feat(desktop): streamline nostr identity pairing (#1974)

Signed-off-by: npub1ntr8jjcqq6gt06q5avvqttfjgpwshmra22pcmcagdnukw4ja4nqqsa9g54 <9ac6794b000690b7e814eb1805ad32405d0bec7d52838de3a86cf967565dacc0@sprout-oss.stage.blox.sqprod.co>
Co-authored-by: npub1ntr8jjcqq6gt06q5avvqttfjgpwshmra22pcmcagdnukw4ja4nqqsa9g54 <9ac6794b000690b7e814eb1805ad32405d0bec7d52838de3a86cf967565dacc0@sprout-oss.stage.blox.sqprod.co>

desktop/src/features/profile/ui/NostrBindConsentDialog.tsx

@@ -1,5 +1,6 @@
 import * as DialogPrimitive from "@radix-ui/react-dialog";
 import { openUrl } from "@tauri-apps/plugin-opener";
+import { ChevronDown } from "lucide-react";
 import { AnimatePresence, motion, useReducedMotion } from "motion/react";
 import * as React from "react";
 import { toast } from "sonner";
@@ -88,6 +89,11 @@ function normalizeVerificationCode(value: string): string[] {
     .map((character) => character.trim());
 }
 
+function isNostrBindRequestExpired(payload: NostrBindDeepLinkPayload): boolean {
+  const expiry = new Date(payload.expiresAt).getTime();
+  return Number.isNaN(expiry) || expiry <= Date.now();
+}
+
 function formatError(error: unknown): string {
   if (error instanceof Error) {
     return error.message;
@@ -135,6 +141,74 @@ async function returnSignedResponseToBrowser(
   }
 }
 
+function SignedResponseControls({
+  copyFailed,
+  copyLabel,
+  onCopy,
+  signedResponse,
+}: {
+  copyFailed: boolean;
+  copyLabel: string;
+  onCopy: () => void;
+  signedResponse: string;
+}) {
+  return (
+    <div className="space-y-4" data-testid="nostr-bind-manual-fallback-content">
+      <pre
+        className="max-h-56 w-full overflow-auto rounded-2xl border border-border/70 bg-muted/60 p-4 text-left shadow-xs"
+        data-testid="nostr-bind-signed-response"
+      >
+        <code className="whitespace-pre-wrap break-all font-mono text-xs leading-5 text-foreground">
+          {signedResponse}
+        </code>
+      </pre>
+
+      {copyFailed ? (
+        <p className="w-full rounded-md border border-destructive/30 bg-destructive/10 px-3 py-2 text-left text-sm text-destructive">
+          {COPY_FAILURE_MESSAGE}
+        </p>
+      ) : null}
+
+      <Button
+        aria-label={copyLabel}
+        className="h-10 w-full"
+        data-testid="nostr-bind-copy-response"
+        onClick={onCopy}
+        type="button"
+      >
+        <span aria-live="polite" className="sr-only">
+          {copyLabel}
+        </span>
+        <span
+          aria-hidden="true"
+          className="inline-grid h-5 place-items-center overflow-hidden"
+        >
+          <span
+            className={cn(
+              COPY_BUTTON_LABEL_CLASS,
+              copyLabel === "Copy response"
+                ? "translate-y-0 opacity-100"
+                : "-translate-y-0.5 opacity-0",
+            )}
+          >
+            Copy response
+          </span>
+          <span
+            className={cn(
+              COPY_BUTTON_LABEL_CLASS,
+              copyLabel === "Copied"
+                ? "translate-y-0 opacity-100"
+                : "translate-y-0.5 opacity-0",
+            )}
+          >
+            Copied
+          </span>
+        </span>
+      </Button>
+    </div>
+  );
+}
+
 export function NostrBindConsentDialog() {
   const isPreview = isNostrBindPreviewEnabled();
   const [payload, setPayload] = React.useState<NostrBindDeepLinkPayload | null>(
@@ -154,12 +228,15 @@ export function NostrBindConsentDialog() {
   const [hasCodeMismatch, setHasCodeMismatch] = React.useState(false);
   const [copyFailed, setCopyFailed] = React.useState(false);
   const [error, setError] = React.useState<string | null>(null);
+  const [isManualFallbackOpen, setIsManualFallbackOpen] = React.useState(false);
   const codeInputRefs = React.useRef<Array<HTMLInputElement | null>>([]);
   const codeShakeRef = React.useRef<HTMLDivElement | null>(null);
   const codeShakeAnimationRef = React.useRef<Animation | null>(null);
   const copiedTimerRef = React.useRef<ReturnType<typeof setTimeout> | null>(
     null,
   );
+  const autoSignAttemptRef = React.useRef<string | null>(null);
+  const activeSignAttemptRef = React.useRef<symbol | null>(null);
   const systemColorScheme = useSystemColorScheme();
   const shouldReduceMotion = useReducedMotion();
   const enteredVerificationCode = verificationCode.join("");
@@ -204,13 +281,17 @@ export function NostrBindConsentDialog() {
 
