refactor(canvas): host A2UI via gateway

apps/android/app/src/main/java/com/steipete/clawdis/node/NodeRuntime.kt

@@ -605,9 +605,17 @@ class NodeRuntime(context: Context) {
         BridgeSession.InvokeResult.ok("""{"format":"${snapshotParams.format.rawValue}","base64":"$base64"}""")
       }
       ClawdisCanvasA2UICommand.Reset.rawValue -> {
-        val ready = ensureA2uiReady()
+        val a2uiUrl = resolveA2uiHostUrl()
+          ?: return BridgeSession.InvokeResult.error(
+            code = "A2UI_HOST_NOT_CONFIGURED",
+            message = "A2UI_HOST_NOT_CONFIGURED: gateway did not advertise canvas host",
+          )
+        val ready = ensureA2uiReady(a2uiUrl)
         if (!ready) {
-          return BridgeSession.InvokeResult.error(code = "A2UI_NOT_READY", message = "A2UI not ready")
+          return BridgeSession.InvokeResult.error(
+            code = "A2UI_HOST_UNAVAILABLE",
+            message = "A2UI host not reachable",
+          )
         }
         val res = canvas.eval(a2uiResetJS)
         BridgeSession.InvokeResult.ok(res)
@@ -619,9 +627,17 @@ class NodeRuntime(context: Context) {
           } catch (err: Throwable) {
             return BridgeSession.InvokeResult.error(code = "INVALID_REQUEST", message = err.message ?: "invalid A2UI payload")
           }
-        val ready = ensureA2uiReady()
+        val a2uiUrl = resolveA2uiHostUrl()
+          ?: return BridgeSession.InvokeResult.error(
+            code = "A2UI_HOST_NOT_CONFIGURED",
+            message = "A2UI_HOST_NOT_CONFIGURED: gateway did not advertise canvas host",
+          )
+        val ready = ensureA2uiReady(a2uiUrl)
         if (!ready) {
-          return BridgeSession.InvokeResult.error(code = "A2UI_NOT_READY", message = "A2UI not ready")
+          return BridgeSession.InvokeResult.error(
+            code = "A2UI_HOST_UNAVAILABLE",
+            message = "A2UI host not reachable",
+          )
         }
         val js = a2uiApplyMessagesJS(messages)
         val res = canvas.eval(js)
@@ -707,7 +723,14 @@ class NodeRuntime(context: Context) {
     return code to "$code: $message"
   }
 
-  private suspend fun ensureA2uiReady(): Boolean {
+  private fun resolveA2uiHostUrl(): String? {
+    val raw = session.currentCanvasHostUrl()?.trim().orEmpty()
+    if (raw.isBlank()) return null
+    val base = raw.trimEnd('/')
+    return "${base}/__clawdis__/a2ui/"
+  }
+
+  private suspend fun ensureA2uiReady(a2uiUrl: String): Boolean {
     try {
       val already = canvas.eval(a2uiReadyCheckJS)
       if (already == "true") return true
@@ -715,8 +738,7 @@ class NodeRuntime(context: Context) {
       // ignore
     }
 
-    // Ensure the default canvas scaffold is loaded; A2UI is now hosted there.
+    canvas.navigate(a2uiUrl)
-    canvas.navigate("")
     repeat(50) {
       try {
         val ready = canvas.eval(a2uiReadyCheckJS)

apps/android/app/src/main/java/com/steipete/clawdis/node/bridge/BridgeSession.kt

@@ -61,6 +61,7 @@ class BridgeSession(
   private val json = Json { ignoreUnknownKeys = true }
   private val writeLock = Mutex()
   private val pending = ConcurrentHashMap<String, CompletableDeferred<RpcResponse>>()
+  @Volatile private var canvasHostUrl: String? = null
 
   private var desired: Pair<BridgeEndpoint, Hello>? = null
   private var job: Job? = null
@@ -77,10 +78,13 @@ class BridgeSession(
     scope.launch(Dispatchers.IO) {
       job?.cancelAndJoin()
       job = null
+      canvasHostUrl = null
       onDisconnected("Offline")
     }
   }
 
+  fun currentCanvasHostUrl(): String? = canvasHostUrl
+
   suspend fun sendEvent(event: String, payloadJson: String?) {
     val conn = currentConnection ?: return
     conn.sendJson(
@@ -209,6 +213,7 @@ class BridgeSession(
         when (first["type"].asStringOrNull()) {
           "hello-ok" -> {
             val name = first["serverName"].asStringOrNull() ?: "Bridge"
+            canvasHostUrl = first["canvasHostUrl"].asStringOrNull()?.trim()?.ifEmpty { null }
             onConnected(name, conn.remoteAddress)
           }
           "error" -> {

apps/android/app/src/test/java/com/steipete/clawdis/node/bridge/BridgeSessionTest.kt

