diff --git a/apps/web/src/components/chat/ComposerPendingUserInputPanel.navigation.browser.test.tsx b/apps/web/src/components/chat/ComposerPendingUserInputPanel.navigation.browser.test.tsx
index e6eecd6ad6f86..788416a545f0e 100644
--- a/apps/web/src/components/chat/ComposerPendingUserInputPanel.navigation.browser.test.tsx
+++ b/apps/web/src/components/chat/ComposerPendingUserInputPanel.navigation.browser.test.tsx
@@ -16,6 +16,7 @@ vi.mock(import("../ChatMarkdown"), async (importOriginal) => ({
 
 import { act, fakeTimers, render } from "../../../test/render";
 import { makeThreadProjectionFixture } from "../../test-fixtures";
+import { ComposerPendingUserInputPanel } from "./ComposerPendingUserInputPanel";
 import { usePendingThreadRequests } from "./usePendingThreadRequests";
 
 const threadRef = { environmentId: EnvironmentId.make("env"), threadId: ThreadId.make("thread") };
@@ -181,3 +182,90 @@ it("isolates drafts by environment, thread and request and discards only resolve
     );
   }
 });
+
+it("answers an option with Space on keyup, once per press, and not after focus leaves", async () => {
+  const onToggleOption = vi.fn();
+  await using screen = await render(
+    <ComposerPendingUserInputPanel
+      pendingUserInputs={[
+        { ...prompt, questions: [{ ...prompt.questions[0]!, multiSelect: true }] },
+      ]}
+      cwd={undefined}
+      threadRef={threadRef}
+      respondingRequestIds={[]}
+      answers={{}}
+      questionIndex={0}
+      onToggleOption={onToggleOption}
+      onAdvance={() => {}}
+      onDismiss={() => {}}
+    />,
+  );
+  const option = screen.getByRole("button", { name: /Incremental/ }).element() as HTMLElement;
+  const key = (type: "keydown" | "keyup", key: string, repeat = false) =>
+    act(() => {
+      option.dispatchEvent(new KeyboardEvent(type, { key, repeat, bubbles: true }));
+    });
+
+  option.focus();
+  await key("keydown", " ");
+  await key("keydown", " ", true);
+  await key("keydown", " ", true);
+  expect(onToggleOption).not.toHaveBeenCalled();
+  await key("keyup", " ");
+  expect(onToggleOption).toHaveBeenCalledTimes(1);
+
+  await key("keydown", " ");
+  await act(() => option.blur());
+  option.focus();
+  await key("keyup", " ");
+  expect(onToggleOption).toHaveBeenCalledTimes(1);
+
+  await key("keydown", "Enter");
+  expect(onToggleOption).toHaveBeenCalledTimes(2);
+
+  const modifiedEnter = new KeyboardEvent("keydown", {
+    key: "Enter",
+    metaKey: true,
+    shiftKey: true,
+    bubbles: true,
+    cancelable: true,
+  });
+  await act(() => {
+    option.dispatchEvent(modifiedEnter);
+  });
+  expect(modifiedEnter.defaultPrevented).toBe(false);
+  expect(onToggleOption).toHaveBeenCalledTimes(2);
+});
+
+it("ignores a pointer click that ends a text selection but still answers assistive activation", async () => {
+  const onToggleOption = vi.fn();
+  await using screen = await render(
+    <ComposerPendingUserInputPanel
+      pendingUserInputs={[
+        { ...prompt, questions: [{ ...prompt.questions[0]!, multiSelect: true }] },
+      ]}
+      cwd={undefined}
+      threadRef={threadRef}
+      respondingRequestIds={[]}
+      answers={{}}
+      questionIndex={0}
+      onToggleOption={onToggleOption}
+      onAdvance={() => {}}
+      onDismiss={() => {}}
+    />,
+  );
+  const option = screen.getByRole("button", { name: /Incremental/ }).element() as HTMLElement;
+  const range = document.createRange();
+  range.selectNodeContents(option);
+  window.getSelection()!.removeAllRanges();
+  window.getSelection()!.addRange(range);
+  const click = (detail: number) =>
+    act(() => {
+      option.dispatchEvent(new MouseEvent("click", { detail, bubbles: true }));
+    });
+
+  await click(1);
+  expect(onToggleOption).not.toHaveBeenCalled();
+  await click(0);
+  expect(onToggleOption).toHaveBeenCalledTimes(1);
+});
diff --git a/apps/web/src/components/chat/ComposerPendingUserInputPanel.tsx b/apps/web/src/components/chat/ComposerPendingUserInputPanel.tsx
index 99f80d8e50813..56f831083de72 100644
--- a/apps/web/src/components/chat/ComposerPendingUserInputPanel.tsx
+++ b/apps/web/src/components/chat/ComposerPendingUserInputPanel.tsx
@@ -85,6 +85,7 @@ const ComposerPendingUserInputCard = memo(function ComposerPendingUserInputCard(
   const canRespond = prompt.responseCapability !== "not_resumable";
   const responseDisabled = disabled || isResponding || !canRespond;
   const autoAdvanceTimerRef = useRef<number | null>(null);
+  const spacePressedOptionRef = useRef<HTMLElement | null>(null);
   const advance = useStableCallback(onAdvance);