     const unlistenPromise = listenForNostrBindDeepLinks((nextPayload) => {
       clearCopiedState();
+      autoSignAttemptRef.current = null;
+      activeSignAttemptRef.current = null;
       setPayload(nextPayload);
       setIdentity(null);
+      setIsSigning(false);
       setSignedResponse(null);
       setVerificationCode(createEmptyVerificationCode());
       setHasCodeMismatch(false);
       setCopyFailed(false);
       setError(null);
+      setIsManualFallbackOpen(false);
       getIdentity()
         .then(setIdentity)
         .catch((error) => {
@@ -225,22 +306,19 @@ export function NostrBindConsentDialog() {
     };
   }, [clearCopiedState, isPreview]);
 
-  const isExpired = React.useMemo(() => {
-    if (!payload) {
-      return false;
-    }
-    const expiry = new Date(payload.expiresAt).getTime();
-    return Number.isNaN(expiry) || expiry <= Date.now();
-  }, [payload]);
+  const isExpired = payload !== null && isNostrBindRequestExpired(payload);
 
   const resetDialog = React.useCallback(() => {
     clearCopiedState();
+    autoSignAttemptRef.current = null;
+    activeSignAttemptRef.current = null;
     setPayload(null);
     setSignedResponse(null);
     setVerificationCode(createEmptyVerificationCode());
     setHasCodeMismatch(false);
     setCopyFailed(false);
     setError(null);
+    setIsManualFallbackOpen(false);
     setIdentity(null);
     setIsSigning(false);
   }, [clearCopiedState]);
@@ -297,6 +375,7 @@ export function NostrBindConsentDialog() {
     (index: number, value: string) => {
       const nextDigits = value.replace(/\D/g, "");
       const next = [...verificationCode];
+      autoSignAttemptRef.current = null;
 
       if (!nextDigits) {
         next[index] = "";
@@ -363,6 +442,7 @@ export function NostrBindConsentDialog() {
       }
 
       event.preventDefault();
+      autoSignAttemptRef.current = null;
       const next = normalizeVerificationCode(pastedCode);
       setVerificationCode(next);
       if (
@@ -402,6 +482,7 @@ export function NostrBindConsentDialog() {
 
       if (event.key === "Backspace") {
         event.preventDefault();
+        autoSignAttemptRef.current = null;
         const targetIndex = verificationCode[index]
           ? index
           : Math.max(index - 1, 0);
@@ -429,10 +510,10 @@ export function NostrBindConsentDialog() {
   );
 
   const handleSign = React.useCallback(async () => {
-    if (!payload) {
+    if (activeSignAttemptRef.current || !payload) {
       return;
     }
-    if (isExpired) {
+    if (isNostrBindRequestExpired(payload)) {
       setError(EXPIRED_LINK_MESSAGE);
       return;
     }
@@ -447,6 +528,8 @@ export function NostrBindConsentDialog() {
       return;
     }
 