@@ -46,7 +46,7 @@ class BridgeSessionTest {
 
             val hello = reader.readLine()
             assertTrue(hello.contains("\"type\":\"hello\""))
-            writer.write("""{"type":"hello-ok","serverName":"Test Bridge"}""")
+            writer.write("""{"type":"hello-ok","serverName":"Test Bridge","canvasHostUrl":"http://127.0.0.1:18793"}""")
             writer.write("\n")
             writer.flush()
 
@@ -77,6 +77,7 @@ class BridgeSessionTest {
     )
 
     connected.await()
+    assertEquals("http://127.0.0.1:18793", session.currentCanvasHostUrl())
     val payload = session.request(method = "health", paramsJson = null)
     assertEquals("""{"value":123}""", payload)
     server.await()

apps/ios/Sources/Bridge/BridgeSession.swift

@@ -25,6 +25,11 @@ actor BridgeSession {
     private var serverEventSubscribers: [UUID: AsyncStream<BridgeEventFrame>.Continuation] = [:]
 
     private(set) var state: State = .idle
+    private var canvasHostUrl: String?
+
+    func currentCanvasHostUrl() -> String? {
+        self.canvasHostUrl
+    }
 
     func currentRemoteAddress() -> String? {
         guard let endpoint = self.connection?.currentPath?.remoteEndpoint else { return nil }
@@ -101,6 +106,7 @@ actor BridgeSession {
         if base.type == "hello-ok" {
             let ok = try self.decoder.decode(BridgeHelloOk.self, from: data)
             self.state = .connected(serverName: ok.serverName)
+            self.canvasHostUrl = ok.canvasHostUrl?.trimmingCharacters(in: .whitespacesAndNewlines)
             await onConnected?(ok.serverName)
         } else if base.type == "error" {
             let err = try self.decoder.decode(BridgeErrorFrame.self, from: data)
@@ -210,6 +216,7 @@ actor BridgeSession {
         self.connection = nil
         self.queue = nil
         self.buffer = Data()
+        self.canvasHostUrl = nil
 
         let pending = self.pendingRPC.values
         self.pendingRPC.removeAll()

apps/ios/Sources/Model/NodeAppModel.swift

@@ -143,6 +143,13 @@ final class NodeAppModel {
         }
     }
 
+    private func resolveA2UIHostURL() async -> String? {
+        guard let raw = await self.bridge.currentCanvasHostUrl() else { return nil }
+        let trimmed = raw.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty, let base = URL(string: trimmed) else { return nil }
+        return base.appendingPathComponent("__clawdis__/a2ui/").absoluteString
+    }
+
     func setScenePhase(_ phase: ScenePhase) {
         switch phase {
         case .background:
@@ -436,12 +443,22 @@ final class NodeAppModel {
                 return BridgeInvokeResponse(id: req.id, ok: true, payloadJSON: payload)
 
             case ClawdisCanvasA2UICommand.reset.rawValue:
-                self.screen.showDefaultCanvas()
+                guard let a2uiUrl = await self.resolveA2UIHostURL() else {
+                    return BridgeInvokeResponse(
+                        id: req.id,
+                        ok: false,
+                        error: ClawdisNodeError(
+                            code: .unavailable,
+                            message: "A2UI_HOST_NOT_CONFIGURED: gateway did not advertise canvas host"))
+                }
+                self.screen.navigate(to: a2uiUrl)
                 if await !self.screen.waitForA2UIReady(timeoutMs: 5000) {
                     return BridgeInvokeResponse(
                         id: req.id,
                         ok: false,
-                        error: ClawdisNodeError(code: .unavailable, message: "A2UI not ready"))
+                        error: ClawdisNodeError(
+                            code: .unavailable,
+                            message: "A2UI_HOST_UNAVAILABLE: A2UI host not reachable"))
                 }
 
                 let json = try await self.screen.eval(javaScript: """
@@ -468,12 +485,22 @@ final class NodeAppModel {
                     }
                 }
 
-                self.screen.showDefaultCanvas()
+                guard let a2uiUrl = await self.resolveA2UIHostURL() else {
+                    return BridgeInvokeResponse(
+                        id: req.id,
+                        ok: false,
+                        error: ClawdisNodeError(
+                            code: .unavailable,
+                            message: "A2UI_HOST_NOT_CONFIGURED: gateway did not advertise canvas host"))
+                }
+                self.screen.navigate(to: a2uiUrl)
                 if await !self.screen.waitForA2UIReady(timeoutMs: 5000) {
                     return BridgeInvokeResponse(
                         id: req.id,
                         ok: false,
-                        error: ClawdisNodeError(code: .unavailable, message: "A2UI not ready"))
+                        error: ClawdisNodeError(
+                            code: .unavailable,
+                            message: "A2UI_HOST_UNAVAILABLE: A2UI host not reachable"))
                 }
 
