer**, or use *Reopen Editor With… → Archify Diagram Viewer*. For Archify HTML already open as text, a button appears in the editor title. The viewer reloads when the file changes on disk.
@@ -48,7 +53,7 @@ Archify's own JSON naming, `name.architecture.json`, `name.workflow.json` and so
 - **Schema help**: completion and hover come from Archify's own schemas: built in for the JSON files, and through the YAML extension for `.archify` files.
 - **Source links**: in source-backed diagrams, clicking a source reference opens that file and line range in the editor. If the file is not in the workspace, the web link opens instead.
 - **Export**: the diagram's own Export menu (PNG, SVG, share card, …) saves through a VS Code save dialog.
-- **Commands**: *Archify: Render to HTML File…*, *Archify: Open in Browser*, *Archify: Refresh Preview*, *Archify: Show Source*.
+- **Commands**: *Archify: New Diagram…*, *Archify: Render to HTML File…*, *Archify: Open in Browser*, *Archify: Refresh Preview*, *Archify: Show Source*.
 
 ## Source evidence
 
diff --git a/package.json b/package.json
index 0043169..6a316c9 100644
--- a/package.json
+++ b/package.json
@@ -38,6 +38,12 @@
   ],
   "contributes": {
     "commands": [
+      {
+        "command": "archify.newDiagram",
+        "title": "New Diagram\u2026",
+        "category": "Archify",
+        "icon": "$(new-file)"
+      },
       {
         "command": "archify.showPreview",
         "title": "Open Preview",
@@ -145,6 +151,11 @@
         }
       ],
       "explorer/context": [
+        {
+          "command": "archify.newDiagram",
+          "when": "explorerResourceIsFolder",
+          "group": "navigation@10"
+        },
         {
           "command": "archify.showPreview",
           "when": "resourceFilename =~ /(\\.archify|\\.(architecture|workflow|sequence|dataflow|lifecycle)\\.json)$/",
@@ -167,6 +178,12 @@
           "when": "resourceFilename =~ /(\\.archify|\\.(architecture|workflow|sequence|dataflow|lifecycle)\\.json)$/",
           "group": "1_open"
         }
+      ],
+      "file/newFile": [
+        {
+          "command": "archify.newDiagram",
+          "group": "file"
+        }
       ]
     },
     "keybindings": [
diff --git a/src/extension.ts b/src/extension.ts
index 4346be3..2f55f14 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -7,6 +7,7 @@ import { HTML_VIEW_TYPE, HtmlViewerProvider } from './htmlViewer';
 import { DIAGRAM_EDITOR_VIEW_TYPE, PreviewManager } from './preview';
 import { isEvidenceError, renderDiagram, renderToFile } from './renderer';
 import { clearGitRootCache, evidenceMode, log, readText, runtimeFor } from './runtime';
+import { diagramFromTemplate, diagramName, invalidNameReason, TEMPLATES } from './templates';
 
 const JSON_LANGUAGES = new Set(['json', 'jsonc']);
 
@@ -61,6 +62,26 @@ export function activate(context: vscode.ExtensionContext): void {
   const openHtmlViewer = (uri: vscode.Uri, viewColumn?: vscode.ViewColumn) =>
     vscode.commands.executeCommand('vscode.openWith', uri, HTML_VIEW_TYPE, viewColumn);
 
+  const exists = async (uri: vscode.Uri) => {
+    try {
+      await vscode.workspace.fs.stat(uri);
+      return true;
+    } catch {
+      return false;
+    }
+  };
+
+  /** Folder for a new diagram: the clicked folder (or a file's folder), else a workspace folder. */
+  async function newDiagramFolder(arg?: unknown): Promise<vscode.Uri | undefined> {
+    if (arg instanceof vscode.Uri) {
+      const stat = await vscode.workspace.fs.stat(arg);
+      return stat.type & vscode.FileType.Directory ? arg : vscode.Uri.joinPath(arg, '..');
+    }
+    const folders = vscode.workspace.workspaceFolders ?? [];
+    if (folders.length <= 1) return folders[0]?.uri;
+    return (await vscode.window.showWorkspaceFolderPick({ placeHolder: 'Folder for the new diagram' }))?.uri;
+  }
+
   context.subscriptions.push(
     vscode.commands.registerCommand('archify.showPreview', (arg?: unknown) => {
       const uri = sourceUri(arg);
@@ -88,6 +109,44 @@ export function activate(context: vscode.ExtensionContext): void {
       if (uri) return openHtmlViewer(uri);
     }),
 
+    vscode.commands.registerCommand('archify.newDiagram', async (arg?: unknown) => {
+      const template = await vscode.window.showQuickPick(