+    const attempt = Symbol("nostr-bind-sign");
+    activeSignAttemptRef.current = attempt;
     setIsSigning(true);
     clearCopiedState();
     setError(null);
@@ -461,21 +544,35 @@ export function NostrBindConsentDialog() {
             origin: payload.origin,
             expiresAt: payload.expiresAt,
           });
+      if (activeSignAttemptRef.current !== attempt) {
+        return;
+      }
+
       setSignedResponse(signed);
       if (payload.returnMode === "browser_fragment_v1" && payload.callbackUrl) {
-        setError(
-          await returnSignedResponseToBrowser(payload.callbackUrl, signed),
+        const callbackError = await returnSignedResponseToBrowser(
+          payload.callbackUrl,
+          signed,
         );
+        if (activeSignAttemptRef.current !== attempt) {
+          return;
+        }
+        setError(callbackError);
+        setIsManualFallbackOpen(callbackError !== null);
       }
     } catch (error) {
-      setError(formatError(error) || "Failed to sign binding response.");
+      if (activeSignAttemptRef.current === attempt) {
+        setError(formatError(error) || "Failed to sign binding response.");
+      }
     } finally {
-      setIsSigning(false);
+      if (activeSignAttemptRef.current === attempt) {
+        activeSignAttemptRef.current = null;
+        setIsSigning(false);
+      }
     }
   }, [
     clearCopiedState,
     enteredVerificationCode,
-    isExpired,
     isPreview,
     isVerificationCodeComplete,
     isVerificationCodeValid,
@@ -484,6 +581,35 @@ export function NostrBindConsentDialog() {
     verificationCode,
   ]);
 
+  React.useEffect(() => {
+    if (
+      !payload ||
+      identity === null ||
+      isExpired ||
+      isSigning ||
+      signedResponse !== null ||
+      !isVerificationCodeValid
+    ) {
+      return;
+    }
+
+    const attemptKey = `${payload.challengeId}:${enteredVerificationCode}`;
+    if (autoSignAttemptRef.current === attemptKey) {
+      return;
+    }
+    autoSignAttemptRef.current = attemptKey;
+    void handleSign();
+  }, [
+    enteredVerificationCode,
+    handleSign,
+    identity,
+    isExpired,
+    isSigning,
+    isVerificationCodeValid,
+    payload,
+    signedResponse,
+  ]);
+
   const handleCopyAgain = React.useCallback(async () => {
     if (!signedResponse) {
       return;
@@ -548,7 +674,7 @@ export function NostrBindConsentDialog() {
                     id="nostr-bind-description"
                   >
                     {payload.returnMode === "browser_fragment_v1"
-                      ? "Buzz opened your browser to finish verification. If it did not open, copy the response below."
+                      ? "Buzz opened your browser to finish verification."
                       : "Copy the response below, then paste it into the Buzz website to finish verification."}
                   </DialogPrimitive.Description>
 
@@ -558,65 +684,50 @@ export function NostrBindConsentDialog() {
                     </p>
                   ) : null}
 