                 let messagesJSON = try ClawdisCanvasA2UIJSONL.encodeMessagesJSONArray(messages)

apps/ios/Sources/Screen/ScreenController.swift

@@ -199,11 +199,6 @@ final class ScreenController {
         name: "scaffold",
         ext: "html",
         subdirectory: "CanvasScaffold")
-    private static let a2uiIndexURL: URL? = ScreenController.bundledResourceURL(
-        name: "index",
-        ext: "html",
-        subdirectory: "CanvasA2UI")
-
     func isTrustedCanvasUIURL(_ url: URL) -> Bool {
         guard url.isFileURL else { return false }
         let std = url.standardizedFileURL
@@ -212,11 +207,6 @@ final class ScreenController {
         {
             return true
         }
-        if let expected = Self.a2uiIndexURL,
-           std == expected.standardizedFileURL
-        {
-            return true
-        }
         return false
     }
 

apps/macos/Sources/Clawdis/CanvasManager.swift

@@ -1,6 +1,5 @@
 import AppKit
 import ClawdisIPC
-import ClawdisKit
 import Foundation
 import OSLog
 
@@ -192,12 +191,12 @@ final class CanvasManager {
         if path.hasPrefix("/") { path.removeFirst() }
         path = path.removingPercentEncoding ?? path
 
-        // Root special-case: built-in shell page when no index exists.
+        // Root special-case: built-in scaffold page when no index exists.
         if path.isEmpty {
             let a = sessionDir.appendingPathComponent("index.html", isDirectory: false)
             let b = sessionDir.appendingPathComponent("index.htm", isDirectory: false)
             if fm.fileExists(atPath: a.path) || fm.fileExists(atPath: b.path) { return .ok }
-            return Self.hasBundledA2UIShell() ? .a2uiShell : .welcome
+            return .welcome
         }
 
         // Direct file or directory.
@@ -229,11 +228,5 @@ final class CanvasManager {
         return fm.fileExists(atPath: b.path)
     }
 
-    private static func hasBundledA2UIShell() -> Bool {
+    // no bundled A2UI shell; scaffold fallback is purely visual
-        let bundle = ClawdisKitResources.bundle
-        if bundle.url(forResource: "index", withExtension: "html", subdirectory: "CanvasA2UI") != nil {
-            return true
-        }
-        return bundle.url(forResource: "index", withExtension: "html") != nil
-    }
 }

apps/macos/Sources/Clawdis/CanvasSchemeHandler.swift

@@ -8,8 +8,6 @@ private let canvasLogger = Logger(subsystem: "com.steipete.clawdis", category: "
 final class CanvasSchemeHandler: NSObject, WKURLSchemeHandler {
     private let root: URL
 
-    private static let builtinPrefix = "__clawdis__/a2ui"
-
     init(root: URL) {
         self.root = root
     }
@@ -67,10 +65,6 @@ final class CanvasSchemeHandler: NSObject, WKURLSchemeHandler {
         if path.hasPrefix("/") { path.removeFirst() }
         path = path.removingPercentEncoding ?? path
 
-        if let builtin = self.builtinResponse(requestPath: path) {
-            return builtin
-        }
-
         // Special-case: welcome page when root index is missing.
         if path.isEmpty {
             let indexA = sessionRoot.appendingPathComponent("index.html", isDirectory: false)
@@ -78,7 +72,7 @@ final class CanvasSchemeHandler: NSObject, WKURLSchemeHandler {
             if !FileManager.default.fileExists(atPath: indexA.path),
                !FileManager.default.fileExists(atPath: indexB.path)
             {
-                return self.a2uiShellPage(sessionRoot: sessionRoot)
+                return self.scaffoldPage(sessionRoot: sessionRoot)
             }
         }
 
@@ -204,7 +198,7 @@ final class CanvasSchemeHandler: NSObject, WKURLSchemeHandler {
         return self.html(body, title: "Canvas")
     }
 
-    private func a2uiShellPage(sessionRoot: URL) -> CanvasResponse {
+    private func scaffoldPage(sessionRoot: URL) -> CanvasResponse {
         // Default Canvas UX: when no index exists, show the built-in scaffold page.
         if let data = self.loadBundledResourceData(relativePath: "CanvasScaffold/scaffold.html") {
             return CanvasResponse(mime: "text/html", data: data)
@@ -214,35 +208,6 @@ final class CanvasSchemeHandler: NSObject, WKURLSchemeHandler {
         return self.welcomePage(sessionRoot: sessionRoot)
     }
 