+        TEMPLATES.map((item) => ({ label: item.label, description: item.description, template: item })),
+        { title: 'New Archify Diagram', placeHolder: 'Kind of diagram' },
+      );
+      if (!template) return;
+      const { file, defaultName } = template.template;
+
+      const folder = await newDiagramFolder(arg);
+      let target: vscode.Uri | undefined;
+      if (folder) {
+        const name = await vscode.window.showInputBox({
+          title: 'New Archify Diagram',
+          prompt: `File name in ${vscode.workspace.asRelativePath(folder, true)}`,
+          value: defaultName,
+          validateInput: async (value) =>
+            invalidNameReason(value) ??
+            ((await exists(vscode.Uri.joinPath(folder, `${diagramName(value)}.archify`))) ? `${diagramName(value)}.archify already exists.` : undefined),
+        });
+        if (name === undefined) return;
+        target = vscode.Uri.joinPath(folder, `${diagramName(name)}.archify`);
+      } else {
+        // No workspace: let the user choose where to save.
+        target = await vscode.window.showSaveDialog({
+          title: 'New Archify Diagram',
+          filters: { 'Archify Diagram': ['archify'] },
+          saveLabel: 'Create',
+        });
+        if (!target) return;
+        if (!isArchifyFile(target.path)) target = target.with({ path: `${target.path}.archify` });
+      }
+
+      const templateText = await readText(vscode.Uri.joinPath(context.extensionUri, 'templates', file));
+      const text = diagramFromTemplate(templateText, diagramBaseName(target.path));
+      await vscode.workspace.fs.writeFile(target, Buffer.from(text, 'utf8'));
+      await vscode.commands.executeCommand('vscode.openWith', target, DIAGRAM_EDITOR_VIEW_TYPE);
+    }),
+
     vscode.commands.registerCommand('archify.refreshPreview', () => previews.activePreview?.update(true)),
 
     vscode.commands.registerCommand('archify.showSource', async () => {
diff --git a/src/templates.ts b/src/templates.ts
new file mode 100644
index 0000000..79c2517
--- /dev/null
+++ b/src/templates.ts
@@ -0,0 +1,53 @@
+import { isMap, parseDocument } from 'yaml';
+import { DiagramType } from './detect';
+
+export interface DiagramTemplate {
+  /** File name under templates/. */
+  file: string;
+  type: DiagramType;
+  label: string;
+  description: string;
+  /** Suggested name for the new file, without .archify. */
+  defaultName: string;
+}
+
+export const TEMPLATES: readonly DiagramTemplate[] = [
+  { file: 'architecture.archify', type: 'architecture', label: 'Architecture', description: 'Parts of a system and how they connect', defaultName: 'architecture' },
+  { file: 'workflow.archify', type: 'workflow', label: 'Workflow', description: 'Steps of a process, in lanes', defaultName: 'workflow' },
+  { file: 'sequence.archify', type: 'sequence', label: 'Sequence', description: 'Who calls whom, in order', defaultName: 'sequence' },
+  { file: 'dataflow.archify', type: 'dataflow', label: 'Data Flow', description: 'Where data comes from and where it goes', defaultName: 'dataflow' },
+  { file: 'lifecycle.archify', type: 'lifecycle', label: 'Lifecycle', description: 'States something moves through', defaultName: 'lifecycle' },
+  { file: 'everyday-plan.archify', type: 'workflow', label: 'Everyday Plan', description: 'A plan or process from daily life', defaultName: 'plan' },
+];
+
+/** Strips a typed .archify suffix and surrounding spaces. */
+export function diagramName(input: string): string {
+  return input.trim().replace(/\.archify$/i, '').trim();
+}
+
+/** Why a name cannot be used as a file name, or undefined when it can. */
+export function invalidNameReason(input: string): string | undefined {
+  const name = diagramName(input);
+  if (!name) return 'Enter a name.';
+  if (/[\\/:*?"<>|\u0000-\u001f]/.test(name)) return 'A name cannot contain \\ / : * ? " < > | or control characters.';
+  if (/^\.+$/.test(name)) return 'Enter a name.';
+  return undefined;
+}
+
+/** "sales-report_v2" → "Sales report v2". */
+export function titleFromName(name: string): string {
+  const words = name.replace(/[-_.]+/g, ' ').replace(/\s+/g, ' ').trim();
+  return words ? words.charAt(0).toUpperCase() + words.slice(1) : name;
+}
+
+/**
+ * Template YAML with meta.title and meta.output set for the new file.
