src/app/components/LogInBunker.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import {Capacitor} from "@capacitor/core"
   import {onMount, onDestroy} from "svelte"
   import type {Nip46ResponseWithResult} from "@welshman/signer"
   import {Nip46Broker} from "@welshman/signer"
@@ -103,10 +104,16 @@
     mode = "connect"
   }
 
+  const openSigner = () => {
+    controller.launchSigner()
+  }
+
   const selectBunker = () => {
     mode = "bunker"
   }
 
+  const isIos = Capacitor.getPlatform() === "ios"
+
   let mode: string = $state("bunker")
 
   $effect(() => {
@@ -138,6 +145,9 @@
       <BunkerUrl {controller} />
       <Button class="btn {$bunker ? 'btn-neutral' : 'btn-primary'}" onclick={selectConnect}
         >Log in with a QR code instead</Button>
+      {#if isIos}
+        <Button class="btn btn-neutral" onclick={openSigner}>Open in Signer</Button>
+      {/if}
     {/if}
   </ModalBody>
   <ModalFooter>

src/app/util/nip46.ts

@@ -1,4 +1,4 @@
-import {writable} from "svelte/store"
+import {get, writable} from "svelte/store"
 import type {Nip46ResponseWithResult} from "@welshman/signer"
 import {Nip46Broker} from "@welshman/signer"
 import {makeSecret} from "@welshman/util"
@@ -11,6 +11,22 @@ import {
 } from "@app/core/state"
 import {pushToast} from "@app/util/toast"
 
+const APP_SCHEME = "social.flotilla"
+
+const makeSignerCallbackUrl = (path: string) => `${APP_SCHEME}://x-callback-url/${path}`
+
+const makeSignerLaunchUrl = (nostrconnectUrl: string) => {
+  const params = new URLSearchParams({
+    method: "connect",
+    nostrconnect: nostrconnectUrl,
+    "x-source": APP_SCHEME,
+    "x-success": makeSignerCallbackUrl("authSuccess"),
+    "x-error": makeSignerCallbackUrl("authError"),
+  })
+
+  return `nostrsigner://x-callback-url/auth/nip46?${params.toString()}`
+}
+
 export class Nip46Controller {
   url = writable("")
   bunker = writable("")
@@ -54,6 +70,22 @@ export class Nip46Controller {
     }
   }
 
+  launchSigner() {
+    const nostrconnectUrl = get(this.url)
+    const signerUrl = nostrconnectUrl && makeSignerLaunchUrl(nostrconnectUrl)
+
+    if (!signerUrl) {
+      pushToast({
+        theme: "error",
+        message: "Unable to open signer app right now. Please try again.",
+      })
+
+      return
+    }
+
+    window.location.href = signerUrl
+  }
+
   stop() {
     this.broker.cleanup()
     this.abortController.abort()

src/routes/+layout.svelte

@@ -78,6 +78,21 @@
       return
     }
 
+    if (url.host === "x-callback-url") {
+      if (url.pathname === "/authError") {
+        const errorMessage = url.searchParams.get("errorMessage")
+
+        pushToast({
+          theme: "error",
+          message: errorMessage || "Signer authorization failed.",
+        })
+      }
+
+      if (["/authSuccess", "/authError"].includes(url.pathname)) {
+        return
+      }
+    }
+
     const target = `${url.pathname}${url.search}${url.hash}`
     goto(target, {replaceState: false, noScroll: false})
   })