-    private func builtinResponse(requestPath: String) -> CanvasResponse? {
-        let trimmed = requestPath.trimmingCharacters(in: .whitespacesAndNewlines)
-        guard !trimmed.isEmpty else { return nil }
-
-        guard trimmed == Self.builtinPrefix
-            || trimmed == Self.builtinPrefix + "/"
-            || trimmed.hasPrefix(Self.builtinPrefix + "/")
-        else { return nil }
-
-        let relative = if trimmed == Self.builtinPrefix || trimmed == Self.builtinPrefix + "/" {
-            "index.html"
-        } else {
-            String(trimmed.dropFirst((Self.builtinPrefix + "/").count))
-        }
-
-        if relative.isEmpty { return self.html("Not Found", title: "Canvas: 404") }
-        if relative.contains("..") || relative.contains("\\") {
-            return self.html("Forbidden", title: "Canvas: 403")
-        }
-
-        guard let data = self.loadBundledResourceData(relativePath: "CanvasA2UI/\(relative)") else {
-            return self.html("Not Found", title: "Canvas: 404")
-        }
-
-        let ext = (relative as NSString).pathExtension
-        let mime = CanvasScheme.mimeType(forExtension: ext)
-        return CanvasResponse(mime: mime, data: data)
-    }
-
     private func loadBundledResourceData(relativePath: String) -> Data? {
         let trimmed = relativePath.trimmingCharacters(in: .whitespacesAndNewlines)
         guard !trimmed.isEmpty else { return nil }

apps/macos/Sources/Clawdis/CanvasWindow.swift

@@ -162,10 +162,7 @@ final class CanvasWindowController: NSWindowController, WKNavigationDelegate, NS
                 // Only auto-reload when we are showing local canvas content.
                 guard webView.url?.scheme == CanvasScheme.scheme else { return }
 
-                // Avoid reloading the built-in A2UI shell due to filesystem noise (it does not depend on session
-                // files).
                 let path = webView.url?.path ?? ""
-                if path.hasPrefix("/__clawdis__/a2ui") { return }
                 if path == "/" || path.isEmpty {
                     let indexA = sessionDir.appendingPathComponent("index.html", isDirectory: false)
                     let indexB = sessionDir.appendingPathComponent("index.htm", isDirectory: false)
@@ -608,9 +605,14 @@ private final class CanvasA2UIActionMessageHandler: NSObject, WKScriptMessageHan
         guard message.name == Self.messageName else { return }
 
         // Only accept actions from local Canvas content (not arbitrary web pages).
-        guard let webView = message.webView,
+        guard let webView = message.webView, let url = webView.url else { return }
-              webView.url?.scheme == CanvasScheme.scheme
+        if url.scheme == CanvasScheme.scheme {
-        else { return }
+            // ok
+        } else if Self.isLocalNetworkCanvasURL(url) {
+            // ok
+        } else {
+            return
+        }
 
         let body: [String: Any] = {
             if let dict = message.body as? [String: Any] { return dict }
@@ -693,6 +695,43 @@ private final class CanvasA2UIActionMessageHandler: NSObject, WKScriptMessageHan
         }
     }
 
+    private static func isLocalNetworkCanvasURL(_ url: URL) -> Bool {
+        guard let scheme = url.scheme?.lowercased(), scheme == "http" || scheme == "https" else {
+            return false
+        }
+        guard let host = url.host?.trimmingCharacters(in: .whitespacesAndNewlines), !host.isEmpty else {
+            return false
+        }
+        if host == "localhost" { return true }
+        if host.hasSuffix(".local") { return true }
+        if host.hasSuffix(".ts.net") { return true }
+        if host.hasSuffix(".tailscale.net") { return true }
+        if !host.contains("."), !host.contains(":") { return true }
+        if let ipv4 = Self.parseIPv4(host) {
+            return Self.isLocalNetworkIPv4(ipv4)
+        }
+        return false
+    }
+
+    private static func parseIPv4(_ host: String) -> (UInt8, UInt8, UInt8, UInt8)? {
+        let parts = host.split(separator: ".", omittingEmptySubsequences: false)
+        guard parts.count == 4 else { return nil }
+        let bytes: [UInt8] = parts.compactMap { UInt8($0) }
+        guard bytes.count == 4 else { return nil }
+        return (bytes[0], bytes[1], bytes[2], bytes[3])
+    }
+
+    private static func isLocalNetworkIPv4(_ ip: (UInt8, UInt8, UInt8, UInt8)) -> Bool {
+        let (a, b, _, _) = ip
+        if a == 10 { return true }
+        if a == 172, (16...31).contains(Int(b)) { return true }
+        if a == 192, b == 168 { return true }
+        if a == 127 { return true }
+        if a == 169, b == 254 { return true }
+        if a == 100, (64...127).contains(Int(b)) { return true }
+        return false
+    }
+
     // Formatting helpers live in ClawdisKit (`ClawdisCanvasA2UIAction`).
 }
 

apps/macos/Sources/Clawdis/GatewayConnection.swift

@@ -172,6 +172,12 @@ actor GatewayConnection {
         self.lastSnapshot = nil
     }
 
