Iroh: full-stack coverage, a client that builds without Zig, and an iOS app

cmux-tui/Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "crates/cmux-pty",
     "crates/cmux-remote-protocol",
     "crates/cmux-remote",
+    "crates/cmux-remote-mobile",
     "crates/cmux-terminal-client",
     "crates/cmux-relay",
     "crates/cmux-tui-machine-agent-protocol",

cmux-tui/apps/ios/.gitignore

@@ -0,0 +1,2 @@
+# Generated by `xcodegen generate` from project.yml.
+CmuxRemote.xcodeproj/

cmux-tui/apps/ios/Info.plist

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleDisplayName</key>
+	<string>cmux remote</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>NSBonjourServices</key>
+	<array>
+		<string>_cmux._udp</string>
+	</array>
+	<key>NSLocalNetworkUsageDescription</key>
+	<string>cmux connects directly to your computer on this network instead of relaying through the internet.</string>
+	<key>UILaunchScreen</key>
+	<dict/>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>

cmux-tui/apps/ios/README.md

@@ -0,0 +1,64 @@
+# cmux remote for iOS
+
+A phone client for the cmux remote daemon, over Iroh.
+
+It exists to exercise the transport on the network a phone actually has: NAT'd,
+changing between cellular and Wi-Fi, and often unable to reach the daemon
+directly at all. Those are the conditions the relay path and session resume are
+for, and they do not occur on a loopback test.
+
+## What it does
+
+Paste a `cmux://enroll/...` invitation, connect, and get a shell on the machine
+that issued it. The status bar shows whether Iroh settled on a direct or relayed
+path, and counts session resumes, so a walk out of Wi-Fi range is visible rather
+than inferred.
+
+The path picker forces direct-only or relay-only. Automatic is what a user would
+run; the constrained modes are there so a failure can be attributed to one path
+instead of "the network".
+
+## Architecture
+
+The app implements none of the daemon protocol. Enrollment is a
+PSK-authenticated Noise handshake, sessions are mutually authenticated and
+resumable, frames carry per-lane sequence numbers with bounded replay, and Iroh
+adds path selection and relay fallback underneath. A Swift reimplementation
+would be a second set of bugs in exactly the parts that are hardest to test, so
+the app links `cmux-remote-mobile`, a C ABI over the same Rust client the TUI
+uses.
+
+It also carries no VT parser. The daemon keeps the terminal model and answers
+`SnapshotProcessTerminal` with styled runs, so `TerminalScreen` only lays out a
+monospaced grid. Wrapping, scroll regions, and character sets stay on the side
+that already got them right.
+
+## Build
+
+```bash
+brew install xcodegen
+cd cmux-tui/apps/ios
+xcodegen generate
+open CmuxRemote.xcodeproj
+```
+
+The Rust archive builds from a pre-build script, so a plain Xcode build is
+enough. No Zig toolchain is involved: `cmux-remote-mobile` depends on
+`cmux-remote` with `default-features = false`, which leaves out the daemon's
+workspace service and with it libghostty-vt.
+
+`CmuxRemote.xcodeproj` is generated and not committed.
+
+## Getting an invitation
+
+On the machine you want to reach:
+
+```bash
+cmux-tui daemon invite
+```
+
+It prints a `cmux://enroll/...` URI that expires in five minutes and carries the
+daemon's public key plus route hints. The key is what the phone pins during the
+handshake; the hints only say where to try, so a wrong or stale hint cannot
+redirect the session to another host. The daemon asks the machine's owner to
+approve the device before the first session completes.

cmux-tui/apps/ios/Sources/Bridging.h

@@ -0,0 +1 @@
+#import "cmux_remote_mobile.h"

cmux-tui/apps/ios/Sources/CmuxRemoteApp.swift

@@ -0,0 +1,98 @@
+import SwiftUI
+
+@main
+struct CmuxRemoteApp: App {
+    var body: some Scene {
+        WindowGroup {
+            SessionView()
+        }
+    }
+}
+
+@MainActor
+@Observable
+final class SessionModel {
+    enum Phase: Equatable {
+        case disconnected
+        case connecting
+        case connected
+        case failed(String)
+    }
+
+    var invitation = ""
+    var pathMode = RemoteClient.PathMode.auto
+    var root = "~"
+    var phase = Phase.disconnected
+    var terminal: TerminalSnapshot?
+    var connection: ConnectionSnapshot?
+
+    private let client = RemoteClient()
+    private var pump: Task<Void, Never>?
+    private var grid: (cols: UInt16, rows: UInt16) = (80, 24)
+
+    func connect() {
+        guard phase != .connecting else { return }
+        phase = .connecting
+        let invitation = invitation.trimmingCharacters(in: .whitespacesAndNewlines)
+        let pathMode = pathMode
+        let root = root
+        let grid = grid
+        let device = UIDevice.current.name
+
+        Task {
+            do {
+                try await client.connect(
+                    invitation: invitation, deviceName: device, pathMode: pathMode)
+                try await client.openTerminal(root: root, cols: grid.cols, rows: grid.rows)
+                phase = .connected
+                startPump()
+            } catch {
+                phase = .failed(error.localizedDescription)
+            }
+        }
+    }
+
+    func disconnect() {
+        pump?.cancel()
+        pump = nil
+        terminal = nil
+        connection = nil
+        phase = .disconnected
+        Task { await client.disconnect() }
+    }
+
+    func send(_ text: String) {
+        Task { try? await client.write(text) }
+    }
+
+    /// Match the remote PTY to what the phone can actually show. Called on
+    /// rotation and whenever the keyboard changes the visible area.
+    func resize(to grid: (cols: UInt16, rows: UInt16)) {
+        guard grid != self.grid else { return }
+        self.grid = grid
+        guard phase == .connected else { return }
+        Task {
+            try? await client.resize(cols: grid.cols, rows: grid.rows)
+            terminal = await client.terminal()
+        }
+    }
+
+    /// Wait on output, then re-read the model. Blocking on the read rather than
+    /// polling on a timer means an idle shell costs nothing and a busy one
+    /// refreshes as fast as bytes arrive.
+    private func startPump() {
+        pump?.cancel()
+        pump = Task { [client] in
+            var lastSequence: UInt64 = .max
+            while !Task.isCancelled {
+                let produced = await client.readOutput() != nil
+                if let snapshot = await client.terminal(),
+                   produced || snapshot.throughSequence != lastSequence {
+                    lastSequence = snapshot.throughSequence
+                    terminal = snapshot
+                }
+                connection = await client.connection()
+            }
+        }
+    }
+}