-                  <pre
-                    className="mt-10 max-h-56 w-full overflow-auto rounded-2xl border border-border/70 bg-muted/60 p-4 text-left shadow-xs"
-                    data-testid="nostr-bind-signed-response"
-                  >
-                    <code className="whitespace-pre-wrap break-all font-mono text-xs leading-5 text-foreground">
-                      {signedResponse}
-                    </code>
-                  </pre>
-
-                  {copyFailed ? (
-                    <p className="mt-4 w-full rounded-md border border-destructive/30 bg-destructive/10 px-3 py-2 text-left text-sm text-destructive">
-                      {COPY_FAILURE_MESSAGE}
-                    </p>
-                  ) : null}
+                  {payload.returnMode === "browser_fragment_v1" ? (
+                    <details
+                      className="group mt-10 w-full overflow-hidden rounded-2xl border border-border/70 bg-muted/30 text-left shadow-xs"
+                      data-testid="nostr-bind-manual-fallback"
+                      onToggle={(event) =>
+                        setIsManualFallbackOpen(event.currentTarget.open)
+                      }
+                      open={isManualFallbackOpen}
+                    >
+                      <summary className="flex cursor-pointer list-none items-center justify-between gap-4 px-4 py-3 text-sm font-medium transition-colors hover:bg-muted/40 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-ring [&::-webkit-details-marker]:hidden">
+                        <span>Pairing didn’t finish automatically?</span>
+                        <ChevronDown className="h-4 w-4 shrink-0 text-muted-foreground transition-transform duration-150 group-open:rotate-180" />
+                      </summary>
+                      <div className="space-y-4 border-t border-border/55 p-4">
+                        <p className="text-sm leading-6 text-muted-foreground">
+                          Copy this response and paste it into the pairing page.
+                        </p>
+                        <SignedResponseControls
+                          copyFailed={copyFailed}
+                          copyLabel={finishCopyButtonLabel}
+                          onCopy={handleCopyAgain}
+                          signedResponse={signedResponse}
+                        />
+                      </div>
+                    </details>
+                  ) : (
+                    <div className="mt-10 w-full">
+                      <SignedResponseControls
+                        copyFailed={copyFailed}
+                        copyLabel={finishCopyButtonLabel}
+                        onCopy={handleCopyAgain}
+                        signedResponse={signedResponse}
+                      />
+                    </div>
+                  )}
 
                   <div className="mt-8 flex w-full flex-col gap-3">
-                    <Button
-                      aria-label={finishCopyButtonLabel}
-                      className="h-10 w-full"
-                      data-testid="nostr-bind-copy-response"
-                      onClick={handleCopyAgain}
-                      type="button"
-                    >
-                      <span aria-live="polite" className="sr-only">
-                        {finishCopyButtonLabel}
-                      </span>
-                      <span
-                        aria-hidden="true"
-                        className="inline-grid h-5 place-items-center overflow-hidden"
-                      >
-                        <span
-                          className={cn(
-                            COPY_BUTTON_LABEL_CLASS,
-                            finishCopyButtonLabel === "Copy response"
-                              ? "translate-y-0 opacity-100"
-                              : "-translate-y-0.5 opacity-0",
-                          )}
-                        >
-                          Copy response
-                        </span>
-                        <span
-                          className={cn(
-                            COPY_BUTTON_LABEL_CLASS,
-                            finishCopyButtonLabel === "Copied"
-                              ? "translate-y-0 opacity-100"
-                              : "translate-y-0.5 opacity-0",
-                          )}
-                        >
-                          Copied
-                        </span>
-                      </span>
-                    </Button>
                     <Button
                       className="h-10 w-full text-muted-foreground hover:text-accent-foreground"
                       onClick={() => handleOpenChange(false)}
                       type="button"
                       variant="ghost"
                     >
-                      Close
+                      Continue
                     </Button>
                   </div>
                 </OnboardingSlideTransition>

desktop/src/testing/e2eBridge.ts

@@ -189,6 +189,10 @@ type E2eConfig = {
      *  Linux .deb install where Tauri's updater cannot swap the binary).
      *  Defaults to true for all existing tests. */
     autoUpdateSupported?: boolean;
+    /** Reject `plugin:opener|open_url` to exercise browser-return fallback UI. */
+    openerError?: string;
+    /** Delay binding signatures so specs can exercise request supersession. */
+    nostrBindSignDelayMs?: number;
     stallWebsocketSends?: boolean;
     userSearchDelayMs?: number;
     // NIP-IA gate inputs — see tests/helpers/bridge.ts:MockBridgeOptions for
@@ -8641,6 +8645,10 @@ export function maybeInstallE2eTauriMocks() {
           origin: string;
           verificationCode: string;
         };
+        const signDelayMs = activeConfig?.mock?.nostrBindSignDelayMs ?? 0;
+        if (signDelayMs > 0) {
+          await new Promise((resolve) => setTimeout(resolve, signDelayMs));
+        }
         const activeIdentity = identity ?? DEFAULT_MOCK_IDENTITY;
         return JSON.stringify({
           id: "e2e-signed-nostr-binding",
@@ -9654,6 +9662,9 @@ export function maybeInstallE2eTauriMocks() {
           payload as Parameters<typeof sendToMockSocket>[0],
         );
       case "plugin:opener|open_url":
+        if (activeConfig?.mock?.openerError) {
+          throw new Error(activeConfig.mock.openerError);
+        }
         openedExternalUrls.push(String((payload as { url: string | URL }).url));
         return null;
       case "get_e2e_opened_external_urls":

