diff --git a/apps/extension/src/tools/__tests__/interaction.test.ts b/apps/extension/src/tools/__tests__/interaction.test.ts
index 8184b6dc..2206f3d9 100644
--- a/apps/extension/src/tools/__tests__/interaction.test.ts
+++ b/apps/extension/src/tools/__tests__/interaction.test.ts
@@ -1511,6 +1511,71 @@ describe("handleFill", () => {
     expect(callFns).toHaveLength(5);
   });
 
+  it("routes fill typing into the ref's OOPIF child session", async () => {
+    // DOM.focus already resolves the node in its own session; the typing
+    // that follows must use the same session, or the text lands in the
+    // main frame while the OOPIF field stays empty (issue #438).
+    const sm = new SessionManager({ agentWindow: fakeAgentWindow([100]) });
+    const ctx = await sm.start("aa11");
+    ctx.refStore.set("e3", 1234, {
+      tabId: 4,
+      frameId: "child-frame",
+      cdpSessionId: "child-session",
+    });
+    const fake = makeFakeCdp({
+      "DOM.scrollIntoViewIfNeeded": () => ({}),
+      "Runtime.evaluate": () => ({ result: { value: { width: 200, height: 100 } } }),
+      "Page.getLayoutMetrics": () => ({
+        cssLayoutViewport: { clientWidth: 200, clientHeight: 100 },
+      }),
+    });
+    fake.cdp.getFrameGraph = vi.fn(async () => ({
+      rootFrameId: "main",
+      frames: [
+        { frameId: "main", target: { tabId: 4 } },
+        {
+          frameId: "child-frame",
+          parentFrameId: "main",
+          ownerBackendNodeId: 99,
+          target: { tabId: 4, sessionId: "child-session" },
+        },
+      ],
+    }));
+    const targetCalls: Array<{ sessionId?: string; method: string }> = [];
+    fake.cdp.sendToTarget = vi.fn(async (target, method, params) => {
+      targetCalls.push({ sessionId: target.sessionId, method });
+      if (method === "DOM.describeNode") {
+        return {
+          node: { backendNodeId: 1234, nodeName: "INPUT", attributes: ["type", "text"] },
+        };
+      }
+      if (method === "DOM.scrollIntoViewIfNeeded") return {};
+      if (method === "DOM.focus") return {};
+      if (method === "DOM.resolveNode") return { object: { objectId: "obj-oopif" } };
+      if (method === "Runtime.callFunctionOn") return successfulFillScript(params);
+      if (method === "Runtime.releaseObject") return {};
+      if (method === "Input.insertText") return {};
+      if (method === "Runtime.evaluate") return { result: { value: { width: 200, height: 100 } } };
+      if (method === "Page.getLayoutMetrics") {
+        return { cssLayoutViewport: { clientWidth: 200, clientHeight: 100 } };
+      }
+      throw new Error(`unexpected child CDP call ${method}`);
+    }) as CdpRunner["sendToTarget"];
+
+    const res = await handleFill(
+      sm,
+      { session_id: "aa11", ref: "@e3", value: "hello" },
+      { cdp: fake.cdp, tabsApi: fake.tabsApi },
+    );
+    if ("code" in res) throw new Error(`unexpected error: ${JSON.stringify(res)}`);
+    expect(res.value_length).toBe(5);
+    const childTyping = targetCalls.filter(
+      (c) => c.method === "Input.insertText" || c.method === "Input.dispatchKeyEvent",
+    );
+    expect(childTyping.map((c) => c.sessionId)).toContain("child-session");
+    expect(fake.sent.filter((c) => c.method.startsWith("Input."))).toHaveLength(0);
+  });
+
   it("passes clear_before=false to preparation and verifies the result", async () => {
     const sm = new SessionManager({ agentWindow: fakeAgentWindow([100]) });
     const ctx = await sm.start("aa11");
@@ -1772,6 +1837,66 @@ describe("handlePress", () => {
     expect(res.key).toBe("Enter");
   });
 
+  it("routes press key events into the ref's OOPIF child session", async () => {
+    // A ref inside an OOPIF carries cdpSessionId; key events must reach
+    // that child session (which owns the focused element), not the root
+    // one the tab-level send hits (issue #438).