+ * Works on the YAML document so the template's comments and layout stay.
+ */
+export function diagramFromTemplate(templateText: string, name: string): string {
+  const doc = parseDocument(templateText);
+  if (!isMap(doc.get('meta'))) doc.set('meta', doc.createNode({}));
+  doc.setIn(['meta', 'title'], titleFromName(name));
+  doc.setIn(['meta', 'output'], `${name}.html`);
+  return doc.toString({ lineWidth: 0, flowCollectionPadding: false });
+}
diff --git a/templates/architecture.archify b/templates/architecture.archify
new file mode 100644
index 0000000..592a1c4
--- /dev/null
+++ b/templates/architecture.archify
@@ -0,0 +1,50 @@
+# Architecture: the parts of a system and how they connect.
+# Components need a unique id; connections link component ids.
+schema_version: 1
+diagram_type: architecture
+meta:
+  title: Web Application
+  output: architecture.html
+components:
+  - id: users
+    type: external
+    label: Users
+    sublabel: Browser
+    pos: [40, 160]
+    size: [130, 60]
+  - id: api
+    type: backend
+    label: API
+    sublabel: REST service
+    pos: [250, 160]
+    size: [130, 60]
+  - id: cache
+    type: database
+    label: Cache
+    sublabel: Redis
+    pos: [460, 60]
+    size: [130, 60]
+  - id: db
+    type: database
+    label: Database
+    sublabel: PostgreSQL
+    pos: [460, 260]
+    size: [130, 60]
+boundaries:
+  - kind: region
+    label: Production
+    wraps: [api, cache, db]
+connections:
+  - id: users-api
+    from: users
+    to: api
+    label: HTTPS
+    variant: emphasis
+  - id: api-cache
+    from: api
+    to: cache
+    label: read
+  - id: api-db
+    from: api
+    to: db
+    label: SQL
diff --git a/templates/dataflow.archify b/templates/dataflow.archify
new file mode 100644
index 0000000..d284df1
--- /dev/null
+++ b/templates/dataflow.archify
@@ -0,0 +1,55 @@
+# Data flow: where data comes from, how it is transformed, and where it ends up.
+# Nodes sit in stages (columns) and rows; flows link node ids.