desktop/tests/e2e/nostr-bind.spec.ts

@@ -28,21 +28,7 @@ const VALID_REQUEST: NostrBindPayload = {
   version: "1",
 };
 
-async function openNostrBind(
-  page: Page,
-  payload: NostrBindPayload = VALID_REQUEST,
-) {
-  await installMockBridge(page);
-  await page.goto("/");
-  await page.waitForFunction(
-    () =>
-      typeof (
-        window as Window & {
-          __BUZZ_E2E_INVOKE_MOCK_COMMAND__?: unknown;
-        }
-      ).__BUZZ_E2E_INVOKE_MOCK_COMMAND__ === "function",
-  );
-
+async function emitNostrBind(page: Page, payload: NostrBindPayload) {
   await page.evaluate(async (nextPayload) => {
     const internals = (
       window as Window & {
@@ -62,7 +48,24 @@ async function openNostrBind(
       payload: nextPayload,
     });
   }, payload);
+}
 
+async function openNostrBind(
+  page: Page,
+  payload: NostrBindPayload = VALID_REQUEST,
+  mock?: Parameters<typeof installMockBridge>[1],
+) {
+  await installMockBridge(page, mock);
+  await page.goto("/");
+  await page.waitForFunction(
+    () =>
+      typeof (
+        window as Window & {
+          __BUZZ_E2E_INVOKE_MOCK_COMMAND__?: unknown;
+        }
+      ).__BUZZ_E2E_INVOKE_MOCK_COMMAND__ === "function",
+  );
+  await emitNostrBind(page, payload);
   await expect(page.getByTestId("nostr-bind-page")).toBeVisible();
 }
 
@@ -150,7 +153,7 @@ async function shakeCount(page: Page): Promise<number> {
   );
 }
 
-test("supports OTP entry, navigation, and paste without signing incomplete input", async ({
+test("supports OTP entry and navigation without signing incomplete input", async ({
   page,
 }) => {
   await openNostrBind(page);
@@ -174,42 +177,70 @@ test("supports OTP entry, navigation, and paste without signing incomplete input
   await expect(second).toHaveValue("");
   await expect(continueButton).toBeDisabled();
   await expect.poll(() => signCommandPayloads(page)).toEqual([]);
-
-  await pasteCode(first, VALID_REQUEST.verificationCode);
-  for (const [index, digit] of [...VALID_REQUEST.verificationCode].entries()) {
-    await expect(
-      page.getByTestId(`nostr-bind-code-digit-${index + 1}`),
-    ).toHaveValue(digit);
-  }
-  await expect(page.getByTestId("nostr-bind-code-digit-6")).toBeFocused();
-  await expect(continueButton).toBeEnabled();
 });
 
