Add meaningful product usage analytics

docs/README.md

@@ -26,5 +26,6 @@ The repository root retains the canonical [`LICENSE`](../LICENSE) and [`NOTICE`]
 
 ## Development references
 
+- [Product usage analytics](product-analytics.md)
 - [Vercel agent notes](development/VERCEL_AGENTS.md)
 - [Pose diagnostics summary](diagnostics/pose-summary.json)

docs/product-analytics.md

@@ -0,0 +1,71 @@
+# Product usage analytics
+
+Posecode keeps Vercel pageviews and product-usage events separate. Pageviews
+answer “which routes were visited?”; the events below answer “did someone use
+the product?”
+
+## Provider and production configuration
+
+The implementation is provider-neutral at the call sites. Event names, payload
+types, failure isolation, and session deduplication live in
+`playground/src/analytics.ts`. The current adapter is
+`playground/src/vercel-analytics.ts`.
+
+Vercel Web Analytics pageviews remain enabled without extra configuration.
+Vercel's current plan table says custom events are **not available on Hobby**;
+they are available on Pro and Enterprise. Pro allows at most two properties per
+custom event. The schema below deliberately stays within that limit.
+
+To enable product events on a Vercel Pro or Enterprise production project:
+
+1. Enable Web Analytics for the project in Vercel.
+2. Set `VITE_PRODUCT_ANALYTICS_PROVIDER=vercel` for the Production environment.
+3. Redeploy so Vite includes the provider choice in the client bundle.
+4. Exercise one event and confirm it in **Project → Analytics → Events**.
+
+Do not set the variable on Hobby expecting dashboard data: Hobby continues to
+show pageviews but does not expose custom events. No alternate paid analytics
+vendor is installed. A future adapter can call `configureUsageAnalytics`
+without changing UI event call sites.
+
+Sources:
+
+- [Vercel custom events](https://vercel.com/docs/analytics/custom-events)
+- [Vercel Web Analytics limits and pricing](https://vercel.com/docs/analytics/limits-and-pricing)
+
+## Event dictionary
+
+| Event | Fires when | Properties |
+|---|---|---|
+| `preset_opened` | A bundled movement is actually opened at initial load or selected in the library. | `source`: `library`, `direct_url`, `shared_link`, or `landing_cta`; `preset_id`: bundled stable ID |
+| `editor_changed` | The first real CodeMirror user edit in the page session. Programmatic preset loads do not count. | `document_kind`: `preset`, `shared`, or `custom` |
+| `render_succeeded` | `viewer.load()` successfully accepts a new meaningful document revision. Lazy boot and repeated recompiles of the same revision are deduplicated. The animation frame loop never emits this event. | `trigger`: `initial`, `preset_open`, `shared_link`, or `editor_change`; `document_kind` |
+| `share_created` | The generated preset/encoded URL has successfully been written to the clipboard. | `share_kind`: `preset` or `encoded` |
+| `embed_docs_clicked` | The embed documentation CTA on `/for-products` is clicked. | `location`: `for_products` |
+| `install_command_copied` | An npm/npx command on `/for-products` is successfully written to the clipboard. | `command`: `embed`, `packages`, or `mcp`; `location`: `for_products` |
+
+## Reading the dashboard
+
+Open **Analytics → Events**, select an event, then drill into its properties.
+Useful readings include:
+
+- `preset_opened` grouped by `source` separates library discovery from direct,
+  shared, and landing-page entry.
+- Compare `editor_changed` and `render_succeeded` counts to see whether editing
+  reaches a valid renderer update. They are intentionally not a strict funnel:
+  initial and preset renders also count.
+- `share_created` is a confirmed clipboard outcome, not a button-click count.
+- Group `install_command_copied` by `command` to compare integration intent.
+
+Vercel reports aggregate events rather than a user-level funnel. Do not attempt
+to join individual visitors or reconstruct sessions from these payloads.
+
+## Privacy and resilience
+
+Events never contain Posecode source text, authoring prompts, personal data,
+full share tokens, query strings, referrers, or sensitive URLs. `preset_id` is a
+bounded public catalogue identifier; all other values are closed enums.
+
+Every analytics call is best-effort and catches provider failures. Ad blockers,
+network failures, a missing provider configuration, or plan limitations do not
+change editing, rendering, sharing, navigation, or clipboard behavior.