+schema_version: 1
+diagram_type: dataflow
+meta:
+  title: Sales Reporting
+  output: dataflow.html
+  viewBox: [960, 420]
+stages:
+  - label: Sources
+  - label: Processing
+  - label: Storage
+  - label: Consumers
+nodes:
+  - id: shop
+    type: frontend
+    label: Web Shop
+    stage: 0
+    row: 0
+  - id: crm
+    type: external
+    label: CRM
+    stage: 0
+    row: 1
+  - id: etl
+    type: backend
+    label: Nightly ETL
+    stage: 1
+    row: 0
+  - id: warehouse
+    type: database
+    label: Warehouse
+    stage: 2
+    row: 0
+  - id: dashboard
+    type: frontend
+    label: Sales Dashboard
+    stage: 3
+    row: 0
+flows:
+  - from: shop
+    to: etl
+    label: orders
+  - from: crm
+    to: etl
+    label: customers
+    classification: PII
+    variant: security
+  - from: etl
+    to: warehouse
+    label: daily facts
+    variant: emphasis
+  - from: warehouse
+    to: dashboard
+    label: aggregates
diff --git a/templates/everyday-plan.archify b/templates/everyday-plan.archify
new file mode 100644
index 0000000..6e36a3f
--- /dev/null
+++ b/templates/everyday-plan.archify
@@ -0,0 +1,72 @@
+# Everyday plan: a workflow about daily life rather than software.
+# Node types set the colour; meta.legend renames them for the reader,
+# and icon picks the corner symbol (calendar, clock, person, briefcase, flag, moon).
+schema_version: 2
+diagram_type: workflow
+meta:
+  title: Summer Holiday Plan
+  output: everyday-plan.html
+  legend:
+    entries:
+      backend:
+        label: Time off
+      security:
+        label: Work
+      external:
+        label: Milestone
+lanes:
+  - id: plan
+    label: Plan
+  - id: work
+    label: Work
+mainPath: [today, book, holiday, back]
+nodes:
+  - id: today
+    lane: plan
+    col: 0
+    type: external
+    label: Today
+    icon: clock
+  - id: book
+    lane: plan
+    col: 1
+    type: external
+    label: Book flights
+    sublabel: by end of May
+    icon: flag
+  - id: holiday
+    lane: plan
+    col: 2
+    type: backend
+    label: Holiday
+    sublabel: 2 weeks
+    icon: calendar
+  - id: back
+    lane: plan
+    col: 3
+    type: external
+    label: Back home
+    icon: flag
+  - id: handover
+    lane: work
+    col: 1
+    type: security
+    label: Handover
+    icon: briefcase
+edges:
+  - id: plan-booking
+    from: today
+    to: book
+  - id: go
+    from: book
+    to: holiday
+    label: leave approved
+  - id: return
+    from: holiday
+    to: back
+  - id: prepare
+    from: today
+    to: handover
+    label: before leaving
+    role: branch
+    variant: security
diff --git a/templates/lifecycle.archify b/templates/lifecycle.archify
new file mode 100644
index 0000000..2c8125b
--- /dev/null
+++ b/templates/lifecycle.archify
@@ -0,0 +1,53 @@
+# Lifecycle: the states something moves through and what moves it.
+# States sit in lanes and columns; transitions link state ids.
+schema_version: 1
+diagram_type: lifecycle
+meta:
+  title: Order Status
+  output: lifecycle.html
+  viewBox: [880, 566]
+lanes:
+  - id: main
+    label: Normal path
+  - id: exits
+    label: Exits
+states:
+  - id: placed
+    type: start
+    label: Placed
+    lane: main
+    col: 0
+  - id: paid
+    type: active
+    label: Paid
+    lane: main
+    col: 1
+  - id: shipped
+    type: active
+    label: Shipped
+    lane: main
+    col: 2
+  - id: delivered
+    type: success
+    label: Delivered
+    lane: main
+    col: 3
+  - id: cancelled
+    type: failure
+    label: Cancelled
+    lane: exits
+    col: 0
+transitions:
+  - id: pay
+    from: placed
+    to: paid
+  - id: ship
+    from: paid
+    to: shipped
+  - id: deliver
+    from: shipped
+    to: delivered
+  - id: cancel
+    from: placed
+    to: cancelled
+    variant: security
diff --git a/templates/sequence.archify b/templates/sequence.archify
new file mode 100644
index 0000000..9b31010
--- /dev/null
+++ b/templates/sequence.archify
@@ -0,0 +1,50 @@
+# Sequence: who calls whom, in order. Participants are columns;
+# messages run top to bottom by y.