-test("locks a filled sixth slot and repeats mismatch feedback without signing", async ({
+test("auto-signs exactly once when the sixth correct digit is typed", async ({
   page,
 }) => {
+  await openNostrBind(page);
+
+  await page.getByTestId("nostr-bind-code-digit-1").click();
+  for (const digit of VALID_REQUEST.verificationCode) {
+    await page.keyboard.type(digit);
+  }
+
+  await expect(page.getByTestId("nostr-bind-finish-step")).toBeVisible();
+  await expect.poll(() => signCommandPayloads(page)).toHaveLength(1);
+  await page.waitForTimeout(100);
+  await expect.poll(() => signCommandPayloads(page)).toHaveLength(1);
+});
+
+test("discards a signature when a newer pairing request arrives", async ({
+  page,
+}) => {
+  await openNostrBind(page, VALID_REQUEST, { nostrBindSignDelayMs: 150 });
+  await pasteCode(
+    page.getByTestId("nostr-bind-code-digit-1"),
+    VALID_REQUEST.verificationCode,
+  );
+  await expect.poll(() => signCommandPayloads(page)).toHaveLength(1);
+
+  const nextRequest = {
+    ...VALID_REQUEST,
+    challengeId: "550e8400-e29b-41d4-a716-446655440001",
+    verificationCode: "654321",
+  };
+  await emitNostrBind(page, nextRequest);
+
+  await expect(page.getByTestId("nostr-bind-code-digit-1")).toHaveValue("");
+  await page.waitForTimeout(200);
+  await expect(page.getByTestId("nostr-bind-code-step")).toBeVisible();
+  await expect(page.getByTestId("nostr-bind-finish-step")).toBeHidden();
+
+  await pasteCode(
+    page.getByTestId("nostr-bind-code-digit-1"),
+    nextRequest.verificationCode,
+  );
+  await expect(page.getByTestId("nostr-bind-finish-step")).toBeVisible();
+  await expect.poll(() => signCommandPayloads(page)).toHaveLength(2);
+});
+
+test("repeats mismatch feedback without signing", async ({ page }) => {
   await installShakeCounter(page);
   await openNostrBind(page);
 
   const first = page.getByTestId("nostr-bind-code-digit-1");
-  const last = page.getByTestId("nostr-bind-code-digit-6");
   const continueButton = page.getByTestId("nostr-bind-sign-and-copy");
 
-  await pasteCode(first, VALID_REQUEST.verificationCode);
-  await last.press("9");
-  await expect(last).toHaveValue("6");
-  await expect(continueButton).toBeEnabled();
-  await expect.poll(() => shakeCount(page)).toBe(1);
-
   await pasteCode(first, "654321");
   await expect(page.getByRole("alert")).toHaveText(
     "That code doesn't match. Check the code and try again.",
   );
   await expect(continueButton).toBeDisabled();
-  await expect.poll(() => shakeCount(page)).toBe(2);
+  await expect.poll(() => shakeCount(page)).toBe(1);
 
   await pasteCode(first, "654321");
-  await expect.poll(() => shakeCount(page)).toBe(3);
+  await expect.poll(() => shakeCount(page)).toBe(2);
   await expect.poll(() => signCommandPayloads(page)).toEqual([]);
 });
 
@@ -263,7 +294,6 @@ test("signs a valid request, shows the response, and copies it", async ({
     VALID_REQUEST.verificationCode,
   );
 
-  await page.getByTestId("nostr-bind-sign-and-copy").click();
   await expect(page.getByTestId("nostr-bind-finish-step")).toBeVisible();
   const response = page.getByTestId("nostr-bind-signed-response");
   await expect(response).toContainText("e2e-signed-nostr-binding");
@@ -296,11 +326,16 @@ test("signs a valid request, shows the response, and copies it", async ({
       ),
     )
     .toBe(signedResponse);
+  await expect.poll(() => signCommandPayloads(page)).toHaveLength(1);
+
+  await page.getByRole("button", { name: "Continue" }).click();
+  await expect(page.getByTestId("nostr-bind-page")).toBeHidden();
 });
 
 test("returns a signed response in the callback fragment after consent", async ({
   page,
 }) => {
+  await installClipboardStub(page, false);
   await openNostrBind(page, {
     ...VALID_REQUEST,
     callbackUrl: "https://admin.example.com/buzz?source=bind#stale",
@@ -326,11 +361,38 @@ test("returns a signed response in the callback fragment after consent", async (
     page.getByTestId("nostr-bind-code-digit-1"),
     VALID_REQUEST.verificationCode,
   );
-  await page.getByTestId("nostr-bind-sign-and-copy").click();
+  await expect(page.getByTestId("nostr-bind-finish-step")).toBeVisible();
 