playground/for-products.html

@@ -77,18 +77,28 @@ <h3>Drop in a movement player</h3>
             <p>Use the framework-free <code>&lt;posecode-player&gt;</code> web component with inline Posecode, a <code>.posecode</code> URL, or a share token.</p>
             <pre aria-label="HTML web component example"><code>&lt;script src="https://unpkg.com/posecode-embed@0.2.2/dist/posecode-embed.js"&gt;&lt;/script&gt;
 &lt;posecode-player src="/moves/squat.posecode"&gt;&lt;/posecode-player&gt;</code></pre>
+            <div class="integration-actions">
+              <button class="code-action" type="button" data-copy-command="embed" data-command="npm install posecode-embed">Copy npm command</button>
+              <a class="docs-action" data-embed-docs href="https://github.com/posecode-dev/posecode/tree/main/packages/posecode-embed#readme" target="_blank" rel="noopener">Read embed docs&nbsp;→</a>
+            </div>
           </article>
           <article class="integration-card reveal">
             <span class="card-index">02 / compose</span>
             <h3>Own the interface</h3>
             <p>Parse text into a typed, range-of-motion-clamped IR, then drive the Three.js renderer inside your own editor, lesson, or workflow.</p>
             <pre aria-label="npm installation example"><code>npm install posecode-parser posecode-render three</code></pre>
+            <div class="integration-actions">
+              <button class="code-action" type="button" data-copy-command="packages" data-command="npm install posecode-parser posecode-render three">Copy npm command</button>
+            </div>
           </article>
           <article class="integration-card reveal">
             <span class="card-index">03 / agents</span>
             <h3>Run movement tools locally</h3>
             <p>The npm MCP server runs over stdio on your machine. It teaches an MCP client the language, validates documents, and creates playground links.</p>
             <pre aria-label="Local MCP command example"><code>npx -y posecode-mcp@latest</code></pre>
+            <div class="integration-actions">
+              <button class="code-action" type="button" data-copy-command="mcp" data-command="npx -y posecode-mcp@latest">Copy run command</button>
+            </div>
           </article>
         </div>
       </section>

playground/src/analytics.ts

@@ -0,0 +1,94 @@
+/**
+ * Provider-neutral product usage analytics.
+ *
+ * Event payloads intentionally contain only low-cardinality product metadata.
+ * Never add Posecode source, share tokens, prompts, or URLs here.
+ */
+
+export const USAGE_EVENT_NAMES = {
+  presetOpened: "preset_opened",
+  editorChanged: "editor_changed",
+  renderSucceeded: "render_succeeded",
+  shareCreated: "share_created",
+  embedDocsClicked: "embed_docs_clicked",
+  installCommandCopied: "install_command_copied",
+} as const;
+
+export type PresetOpenSource =
+  | "library"
+  | "direct_url"
+  | "shared_link"
+  | "landing_cta";
+export type DocumentKind = "preset" | "shared" | "custom";
+export type RenderTrigger =
+  | "initial"
+  | "preset_open"
+  | "shared_link"
+  | "editor_change";
+export type ShareKind = "preset" | "encoded";
+export type InstallCommand = "embed" | "packages" | "mcp";
+
+export interface UsageEventMap {
+  preset_opened: { source: PresetOpenSource; preset_id: string };
+  editor_changed: { document_kind: DocumentKind };
+  render_succeeded: { trigger: RenderTrigger; document_kind: DocumentKind };
+  share_created: { share_kind: ShareKind };
+  embed_docs_clicked: { location: "for_products" };
+  install_command_copied: {
+    command: InstallCommand;
+    location: "for_products";
+  };
+}
+
+export type UsageEventName = keyof UsageEventMap;
+export type UsageEventSink = <Name extends UsageEventName>(
+  name: Name,
+  properties: UsageEventMap[Name],
+) => void;
+
+let sink: UsageEventSink | null = null;
+
+export function configureUsageAnalytics(nextSink: UsageEventSink | null): void {
+  sink = nextSink;
+}
+
+export function trackUsageEvent<Name extends UsageEventName>(
+  name: Name,
+  properties: UsageEventMap[Name],
+): void {
+  try {
+    sink?.(name, properties);
+  } catch {
+    // Analytics must never interrupt the product interaction being measured.
+  }
+}
+
+/**
+ * Per-page-session noise control. Internal revision keys are never sent to the
+ * provider; they only prevent duplicate render events during lazy boot/reparse.
+ */
+export class UsageSession {
+  private firstEditTracked = false;
+  private renderedRevisions = new Set<number>();
+
+  trackFirstEdit(documentKind: DocumentKind): void {
+    if (this.firstEditTracked) return;
+    this.firstEditTracked = true;
+    trackUsageEvent(USAGE_EVENT_NAMES.editorChanged, {
+      document_kind: documentKind,
+    });
+  }
+
+  trackSuccessfulRender(
+    revision: number,
+    trigger: RenderTrigger,
+    documentKind: DocumentKind,
+  ): void {
+    if (this.renderedRevisions.has(revision)) return;
+    this.renderedRevisions.add(revision);
+    trackUsageEvent(USAGE_EVENT_NAMES.renderSucceeded, {
+      trigger,
+      document_kind: documentKind,
+    });
+  }
+}