+    func canvasHostUrl() async -> String? {
+        guard let snapshot = self.lastSnapshot else { return nil }
+        let trimmed = snapshot.canvashosturl?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
+        return trimmed.isEmpty ? nil : trimmed
+    }
+
     func subscribe(bufferingNewest: Int = 100) -> AsyncStream<GatewayPush> {
         let id = UUID()
         let snapshot = self.lastSnapshot

apps/macos/Sources/Clawdis/NodeMode/MacNodeRuntime.swift

@@ -6,7 +6,6 @@ import Foundation
 actor MacNodeRuntime {
     private let cameraCapture = CameraCaptureService()
     @MainActor private let screenRecorder = ScreenRecordService()
-    private static let a2uiShellPath = "/__clawdis__/a2ui/"
 
     // swiftlint:disable:next function_body_length
     func handleInvoke(_ req: BridgeInvokeRequest) async -> BridgeInvokeResponse {
@@ -248,15 +247,27 @@ actor MacNodeRuntime {
 
     private func ensureA2UIHost() async throws {
         if await self.isA2UIReady() { return }
+        guard let a2uiUrl = await self.resolveA2UIHostUrl() else {
+            throw NSError(domain: "Canvas", code: 30, userInfo: [
+                NSLocalizedDescriptionKey: "A2UI_HOST_NOT_CONFIGURED: gateway did not advertise canvas host",
+            ])
+        }
         _ = try await MainActor.run {
-            try CanvasManager.shared.show(sessionKey: "main", path: Self.a2uiShellPath)
+            try CanvasManager.shared.show(sessionKey: "main", path: a2uiUrl)
         }
         if await self.isA2UIReady(poll: true) { return }
         throw NSError(domain: "Canvas", code: 31, userInfo: [
-            NSLocalizedDescriptionKey: "A2UI not ready",
+            NSLocalizedDescriptionKey: "A2UI_HOST_UNAVAILABLE: A2UI host not reachable",
         ])
     }
 
+    private func resolveA2UIHostUrl() async -> String? {
+        guard let raw = await GatewayConnection.shared.canvasHostUrl() else { return nil }
+        let trimmed = raw.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty, let baseUrl = URL(string: trimmed) else { return nil }
+        return baseUrl.appendingPathComponent("__clawdis__/a2ui/").absoluteString
+    }
+
     private func isA2UIReady(poll: Bool = false) async -> Bool {
         let deadline = poll ? Date().addingTimeInterval(6.0) : Date()
         while true {

apps/macos/Sources/ClawdisIPC/IPC.swift

@@ -66,9 +66,7 @@ public enum CanvasShowStatus: String, Codable, Sendable {
     case ok
     /// Local canvas target did not resolve to a file (404 page).
     case notFound
-    /// Local canvas root ("/") has no index, so the built-in A2UI shell is shown.
+    /// Local scaffold fallback (e.g., no index.html present).
-    case a2uiShell
-    /// Legacy fallback when the built-in shell isn't available (dev misconfiguration).
     case welcome
 }
 

apps/macos/Sources/ClawdisProtocol/GatewayModels.swift

@@ -53,6 +53,7 @@ public struct HelloOk: Codable {
     public let server: [String: AnyCodable]
     public let features: [String: AnyCodable]
     public let snapshot: Snapshot
+    public let canvashosturl: String?
     public let policy: [String: AnyCodable]
 
     public init(
@@ -61,6 +62,7 @@ public struct HelloOk: Codable {
         server: [String: AnyCodable],
         features: [String: AnyCodable],
         snapshot: Snapshot,
+        canvashosturl: String?,
         policy: [String: AnyCodable]
     ) {
         self.type = type
@@ -68,6 +70,7 @@ public struct HelloOk: Codable {
         self.server = server
         self.features = features
         self.snapshot = snapshot
+        self.canvashosturl = canvashosturl
         self.policy = policy
     }
     private enum CodingKeys: String, CodingKey {
@@ -76,6 +79,7 @@ public struct HelloOk: Codable {
         case server
         case features
         case snapshot
+        case canvashosturl = "canvasHostUrl"
         case policy
     }
 }

apps/shared/ClawdisKit/Sources/ClawdisKit/BridgeFrames.swift

@@ -99,10 +99,12 @@ public struct BridgeHello: Codable, Sendable {
 public struct BridgeHelloOk: Codable, Sendable {
     public let type: String
     public let serverName: String
+    public let canvasHostUrl: String?
 