   await expect(
     page.getByRole("heading", { name: "Continue in your browser" }),
   ).toBeVisible();
+  const manualFallback = page.getByTestId("nostr-bind-manual-fallback");
+  await expect(manualFallback).not.toHaveAttribute("open", "");
+  await expect(page.getByTestId("nostr-bind-signed-response")).toBeHidden();
+  await expect(page.getByTestId("nostr-bind-copy-response")).toBeHidden();
+
+  const fallbackSummary = manualFallback.locator("summary");
+  await fallbackSummary.focus();
+  await fallbackSummary.press("Enter");
+  await expect(manualFallback).toHaveAttribute("open", "");
+  const signedResponse = page.getByTestId("nostr-bind-signed-response");
+  await expect(signedResponse).toContainText("e2e-signed-nostr-binding");
+  const copyResponse = page.getByTestId("nostr-bind-copy-response");
+  await expect(copyResponse).toBeVisible();
+  await copyResponse.click();
+  await expect
+    .poll(() =>
+      page.evaluate(
+        () =>
+          (
+            window as Window & {
+              __BUZZ_E2E_CLIPBOARD_TEXT__?: string;
+            }
+          ).__BUZZ_E2E_CLIPBOARD_TEXT__,
+      ),
+    )
+    .toBe(await signedResponse.textContent());
+
   const callback = await page.evaluate(() => {
     const command = (
       (
@@ -352,6 +414,36 @@ test("returns a signed response in the callback fragment after consent", async (
   expect(callbackUrl.hash).toMatch(/^#buzz_bind=v1\.[A-Za-z0-9_-]+$/);
 });
 
+test("opens the manual fallback when returning to the browser fails", async ({
+  page,
+}) => {
+  await openNostrBind(
+    page,
+    {
+      ...VALID_REQUEST,
+      callbackUrl: "https://admin.example.com/buzz",
+      returnMode: "browser_fragment_v1",
+    },
+    { openerError: "browser unavailable" },
+  );
+
+  await pasteCode(
+    page.getByTestId("nostr-bind-code-digit-1"),
+    VALID_REQUEST.verificationCode,
+  );
+
+  await expect(
+    page.getByText(
+      "Could not open the browser. Copy the response below to finish manually.",
+    ),
+  ).toBeVisible();
+  await expect(page.getByTestId("nostr-bind-manual-fallback")).toHaveAttribute(
+    "open",
+    "",
+  );
+  await expect(page.getByTestId("nostr-bind-copy-response")).toBeVisible();
+});
+
 test("keeps the signed response available when clipboard access fails", async ({
   page,
 }) => {
@@ -361,11 +453,13 @@ test("keeps the signed response available when clipboard access fails", async ({
     page.getByTestId("nostr-bind-code-digit-1"),
     VALID_REQUEST.verificationCode,
   );
-  await page.getByTestId("nostr-bind-sign-and-copy").click();
+  await expect(page.getByTestId("nostr-bind-finish-step")).toBeVisible();
 
   await page.getByTestId("nostr-bind-copy-response").click();
   await expect(
-    page.getByText("Buzz couldn't access the clipboard. Try again."),
+    page
+      .getByTestId("nostr-bind-manual-fallback-content")
+      .getByText("Buzz couldn't access the clipboard. Try again."),
   ).toBeVisible();
   await expect(page.getByTestId("nostr-bind-signed-response")).toContainText(
     "e2e-signed-nostr-binding",

desktop/tests/helpers/bridge.ts

@@ -206,6 +206,10 @@ type MockBridgeOptions = {
   /** Set to false to simulate a Linux .deb install where auto-update is not
    *  supported. Defaults to true. See e2eBridge mock.autoUpdateSupported. */
   autoUpdateSupported?: boolean;
+  /** Reject browser opener calls to exercise manual pairing fallback UI. */
+  openerError?: string;
+  /** Delay binding signatures so specs can exercise request supersession. */
+  nostrBindSignDelayMs?: number;
   stallWebsocketSends?: boolean;
   userSearchDelayMs?: number;
   // NIP-IA gate inputs — drive the archive-button gate matrix in