+schema_version: 1
+diagram_type: sequence
+meta:
+  title: Login Request
+  output: sequence.html
+  viewBox: [960, 520]
+participants:
+  - id: client
+    type: external
+    label: Client
+  - id: api
+    type: backend
+    label: API
+  - id: auth
+    type: security
+    label: Auth Service
+  - id: db
+    type: database
+    label: User Store
+messages:
+  - from: client
+    to: api
+    y: 160
+    label: POST /login
+    variant: emphasis
+  - from: api
+    to: auth
+    y: 210
+    label: verify credentials
+  - from: auth
+    to: db
+    y: 260
+    label: find user
+  - from: db
+    to: auth
+    y: 310
+    label: user record
+    variant: return
+  - from: auth
+    to: api
+    y: 360
+    label: token
+    variant: return
+  - from: api
+    to: client
+    y: 410
+    label: 200 OK + token
+    variant: return
diff --git a/templates/workflow.archify b/templates/workflow.archify
new file mode 100644
index 0000000..bd8b1a7
--- /dev/null
+++ b/templates/workflow.archify
@@ -0,0 +1,70 @@
+# Workflow: steps of a process, grouped in lanes, left to right by col.
+# mainPath lists the happy path; edges link node ids.
+schema_version: 2
+diagram_type: workflow
+meta:
+  title: Change Approval
+  output: workflow.html
+  # Rename the legend entries of the node types you use.
+  legend:
+    entries:
+      frontend:
+        label: Author step
+      security:
+        label: Review gate
+      backend:
+        label: Decision
+      external:
+        label: Outcome
+lanes:
+  - id: author
+    label: Author
+  - id: review
+    label: Reviewers
+mainPath: [draft, review, approved, released]
+nodes:
+  - id: draft
+    lane: author
+    col: 0
+    type: frontend
+    label: Draft change
+  - id: review
+    lane: review
+    col: 1
+    type: security
+    label: Review
+    sublabel: two approvals
+  - id: approved
+    lane: review
+    col: 2
+    type: backend
+    label: Approved
+  - id: released
+    lane: author
+    col: 3
+    type: external
+    label: Released
+  - id: rework
+    lane: author
+    col: 1
+    type: frontend
+    label: Rework
+edges:
+  - id: submit
+    from: draft
+    to: review
+    label: submit
+  - id: approve
+    from: review
+    to: approved
+    label: approve
+  - id: release
+    from: approved
+    to: released
+    label: release
+  - id: request-changes
+    from: review
+    to: rework
+    label: changes requested
+    role: branch
+    variant: dashed
diff --git a/test/integration/suite.ts b/test/integration/suite.ts
index 1a10ea1..2210dd2 100644
--- a/test/integration/suite.ts
+++ b/test/integration/suite.ts
@@ -97,6 +97,35 @@ export async function run(): Promise<void> {
     assert.ok(diagnostics[0].range.start.line >= 2, `reported on line ${diagnostics[0].range.start.line + 1}`);
   });
 
+  await check('New Diagram creates a .archify file from a template and opens the diagram', async () => {
+    const folder = workspaceFile('.');
+    // Stub the template pick and the name prompt; check the name validation on the way.