+    const sm = new SessionManager({ agentWindow: fakeAgentWindow([100]) });
+    const ctx = await sm.start("aa11");
+    ctx.refStore.set("e3", 1234, {
+      tabId: 4,
+      frameId: "child-frame",
+      cdpSessionId: "child-session",
+    });
+    const fake = makeFakeCdp({
+      "Input.dispatchKeyEvent": () => ({}),
+      "DOM.scrollIntoViewIfNeeded": () => ({}),
+      "Runtime.evaluate": () => ({ result: { value: { width: 200, height: 100 } } }),
+      "Page.getLayoutMetrics": () => ({
+        cssLayoutViewport: { clientWidth: 200, clientHeight: 100 },
+      }),
+    });
+    fake.cdp.getFrameGraph = vi.fn(async () => ({
+      rootFrameId: "main",
+      frames: [
+        { frameId: "main", target: { tabId: 4 } },
+        {
+          frameId: "child-frame",
+          parentFrameId: "main",
+          ownerBackendNodeId: 99,
+          target: { tabId: 4, sessionId: "child-session" },
+        },
+      ],
+    }));
+    const targetCalls: Array<{ sessionId?: string; method: string }> = [];
+    fake.cdp.sendToTarget = vi.fn(async (target, method) => {
+      targetCalls.push({ sessionId: target.sessionId, method });
+      if (method === "DOM.scrollIntoViewIfNeeded") return {};
+      if (method === "DOM.focus") return {};
+      if (method === "Input.dispatchKeyEvent") return {};
+      if (method === "Runtime.evaluate") return { result: { value: { width: 200, height: 100 } } };
+      if (method === "Page.getLayoutMetrics") {
+        return { cssLayoutViewport: { clientWidth: 200, clientHeight: 100 } };
+      }
+      throw new Error(`unexpected child CDP call ${method}`);
+    }) as CdpRunner["sendToTarget"];
+
+    const res = await handlePress(
+      sm,
+      { session_id: "aa11", key: "Enter", ref: "@e3" },
+      { cdp: fake.cdp, tabsApi: fake.tabsApi },
+    );
+    expectPressOk(res);
+    // Every key event went to the child session; none to the root.
+    const childKeyEvents = targetCalls.filter((c) => c.method === "Input.dispatchKeyEvent");
+    expect(childKeyEvents.map((c) => c.sessionId)).toEqual([
+      "child-session",
+      "child-session",
+      "child-session",
+    ]);
+    expect(fake.sent.filter((c) => c.method === "Input.dispatchKeyEvent")).toHaveLength(0);
+  });
+
   it.each([
     "focus",
     "key",
diff --git a/apps/extension/src/tools/interaction.ts b/apps/extension/src/tools/interaction.ts
index a1889d98..5df8aeb8 100644
--- a/apps/extension/src/tools/interaction.ts
+++ b/apps/extension/src/tools/interaction.ts
@@ -1278,12 +1278,12 @@ export async function handleFill(
       // end command can escape a nested editing host. Place its range below.
       // Neither event carries an End key that could invoke a page shortcut.
       try {
-        await deps.cdp.send(target.tabId, "Input.dispatchKeyEvent", {
+        await nodeCdp.send(target.tabId, "Input.dispatchKeyEvent", {
           type: "rawKeyDown",
           commands: native ? ["moveToEndOfDocument"] : [],
         });
       } finally {
-        await deps.cdp.send(target.tabId, "Input.dispatchKeyEvent", { type: "keyUp" });
+        await nodeCdp.send(target.tabId, "Input.dispatchKeyEvent", { type: "keyUp" });
       }
       if (throwIfAborted(deps.signal)) {
         return { code: "cancelled", message: "fill aborted" };
@@ -1309,7 +1309,7 @@ export async function handleFill(
     if (params.value !== "") {
       // Normalize the actual input as well as the expected value: older Chrome
       // versions retain CR in editors or turn CRLF into two textarea breaks.
-      await deps.cdp.send(target.tabId, "Input.insertText", {
+      await nodeCdp.send(target.tabId, "Input.insertText", {
         text: params.value.replace(/\r\n?/g, "\n"),
       });
     }
@@ -1568,6 +1568,10 @@ export async function handlePress(
       ? await resolveBackendNode(deps.cdp, ctx, target, params, "press")
       : undefined;
   if (node && isRpcError(node)) return node;
+  // Key events must reach the focused element's session: for a ref inside
+  // an OOPIF that is the child session, not the root one the tab-level
+  // send would hit (issue #438). Without a ref the root session is correct.
+  const keyCdp = node ? cdpRunnerForTarget(deps.cdp, node.cdpTarget) : deps.cdp;
   return withInputReady(ctx, target.tabId, { ...deps, deadline }, async (input) => {
     // Optional focus before key dispatch.
     if (node) {
@@ -1607,7 +1611,7 @@ export async function handlePress(
       deps.cdp.trackSessionTab?.(ctx.sessionId, target.tabId);
       deps.onInputSent?.(target.tabId);
       input.markSent();
-      await deps.cdp.send(target.tabId, "Input.dispatchKeyEvent", {
+      await keyCdp.send(target.tabId, "Input.dispatchKeyEvent", {
         type: "rawKeyDown",
         key: descriptor.key,
         code: descriptor.code,
@@ -1621,7 +1625,7 @@ export async function handlePress(
         typeof descriptor.text === "string" &&
         descriptor.text.length > 0
       ) {
-        await deps.cdp.send(target.tabId, "Input.dispatchKeyEvent", {
+        await keyCdp.send(target.tabId, "Input.dispatchKeyEvent", {
           type: "char",
           key: descriptor.key,
           code: descriptor.code,
@@ -1639,7 +1643,7 @@ export async function handlePress(
         }
       }
       deps.onInputSent?.(target.tabId);
-      await deps.cdp.send(target.tabId, "Input.dispatchKeyEvent", {
+      await keyCdp.send(target.tabId, "Input.dispatchKeyEvent", {
         type: "keyUp",
         key: descriptor.key,
         code: descriptor.code,