diff --git a/docs/refactor/arc-1-smoke-checklist.md b/docs/refactor/arc-1-smoke-checklist.md
new file mode 100644
index 0000000..f3bbb8f
--- /dev/null
+++ b/docs/refactor/arc-1-smoke-checklist.md
@@ -0,0 +1,75 @@
+# Arc 1 Smoke Checklist
+
+This checklist is the manual checkpoint for Arc 1.
+
+It is intentionally short and focused on the editor flows that must remain usable while the refactor branch is in motion.
+
+## Preconditions
+
+- start the Vite client with `npm run dev`
+- start the API server with `npm run dev:api`
+- open the launcher at the local dev URL
+
+## Checklist
+
+### 1. Launcher Opens
+
+- verify the launcher renders
+- verify the primary launch actions are visible
+- verify the `Content Editor` action is available
+
+### 2. Content Editor Loads
+
+- open the content editor from the launcher
+- verify the content editor window loads
+- verify the main content domains are listed:
+  - NPCs
+  - Dialogues
+  - Monsters
+  - Items
+  - Abilities
+  - Loot Tables
+  - Quests
+  - Graphics
+  - Factions
+
+### 3. Content Record Edit Round Trip
+
+- open any existing content record
+- change one small field value
+- use `Commit`
+- use `Save`
+- verify the save status updates
+- revert the field to its original value
+- save again so the repository returns to its original content state
+
+### 4. Studio Window Opens
+
+- open the studio from the launcher
+- verify the studio bootstraps into a world without console-blocking errors
+
+### 5. World Loads And A Tile Edit Still Works
+
+- verify the current world name and dimensions are visible
+- select a tile
+- paint one tile on the map
+- verify undo/save state updates
+- save the world
+- revert the tile change before finishing the checkpoint
+
+### 6. Graphics Painter Opens And Saves
+
+- open the graphics browser from the studio
+- open a sprite or tile asset in the painter
+- change one pixel
+- save the asset
+- revert the pixel change before finishing the checkpoint
+
+## Verification Notes
+
+Checkpoint commits for Arc 1 should only be considered shareable when:
+
+- `npm test` passes
+- `npm run build` passes
+- this checklist passes
+- temporary smoke-test content edits have been reverted before commit
diff --git a/src/WorldshaperLauncher.tsx b/src/WorldshaperLauncher.tsx
index 22d1196..0cec1cb 100644
--- a/src/WorldshaperLauncher.tsx
+++ b/src/WorldshaperLauncher.tsx
@@ -683,6 +683,16 @@ function openSharedContractNote(): void {
   window.location.assign(noteUrl.toString());
 }
 
+function openContentEditor(): void {
+  const editorUrl = new URL("./worldshaper-content.html", window.location.href);
+  const popup = window.open(editorUrl.toString(), "worldshaper-content-editor", "popup=yes,width=1600,height=980,resizable=yes,scrollbars=yes");
+  if (popup) {
+    popup.focus();
+    return;
+  }
+  window.location.assign(editorUrl.toString());
+}
+
 function openAdminPanelWindow(): boolean {
   const nextUrl = new URL(window.location.href);
   nextUrl.searchParams.set("admin", "requests");
@@ -1364,6 +1374,9 @@ function WorldshaperLauncher() {
                 <button type="button" className="launcher-primary-btn" onClick={() => void handleLaunch()} disabled={isBusy}>
                   Launch
                 </button>
+                <button type="button" className="launcher-secondary-btn" onClick={openContentEditor} disabled={isBusy}>
+                  Content Editor
+                </button>
                 <button type="button" className="launcher-secondary-btn" onClick={openSharedContractNote} disabled={isBusy}>
                   Shared Contract
                 </button>
diff --git a/src/contentMain.tsx b/src/contentMain.tsx
new file mode 100644
index 0000000..9f2cb63
--- /dev/null
+++ b/src/contentMain.tsx
@@ -0,0 +1,11 @@
+import { StrictMode } from "react";
+import { createRoot } from "react-dom/client";
+import "./index.css";
+import "./App.css";
+import App from "./App";
+
+createRoot(document.getElementById("root")!).render(
+  <StrictMode>
+    <App />
+  </StrictMode>,
+);
diff --git a/vite.config.ts b/vite.config.ts
index 6d59436..e66638d 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -28,6 +28,7 @@ export default defineConfig({
     rollupOptions: {
       input: {
         main: resolve(__dirname, "index.html"),
+        worldshaperContent: resolve(__dirname, "worldshaper-content.html"),
         futureSharedContract: resolve(__dirname, "Future - Shared Contract.html"),
         worldshaperStudio: resolve(__dirname, "worldshaper-studio.html"),
         worldshaperHeightViewer: resolve(__dirname, "worldshaper-height-viewer.html"),
diff --git a/worldshaper-content.html b/worldshaper-content.html
new file mode 100644
index 0000000..bc30fa2
--- /dev/null
+++ b/worldshaper-content.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Worldshaper Content Editor</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/contentMain.tsx"></script>
+  </body>
+</html>