playground/src/editor.ts

@@ -5,7 +5,12 @@
  * `posecode-language` (shared with the LSP), so the editor never reimplements them.
  */
 
-import { EditorState, StateEffect, StateField } from "@codemirror/state";
+import {
+  EditorState,
+  StateEffect,
+  StateField,
+  Transaction,
+} from "@codemirror/state";
 import {
   EditorView,
   keymap,
@@ -301,7 +306,7 @@ export interface PosecodeEditor {
 
 export interface PosecodeEditorOptions {
   doc: string;
-  onChange: (value: string) => void;
+  onChange: (value: string, userInitiated: boolean) => void;
 }
 
 export function createPosecodeEditor(
@@ -341,7 +346,13 @@ export function createPosecodeEditor(
           indentWithTab,
         ]),
         EditorView.updateListener.of((u) => {
-          if (u.docChanged) opts.onChange(u.state.doc.toString());
+          if (u.docChanged) {
+            const userInitiated = u.transactions.some(
+              (transaction) =>
+                transaction.annotation(Transaction.userEvent) !== undefined,
+            );
+            opts.onChange(u.state.doc.toString(), userInitiated);
+          }
         }),
       ],
     }),

playground/src/for-products.css

@@ -174,6 +174,32 @@
   font: inherit;
 }
 
+.integration-actions {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 12px;
+  margin-top: 12px;
+}
+
+.code-action,
+.docs-action {
+  color: var(--accent);
+  font: 600 11px/1.4 var(--mono);
+}
+
+.code-action {
+  padding: 0;
+  border: 0;
+  background: transparent;
+  cursor: pointer;
+}
+
+.code-action:hover,
+.docs-action:hover {
+  color: var(--text);
+}
+
 .use-cases {
   border-top: 1px solid var(--border);
 }

playground/src/for-products.ts

@@ -1,6 +1,46 @@
-import { inject } from "@vercel/analytics";
+import {
+  trackUsageEvent,
+  USAGE_EVENT_NAMES,
+  type InstallCommand,
+} from "./analytics.js";
+import { initializeAnalytics } from "./vercel-analytics.js";
 
-inject();
+initializeAnalytics();
+
+document.querySelector<HTMLElement>("[data-embed-docs]")?.addEventListener(
+  "click",
+  () => {
+    trackUsageEvent(USAGE_EVENT_NAMES.embedDocsClicked, {
+      location: "for_products",
+    });
+  },
+);
+
+for (const button of document.querySelectorAll<HTMLButtonElement>(
+  "[data-copy-command]",
+)) {
+  button.addEventListener("click", async () => {
+    const command = button.dataset.command;
+    const commandKind = button.dataset.copyCommand as
+      | InstallCommand
+      | undefined;
+    if (!command || !commandKind) return;
+    const previous = button.textContent;
+    try {
+      await navigator.clipboard.writeText(command);
+      button.textContent = "Copied ✓";
+      trackUsageEvent(USAGE_EVENT_NAMES.installCommandCopied, {
+        command: commandKind,
+        location: "for_products",
+      });
+    } catch {
+      button.textContent = "Copy failed";
+    }
+    window.setTimeout(() => {
+      button.textContent = previous;
+    }, 1500);
+  });
+}
 
 const prefersReducedMotion = matchMedia("(prefers-reduced-motion: reduce)").matches;