   const [optimisticSingleSelect, setOptimisticSingleSelect] = useState<{
     questionId: string;
@@ -250,7 +251,7 @@ const ComposerPendingUserInputCard = memo(function ComposerPendingUserInputCard(
                   isOptimisticallySelected || draftSelectedOptions?.[index] === true;
                 const shortcutKey = index < 9 ? index + 1 : null;
                 const className = cn(
-                  "group flex w-full items-center gap-2 rounded-md px-2.5 py-2 text-left outline-none transition-colors duration-150 focus-visible:ring-1 focus-visible:ring-inset focus-visible:ring-primary/25",
+                  "group flex w-full select-text items-center gap-2 rounded-md px-2.5 py-2 text-left outline-none transition-colors duration-150 focus-visible:ring-1 focus-visible:ring-inset focus-visible:ring-primary/25",
                   isSelected
                     ? "bg-muted/55 text-foreground"
                     : "bg-transparent text-foreground/85 hover:bg-muted/30",
@@ -278,18 +279,55 @@ const ComposerPendingUserInputCard = memo(function ComposerPendingUserInputCard(
                     ) : null}
                   </>
                 );
+                // Chromium cannot start a text selection inside a native <button>, so the
+                // option is a button-role div whose label and description stay copyable.
                 return (
-                  <button
+                  <div
                     key={`${activeQuestion.id}:${optionValue}`}
-                    type="button"
-                    disabled={disabled || isResponding}
-                    onClick={() => {
+                    role="button"
+                    tabIndex={disabled || isResponding ? -1 : 0}
+                    aria-disabled={disabled || isResponding}
+                    onClick={(event) => {
+                      // A drag that selected text in the option ends in a click; it must not answer.
+                      // Assistive technology activates with detail 0 and still answers.
+                      const selection = window.getSelection();
+                      if (
+                        event.detail > 0 &&
+                        selection &&
+                        !selection.isCollapsed &&
+                        selection.containsNode(event.currentTarget, true)
+                      ) {
+                        return;
+                      }
                       handleOptionSelection(activeQuestion.id, optionValue);
                     }}
+                    // Native button keys: Enter answers on keydown, Space on keyup, and
+                    // blurring while Space is held cancels it. Modified keys stay with global
+                    // shortcuts such as Mod+Shift+Enter.
+                    onKeyDown={(event) => {
+                      if (event.metaKey || event.ctrlKey || event.altKey) return;
+                      if (event.key === "Enter") {
+                        event.preventDefault();
+                        handleOptionSelection(activeQuestion.id, optionValue);
+                      } else if (event.key === " ") {
+                        event.preventDefault();
+                        if (!event.repeat) spacePressedOptionRef.current = event.currentTarget;
+                      }
+                    }}
+                    onKeyUp={(event) => {
+                      if (event.key !== " ") return;
+                      const pressed = spacePressedOptionRef.current === event.currentTarget;
+                      spacePressedOptionRef.current = null;
+                      if (event.metaKey || event.ctrlKey || event.altKey) return;
+                      if (pressed) handleOptionSelection(activeQuestion.id, optionValue);
+                    }}
+                    onBlur={() => {
+                      spacePressedOptionRef.current = null;
+                    }}
                     className={className}
                   >
                     {content}
-                  </button>
+                  </div>
                 );
               })}
             </div>
diff --git a/apps/web/test/fixtures/pending-user-input/README.md b/apps/web/test/fixtures/pending-user-input/README.md
new file mode 100644
index 0000000000000..18fa86914fa0f
--- /dev/null
+++ b/apps/web/test/fixtures/pending-user-input/README.md
@@ -0,0 +1,19 @@
+# Pending question evidence fixtures
+
+Run `node apps/web/test/fixtures/pending-user-input/request.mjs multi` or
+`node apps/web/test/fixtures/pending-user-input/request.mjs single` from the repo
+root. Paste the output into a Claude thread in an isolated development server.
