diff --git a/tests/runner-e2e/PRODUCT-JOURNEYS.md b/tests/runner-e2e/PRODUCT-JOURNEYS.md
index 296dbc6309f..ed5f8c2cc83 100644
--- a/tests/runner-e2e/PRODUCT-JOURNEYS.md
+++ b/tests/runner-e2e/PRODUCT-JOURNEYS.md
@@ -33,6 +33,10 @@ never start a server or depend on a tenant filesystem.
 | `stop-redirect` | Native agent; three work runs; qualified Docker oracle | Download a verified checkpoint, Stop an active revision, require native cancellation acknowledgement, submit a new direction once and verify completion without original-run activity |
 | `cloud-onboarding` | Signed-in admitted Cloud account; fresh workspace; qualified bounded provider route | Create workspace in the portal, connect API key and native Codex agent in the wizard, complete a task, download and independently check its artifact |
 
+The shared Studio helper waits for the original saved file body before typing.
+An editor control can mount before the file query completes; editing that empty
+draft can otherwise lose the original content when the file arrives.
+
 Supported acquisitions are managed self-hosted (`local`), registered existing
 Cloud (`local` or `daytona` when present), and new Cloud. New Cloud must start
 with onboarding. Its context can then satisfy the identical task-properties
diff --git a/tests/runner-e2e/playwright-support.config.ts b/tests/runner-e2e/playwright-support.config.ts
index 8d2bd94f902..a21d78db448 100644
--- a/tests/runner-e2e/playwright-support.config.ts
+++ b/tests/runner-e2e/playwright-support.config.ts
@@ -3,7 +3,7 @@ import { defineConfig } from "@playwright/test";
 /** Browser-only harness regressions: no Paperclip instance or provider credentials. */
 export default defineConfig({
   testDir: ".",
-  testMatch: ["native-task-reply.spec.ts", "screenshot-readiness.spec.ts", "service-worker-reload.spec.ts", "lost-send.spec.ts", "chat-restart.spec.ts", "settings-toggle.spec.ts", "browser-bootstrap-diagnostics.spec.ts", "service-worker-module-loading.spec.ts", "browser-bootstrap-recovery.spec.ts", "blocker-input.spec.ts", "native-blocker-visible.spec.ts", "copilot-permission-card.spec.ts", "github-review-check.spec.ts", "antigravity-journey-browser.spec.ts"],
+  testMatch: ["skill-studio-flow.spec.ts", "native-task-reply.spec.ts", "screenshot-readiness.spec.ts", "service-worker-reload.spec.ts", "lost-send.spec.ts", "chat-restart.spec.ts", "settings-toggle.spec.ts", "browser-bootstrap-diagnostics.spec.ts", "service-worker-module-loading.spec.ts", "browser-bootstrap-recovery.spec.ts", "blocker-input.spec.ts", "native-blocker-visible.spec.ts", "copilot-permission-card.spec.ts", "github-review-check.spec.ts", "antigravity-journey-browser.spec.ts"],
   workers: 1,
   retries: 0,
   timeout: 10_000,
diff --git a/tests/runner-e2e/skill-studio-flow.spec.ts b/tests/runner-e2e/skill-studio-flow.spec.ts
new file mode 100644
index 00000000000..a27c3ff32b8
--- /dev/null
+++ b/tests/runner-e2e/skill-studio-flow.spec.ts
@@ -0,0 +1,45 @@
+import { expect, test } from "@playwright/test";
+import { editCreatedSkillThroughStudio } from "./skill-studio-flow.js";
+
+for (const hydrationMs of [0, 1500]) test(`Studio preserves the loaded file before editing (${hydrationMs}ms hydration)`, async ({ page }) => {
+  const skillId = "owned-skill", skillName = "owned-qa-skill", marker = "Studio edit marker: owned-campaign";
+  let saved = "Verify checks.", saves = 0;
+  await page.exposeFunction("saveSkill", (body: string) => { saved = body; saves++; });
+  await page.route("https://fixture.test/**", async route => {
+    const studio = new URL(route.request().url()).pathname.includes("/skills/studio/");
+    const body = studio ? `<button role="combobox">${skillName}</button>
+      <div role="textbox" aria-label="editable markdown" contenteditable="true"></div>
+      <button id="save">Save</button>
+      <script>
+        const editor=document.querySelector('[contenteditable]');
+        setTimeout(()=>{editor.innerText=${JSON.stringify(saved)}},${hydrationMs});
+        document.querySelector('#save').onclick=()=>window.saveSkill(editor.innerText);
+      </script>` : `<article aria-label="Skill created: ${skillName}"><button id="card">View skill</button></article>
+      <section id="detail" hidden><h2>${skillName}</h2>${saved.split(/\n+/).map(line => `<p>${line}</p>`).join("")}
+      <a role="button" href="/QA/skills/studio/${skillId}">Open in Skill Studio</a></section>
+      <script>document.querySelector('#card').onclick=()=>document.querySelector('#detail').hidden=false</script>`;
+    await route.fulfill({ contentType: "text/html", body });
+  });
+  await page.goto("https://fixture.test/QA/issues/QA-1");
+  await editCreatedSkillThroughStudio({ page, skillId, skillName, marker, deadlineAt: Date.now() + 8000,
+    read: async () => ({ content: saved }) });
+  expect(saves).toBe(1);
+  expect(saved).toContain("Verify checks.");
+  expect(saved).toContain(marker);
+});
+
+test("Studio never edits or saves an unhydrated file", async ({ page }) => {
+  let saves = 0, inputs = 0;
+  await page.exposeFunction("savedUnloadedFile", () => { saves++; });
+  await page.exposeFunction("editedUnloadedFile", () => { inputs++; });
+  await page.route("https://fixture.test/**", route => route.fulfill({ contentType: "text/html", body:
+    `<article aria-label="Skill created: owned"><button onclick="document.querySelector('section').hidden=false">View</button></article>
+    <section hidden><h2>owned</h2><p>Verify checks.</p><a role="button" href="/QA/skills/studio/id">Open in Skill Studio</a></section>
+    <button role="combobox">owned</button><div contenteditable="true" role="textbox" aria-label="editable markdown" oninput="window.editedUnloadedFile()"></div>
+    <button onclick="window.savedUnloadedFile()">Save</button>` }));
+  await page.goto("https://fixture.test/QA/issues/QA-1");
+  await expect(editCreatedSkillThroughStudio({ page, skillId: "id", skillName: "owned", marker: "New content", deadlineAt: Date.now() + 7000,
+    read: async () => ({}) })).rejects.toThrow();
+  expect(inputs).toBe(0);
+  expect(saves).toBe(0);
+});
diff --git a/tests/runner-e2e/skill-studio-flow.ts b/tests/runner-e2e/skill-studio-flow.ts
index 7b12ba3e82c..686bfa1a0e4 100644
--- a/tests/runner-e2e/skill-studio-flow.ts
+++ b/tests/runner-e2e/skill-studio-flow.ts
@@ -16,6 +16,9 @@ export async function editCreatedSkillThroughStudio(input: {
   await expect(page).toHaveURL(new RegExp(`/skills/studio/${input.skillId}$`));
   await expect(page.getByRole("combobox").filter({ hasText: skillName })).toBeVisible();
   const editor = page.getByRole("textbox", { name: "editable markdown", exact: true });
+  // Studio mounts the editor before its file query completes. Wait for the
+  // saved body, otherwise hydration can replace edits made to the empty draft.
+  await expect(editor).toContainText("Verify checks.");
   await editor.click();
   await editor.press("ControlOrMeta+End");
   await editor.press("Enter");