-    public init(type: String = "hello-ok", serverName: String) {
+    public init(type: String = "hello-ok", serverName: String, canvasHostUrl: String? = nil) {
         self.type = type
         self.serverName = serverName
+        self.canvasHostUrl = canvasHostUrl
     }
 }
 

apps/shared/ClawdisKit/Sources/ClawdisKit/Resources/CanvasScaffold/scaffold.html

@@ -85,16 +85,6 @@
         pointer-events: none;
         z-index: 3;
       }
-      #clawdis-a2ui-wrap {
-        position: fixed;
-        inset: 0;
-        display: none;
-        z-index: 2;
-      }
-      #clawdis-a2ui-wrap clawdis-a2ui-host {
-        display: block;
-        height: 100%;
-      }
       #clawdis-status .card {
         text-align: center;
         padding: 16px 18px;
@@ -126,9 +116,6 @@
         <div class="subtitle" id="clawdis-status-subtitle">Waiting for agent</div>
       </div>
     </div>
-    <div id="clawdis-a2ui-wrap">
-      <clawdis-a2ui-host></clawdis-a2ui-host>
-    </div>
     <script>
       (() => {
         const canvas = document.getElementById('clawdis-canvas');
@@ -170,92 +157,6 @@
         };
       })();
 
-      (() => {
-        const wrap = document.getElementById('clawdis-a2ui-wrap');
-        if (!wrap) return;
-
-        const candidates = [
-          // iOS (SwiftPM resources flattened)
-          "a2ui.bundle.js",
-          // Android (assets keep directory structure)
-          "../CanvasA2UI/a2ui.bundle.js",
-          "CanvasA2UI/a2ui.bundle.js",
-        ];
-
-        const loadScript = (src) =>
-          new Promise((resolve, reject) => {
-            const el = document.createElement("script");
-            el.src = src;
-            el.async = true;
-            el.onload = () => resolve();
-            el.onerror = () => reject(new Error(`failed to load ${src}`));
-            document.head.appendChild(el);
-          });
-
-        const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
-
-        const installVisibilityHooks = () => {
-          const api = globalThis.clawdisA2UI;
-          if (!api || typeof api.applyMessages !== "function") return false;
-          if (globalThis.__clawdisA2UIVisibilityHooksInstalled) return true;
-          globalThis.__clawdisA2UIVisibilityHooksInstalled = true;
-
-          const show = () => { wrap.style.display = "block"; };
-          const hide = () => { wrap.style.display = "none"; };
-
-          const sync = () => {
-            try {
-              const surfaces =
-                typeof api.getSurfaces === "function" ? api.getSurfaces() : [];
-              if (Array.isArray(surfaces) && surfaces.length > 0) show();
-              else hide();
-            } catch {
-              hide();
-            }
-          };
-
-          const origApply = api.applyMessages.bind(api);
-          api.applyMessages = (messages) => {
-            const res = origApply(messages);
-            sync();
-            return res;
-          };
-          const origReset = api.reset.bind(api);
-          api.reset = () => {
-            const res = origReset();
-            hide();
-            return res;
-          };
-
-          hide();
-          return true;
-        };
-
-        (async () => {
-          if (globalThis.clawdisA2UI) {
-            installVisibilityHooks();
-            return;
-          }
-
-          let loaded = false;
-          for (const src of candidates) {
-            try {
-              await loadScript(src);
-              loaded = true;
-              break;
-            } catch {
-              // try next
-            }
-          }
-          if (!loaded) return;
-
-          // Wait for custom element upgrade + connectedCallback to publish globalThis.clawdisA2UI.
-          for (let i = 0; i < 60; i += 1) {
-            if (installVisibilityHooks()) return;
-            await sleep(50);
-          }
-        })().catch(() => {});
-      })();
     </script>
   </body>
 </html>

apps/shared/ClawdisKit/Tests/ClawdisKitTests/CanvasA2UIActionTests.swift

@@ -28,40 +28,4 @@ import Testing
         #expect(msg.contains("instance=ipad16_6 ctx={\"city\":\"Vienna\"}"))
         #expect(msg.hasSuffix(" default=update_canvas"))
     }
-
-    @Test func a2uiBundleSupportsAndroidBridgeFallback() throws {
-        guard let url = ClawdisKitResources.bundle.url(forResource: "a2ui.bundle", withExtension: "js")
-        else {
-            throw NSError(domain: "Tests", code: 1, userInfo: [
-                NSLocalizedDescriptionKey: "Missing resource a2ui.bundle.js",
-            ])
-        }
-        let js = try String(contentsOf: url, encoding: .utf8)
-        #expect(js.contains("clawdisCanvasA2UIAction"))
-        #expect(js.contains("globalThis.clawdisCanvasA2UIAction"))
-    }
-
-    @Test func a2uiBundleWrapsDynamicCssValues() throws {
-        guard let url = ClawdisKitResources.bundle.url(forResource: "a2ui.bundle", withExtension: "js")
-        else {
-            throw NSError(domain: "Tests", code: 1, userInfo: [
-                NSLocalizedDescriptionKey: "Missing resource a2ui.bundle.js",
-            ])
-        }
-        let js = try String(contentsOf: url, encoding: .utf8)
-        #expect(js.contains("blur(${r(statusBlur)})"))
-        #expect(js.contains("box-shadow: ${r(statusShadow)}"))
-    }
-
-    @Test func a2uiBundleStylesModalBackdrop() throws {
-        guard let url = ClawdisKitResources.bundle.url(forResource: "a2ui.bundle", withExtension: "js")
-        else {
-            throw NSError(domain: "Tests", code: 1, userInfo: [
-                NSLocalizedDescriptionKey: "Missing resource a2ui.bundle.js",
-            ])
-        }
-        let js = try String(contentsOf: url, encoding: .utf8)
-        #expect(js.contains("::backdrop"))
-        #expect(js.contains("backdrop-filter: blur(6px)"))
-    }
 }