+    const window = vscode.window as unknown as Record<string, unknown>;
+    const originalPick = window.showQuickPick;
+    const originalInput = window.showInputBox;
+    let existingNameMessage: unknown;
+    window.showQuickPick = async (items: readonly { label: string }[]) => (await items).find((item) => item.label === 'Everyday Plan');
+    window.showInputBox = async (options: vscode.InputBoxOptions) => {
+      existingNameMessage = await options.validateInput?.('web-platform');
+      return 'summer-plan';
+    };
+    try {
+      await vscode.commands.executeCommand('archify.newDiagram', folder);
+    } finally {
+      window.showQuickPick = originalPick;
+      window.showInputBox = originalInput;
+    }
+    assert.match(String(existingNameMessage), /already exists/);
+    const uri = vscode.Uri.joinPath(folder, 'summer-plan.archify');
+    const text = new TextDecoder().decode(await vscode.workspace.fs.readFile(uri));
+    assert.match(text, /^diagram_type: workflow$/m);
+    assert.match(text, /^ {2}title: Summer plan$/m);
+    assert.match(text, /^ {2}output: summer-plan\.html$/m);
+    await waitFor('diagram editor for the new file', () =>
+      webviewTabs('archify.diagram').some((tab) => tab.input instanceof vscode.TabInputCustom && tab.input.uri.toString() === uri.toString()),
+    );
+  });
+
   await check('opens a live preview beside the source', async () => {
     await vscode.commands.executeCommand('archify.showPreviewToSide', workspaceFile('production-deployment.architecture.json'));
     const tabs = await waitFor('preview tab', () => {
diff --git a/test/templates.test.ts b/test/templates.test.ts
new file mode 100644
index 0000000..1139abf
--- /dev/null
+++ b/test/templates.test.ts
@@ -0,0 +1,64 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { test } from 'node:test';
+import { parse } from 'yaml';
+import { readDiagramSource } from '../src/detect';
+import { validate } from '../src/renderer';
+import { diagramFromTemplate, diagramName, invalidNameReason, TEMPLATES, titleFromName } from '../src/templates';
+
+const root = path.resolve(__dirname, '..', '..');
+const templates = path.join(root, 'templates');
+const runtime = {
+  cliPath: path.join(root, 'vendor', 'archify', 'bin', 'archify.mjs'),
+  nodePath: process.execPath,
+  runAsNode: false,
+  workDir: fs.mkdtempSync(path.join(os.tmpdir(), 'archify-ext-test-')),
+};
+
+test('every template file is listed and every listed template exists', () => {
+  const files = fs.readdirSync(templates).filter((file) => file.endsWith('.archify')).sort();
+  assert.deepEqual(TEMPLATES.map((item) => item.file).sort(), files);
+});
+
+for (const item of TEMPLATES) {
+  test(`template ${item.file} is a valid ${item.type} diagram`, async () => {
+    const text = diagramFromTemplate(fs.readFileSync(path.join(templates, item.file), 'utf8'), item.defaultName);
+    const source = readDiagramSource(text, `${item.defaultName}.archify`);
+    assert.ok(source);
+    assert.equal(source.type, item.type);
+    assert.equal(source.format, 'yaml');
+    const result = await validate(runtime, source.type, source.json);
+    assert.deepEqual(
+      result.diagnostics.filter((d) => d.severity === 'error').map((d) => `${d.code}: ${d.message}`),
+      [],
+    );
+    assert.ok(result.ok);
+  });
+}
+
+test('diagramFromTemplate sets title and output and keeps comments and flow lists', () => {
+  const text = diagramFromTemplate('# keep me\nschema_version: 1\nmeta:\n  title: Old\n  output: old.html\npos: [1, 2]\n', 'sales-report');
+  assert.match(text, /^# keep me/);
+  assert.match(text, /pos: \[1, 2\]/);
+  assert.deepEqual(parse(text).meta, { title: 'Sales report', output: 'sales-report.html' });
+});
+
+test('diagramFromTemplate adds meta when the template has none', () => {
+  assert.deepEqual(parse(diagramFromTemplate('diagram_type: workflow\n', 'plan')).meta, { title: 'Plan', output: 'plan.html' });
+});
+
+test('diagram names', () => {
+  assert.equal(diagramName('  web.archify '), 'web');
+  assert.equal(diagramName('web.ARCHIFY'), 'web');
+  assert.equal(invalidNameReason('web'), undefined);
+  assert.equal(invalidNameReason('my plan 2026'), undefined);
+  assert.ok(invalidNameReason(''));
+  assert.ok(invalidNameReason('.archify'));
+  assert.ok(invalidNameReason('..'));
+  assert.ok(invalidNameReason('a/b'));
+  assert.ok(invalidNameReason('a:b'));
+  assert.equal(titleFromName('sales-report_v2'), 'Sales report v2');
+  assert.equal(titleFromName('plan'), 'Plan');
+});