+The provider must only ask the question; it must not execute the example command.
+
+`multi` exercises wrapped labels and descriptions, inline question code, an empty
+description, and a description identical to its label. Select **Wait** for the
+matched stills, leaving the other options unselected. Keep the request pending
+while testing selection, clipboard paste, ordinary clicks, keyboard activation,
+and collapse/reopen. `single` has a nonterminal and terminal question. Reissue it
+for each activation method because the terminal answer consumes the request.
+
+These are public synthetic inputs, not database rows or provider credentials.
+Provider-generated request/question identifiers can differ. Claude's four-option
+limit prevents this live fixture from covering the ninth/tenth option. Permission
+disabled, in-flight responding, and nonresumable states require separate real
+runtime conditions; changing these inputs does not establish those conditions.
diff --git a/apps/web/test/fixtures/pending-user-input/questions.json b/apps/web/test/fixtures/pending-user-input/questions.json
new file mode 100644
index 0000000000000..3850ad3f0fa94
--- /dev/null
+++ b/apps/web/test/fixtures/pending-user-input/questions.json
@@ -0,0 +1,78 @@
+{
+  "multi": [
+    {
+      "id": "selection-test",
+      "header": "Selection test",
+      "question": "Which command should handle ticket T3-16821? Inspect `git status --short` before proceeding.",
+      "multiSelect": true,
+      "options": [
+        {
+          "label": "Inspect a long command and its harmless temporary working directory",
+          "description": "Run git status --short in /tmp/repro\nKeep ticket T3-16821 pending until review is complete."
+        },
+        {
+          "label": "Wait",
+          "description": "Leave ticket T3-16821 pending"
+        },
+        {
+          "label": "No description",
+          "description": ""
+        },
+        {
+          "label": "Same description",
+          "description": "Same description"
+        }
+      ]
+    }
+  ],
+  "single": [
+    {
+      "id": "single-first",
+      "header": "First question",
+      "question": "Which command should handle ticket T3-16821? Inspect `git status --short` before proceeding.",
+      "multiSelect": false,
+      "options": [
+        {
+          "label": "Inspect a long command and its harmless temporary working directory",
+          "description": "Run git status --short in /tmp/repro\nKeep ticket T3-16821 pending until review is complete."
+        },
+        {
+          "label": "Wait",
+          "description": "Leave ticket T3-16821 pending"
+        },
+        {
+          "label": "No description",
+          "description": ""
+        },
+        {
+          "label": "Same description",
+          "description": "Same description"
+        }
+      ]
+    },
+    {
+      "id": "single-final",
+      "header": "Final question",
+      "question": "Which harmless choice should finish ticket T3-16821?",
+      "multiSelect": false,
+      "options": [
+        {
+          "label": "Inspect a long command and its harmless temporary working directory",
+          "description": "Run git status --short in /tmp/repro\nKeep ticket T3-16821 pending until review is complete."
+        },
+        {
+          "label": "Wait",
+          "description": "Leave ticket T3-16821 pending"
+        },
+        {
+          "label": "No description",
+          "description": ""
+        },
+        {
+          "label": "Same description",
+          "description": "Same description"
+        }
+      ]
+    }
+  ]
+}
diff --git a/apps/web/test/fixtures/pending-user-input/request.mjs b/apps/web/test/fixtures/pending-user-input/request.mjs
new file mode 100644
index 0000000000000..99c7d85213037
--- /dev/null
+++ b/apps/web/test/fixtures/pending-user-input/request.mjs
@@ -0,0 +1,17 @@
+import * as NodeFS from "node:fs";
+
+const fixtures = JSON.parse(
+  NodeFS.readFileSync(new URL("./questions.json", import.meta.url), "utf8"),
+);
+const shape = process.argv[2] ?? "multi";
+if (shape !== "multi" && shape !== "single") {
+  throw new Error("Usage: node request.mjs [multi|single]");
+}
+
+console.log(
+  "Call only AskUserQuestion with the questions below. Do not execute commands, edit files, " +
+    "or use other tools. Preserve the text exactly, including the description newline. " +
+    "The id fields are fixture identifiers; omit them if the provider schema disallows them. " +
+    "Leave the request pending. When answered, acknowledge the choices without taking action.\n\n" +
+    JSON.stringify({ questions: fixtures[shape] }, null, 2),
+);