apps/shared/ClawdisKit/Tools/CanvasA2UI/bootstrap.js

@@ -8,14 +8,17 @@ import { themeContext } from "@clawdis/a2ui-theme-context";
 
 const modalStyles = css`
   dialog {
+    position: fixed;
+    inset: 0;
+    width: 100%;
+    height: 100%;
+    margin: 0;
     padding: 24px;
     border: none;
-    background: none;
+    background: rgba(5, 8, 16, 0.65);
-    display: flex;
+    backdrop-filter: blur(6px);
-    align-items: center;
+    display: grid;
-    justify-content: center;
+    place-items: center;
-    max-width: calc(100vw - 32px);
-    max-height: calc(100vh - 32px);
   }
 
   dialog::backdrop {

apps/shared/ClawdisKit/Tools/CanvasA2UI/rolldown.config.mjs

@@ -5,7 +5,14 @@ import { defineConfig } from "rolldown";
 const here = path.dirname(fileURLToPath(import.meta.url));
 const repoRoot = path.resolve(here, "../../../../..");
 const fromHere = (p) => path.resolve(here, p);
-const outputFile = path.resolve(here, "../../Sources/ClawdisKit/Resources/CanvasA2UI/a2ui.bundle.js");
+const outputFile = path.resolve(
+  here,
+  "../../../../..",
+  "src",
+  "canvas-host",
+  "a2ui",
+  "a2ui.bundle.js",
+);
 
 const a2uiLitDist = path.resolve(repoRoot, "vendor/a2ui/renderers/lit/dist/src");
 const a2uiThemeContext = path.resolve(a2uiLitDist, "0.8/ui/context/theme.js");

biome.json

@@ -5,6 +5,11 @@
 		"indentWidth": 2,
 		"indentStyle": "space"
 	},
+	"files": {
+		"includes": [
+			"src/**/*.ts"
+		]
+	},
 	"linter": {
 		"enabled": true,
 		"rules": {

package.json

@@ -10,7 +10,7 @@
   "scripts": {
     "dev": "tsx src/index.ts",
     "docs:list": "tsx scripts/docs-list.ts",
-    "build": "tsc -p tsconfig.json",
+    "build": "pnpm canvas:a2ui:bundle && tsc -p tsconfig.json && tsx scripts/canvas-a2ui-copy.ts",
     "ui:install": "pnpm -C ui install",
     "ui:dev": "pnpm -C ui dev",
     "ui:build": "pnpm -C ui build",

scripts/canvas-a2ui-copy.ts

@@ -0,0 +1,19 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
+const srcDir = path.join(repoRoot, "src", "canvas-host", "a2ui");
+const outDir = path.join(repoRoot, "dist", "canvas-host", "a2ui");
+
+async function main() {
+  await fs.stat(path.join(srcDir, "index.html"));
+  await fs.stat(path.join(srcDir, "a2ui.bundle.js"));
+  await fs.mkdir(path.dirname(outDir), { recursive: true });
+  await fs.cp(srcDir, outDir, { recursive: true });
+}
+
+main().catch((err) => {
+  console.error(String(err));
+  process.exit(1);
+});

scripts/package-mac-app.sh

@@ -156,6 +156,10 @@ if [[ "${SKIP_GATEWAY_PACKAGE:-0}" != "1" ]]; then
     --define "__CLAWDIS_VERSION__=\\\"$PKG_VERSION\\\""
   chmod +x "$CLI_OUT"
 
+  echo "🎨 Copying gateway A2UI host assets"
+  rm -rf "$RELAY_DIR/a2ui"
+  cp -R "$ROOT_DIR/src/canvas-host/a2ui" "$RELAY_DIR/a2ui"
+
   echo "📄 Writing embedded runtime package.json (Pi compatibility)"
   cat > "$RELAY_DIR/package.json" <<JSON
 {

scripts/restart-mac.sh

@@ -52,7 +52,7 @@ log "==> Killing existing Clawdis instances"
 kill_all_clawdis
 stop_launch_agent
 
-# Bundle built-in Canvas A2UI shell (single-file JS, shipped in the app bundle).
+# Bundle Gateway-hosted Canvas A2UI assets.
 run_step "bundle canvas a2ui" bash -lc "cd '${ROOT_DIR}' && pnpm canvas:a2ui:bundle"
 
 # 2) Rebuild into the same path the packager consumes (.build).

src/canvas-host/a2ui/index.html

@@ -3,7 +3,7 @@
   <head>
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
-    <title>Canvas</title>
+    <title>Clawdis Canvas</title>
     <style>
       :root { color-scheme: light dark; }
       html, body { height: 100%; margin: 0; }

src/canvas-host/server.test.ts

@@ -94,4 +94,36 @@ describe("canvas host", () => {
       await fs.rm(dir, { recursive: true, force: true });
     }
   });
+
+  it("serves the gateway-hosted A2UI scaffold", async () => {
+    const dir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdis-canvas-"));
+
+    const server = await startCanvasHost({
+      runtime: defaultRuntime,
+      rootDir: dir,
+      port: 0,
+      listenHost: "127.0.0.1",
+      allowInTests: true,
+    });
+
+    try {
+      const res = await fetch(
+        `http://127.0.0.1:${server.port}/__clawdis__/a2ui/`,
+      );
+      const html = await res.text();
+      expect(res.status).toBe(200);
+      expect(html).toContain("clawdis-a2ui-host");
+      expect(html).toContain("clawdisCanvasA2UIAction");
+
+      const bundleRes = await fetch(
+        `http://127.0.0.1:${server.port}/__clawdis__/a2ui/a2ui.bundle.js`,
+      );
+      const js = await bundleRes.text();
+      expect(bundleRes.status).toBe(200);
+      expect(js).toContain("clawdisA2UI");
+    } finally {
+      await server.close();
+      await fs.rm(dir, { recursive: true, force: true });
+    }
+  });
 });

src/gateway/protocol/schema.ts

@@ -108,6 +108,7 @@ export const HelloOkSchema = Type.Object(
       { additionalProperties: false },
     ),
     snapshot: SnapshotSchema,
+    canvasHostUrl: Type.Optional(NonEmptyString),
     policy: Type.Object(
       {
         maxPayload: Type.Integer({ minimum: 1 }),

src/infra/bridge/server.ts

@@ -79,7 +79,11 @@ type BridgeInvokeResponseFrame = {
   error?: { code: string; message: string } | null;
 };
 
-type BridgeHelloOkFrame = { type: "hello-ok"; serverName: string };
+type BridgeHelloOkFrame = {
+  type: "hello-ok";
+  serverName: string;
+  canvasHostUrl?: string;
+};
 type BridgePairOkFrame = { type: "pair-ok"; token: string };
 type BridgeErrorFrame = { type: "error"; code: string; message: string };
 
@@ -132,6 +136,7 @@ export type NodeBridgeServerOpts = {
   host: string;
   port: number; // 0 = ephemeral
   pairingBaseDir?: string;
+  canvasHostPort?: number;
   onEvent?: (nodeId: string, evt: BridgeEventFrame) => Promise<void> | void;
   onRequest?: (
     nodeId: string,
@@ -180,6 +185,15 @@ export async function startNodeBridgeServer(
       ? opts.serverName.trim()
       : os.hostname();
 
+  const buildCanvasHostUrl = (socket: net.Socket) => {
+    const port = opts.canvasHostPort;
+    if (!port) return undefined;
+    const host = socket.localAddress?.trim();
+    if (!host) return undefined;
+    const formatted = host.includes(":") ? `[${host}]` : host;
+    return `http://${formatted}:${port}`;
+  };
+
   type ConnectionState = {
     socket: net.Socket;
     nodeInfo: NodeBridgeClientInfo;
@@ -356,7 +370,11 @@ export async function startNodeBridgeServer(
         opts.pairingBaseDir,
       );
       connections.set(nodeId, { socket, nodeInfo, invokeWaiters });
-      send({ type: "hello-ok", serverName } satisfies BridgeHelloOkFrame);
+      send({
+        type: "hello-ok",
+        serverName,
+        canvasHostUrl: buildCanvasHostUrl(socket),
+      } satisfies BridgeHelloOkFrame);
       await opts.onAuthenticated?.(nodeInfo);
     };
 
@@ -466,7 +484,11 @@ export async function startNodeBridgeServer(
       };
       connections.set(nodeId, { socket, nodeInfo, invokeWaiters });
       send({ type: "pair-ok", token: wait.token } satisfies BridgePairOkFrame);
-      send({ type: "hello-ok", serverName } satisfies BridgeHelloOkFrame);
+      send({
+        type: "hello-ok",
+        serverName,
+        canvasHostUrl: buildCanvasHostUrl(socket),
+      } satisfies BridgeHelloOkFrame);
       await opts.onAuthenticated?.(nodeInfo);
     };