Nucleic: Build A Claude “ultracode”-like System

Sources/NucleicApp/AppTheme.swift

@@ -43,6 +43,14 @@ enum AppTheme {
     static let primaryText = dynamic(
         light: NSColor(srgbRed: 0.24, green: 0.24, blue: 0.27, alpha: 1),
         dark: NSColor(srgbRed: 0.80, green: 0.81, blue: 0.83, alpha: 1))
+    /// The signature ultracode purple — the orchestration mode's accent for the effort
+    /// pill, the composer's animated glow, and the multi-agent transcript cards. A vivid
+    /// violet in light mode; a softer, brighter lavender in dark so it glows without
+    /// burning. Mode-independent (a brand color, not a categorical status), so it lives
+    /// here next to the other app surfaces rather than in the color-vision palette.
+    static let ultracode = dynamic(
+        light: NSColor(srgbRed: 0.55, green: 0.28, blue: 0.95, alpha: 1),
+        dark: NSColor(srgbRed: 0.72, green: 0.55, blue: 1.0, alpha: 1))
 
     /// A `Color` that resolves to `light`/`dark` against the view's effective
     /// appearance (driven by `.preferredColorScheme`).

Sources/NucleicApp/HomeView.swift

@@ -210,6 +210,7 @@ struct HomeView: View {
                     .frame(height: composerHeight)
                     .padding(8)
                     .background(.quaternary.opacity(0.5), in: .rect(cornerRadius: 8))
+                    .ultracodeGlow(active: isUltracode)
                 Button(action: start) {
                     SubmitKeyIcon(mode: submitMode)
                 }
@@ -278,6 +279,9 @@ struct HomeView: View {
         .help("Model for the new chat")
     }
 
+    /// Whether the chat about to start runs in ultracode (orchestration) mode.
+    private var isUltracode: Bool { ModelCatalog.isUltracode(effectiveEffort) }
+
     private var effortMenu: some View {
         Menu {
             ForEach(ModelCatalog.efforts, id: \.self) { level in
@@ -285,12 +289,35 @@ struct HomeView: View {
                     choiceLabel(level, isSelected: level == effectiveEffort, isDefault: level == defaultEffort)
                 }
             }
+            // Ultracode sits below the API levels, set apart: it isn't an effort level but an
+            // orchestration mode (xhigh + standing consent to fan out to subagents).
+            Divider()
+            Button { effortOverride = ModelCatalog.ultracodeEffort } label: {
+                ultracodeMenuItem
+            }
         } label: {
-            Text("Effort: \(effectiveEffort)")
+            if isUltracode {
+                UltracodeEffortLabel()
+            } else {
+                Text("Effort: \(effectiveEffort)")
+            }
         }
         .menuStyle(.button)
         .fixedSize()
-        .help("Reasoning effort for the new chat")
+        .help(isUltracode ? ModelCatalog.ultracodeBlurb : "Reasoning effort for the new chat")
+    }
+
+    /// The Ultracode row in an effort menu: a sparkles glyph (a checkmark when it's the
+    /// selected mode), "Ultracode", and the "(default)" suffix when it's the app default.
+    @ViewBuilder
+    private var ultracodeMenuItem: some View {
+        let selected = isUltracode
+        let isDefault = ModelCatalog.isUltracode(defaultEffort)
+        Label {
+            Text("Ultracode") + (isDefault ? Text("  (default)") : Text(""))
+        } icon: {
+            Image(systemName: selected ? "checkmark" : UltracodeStyle.symbol)
+        }
     }
 
     /// Auto-approve mode for the chat about to be started; defaults to the app-wide

Sources/NucleicApp/ModelCatalog.swift

@@ -1,4 +1,5 @@
 import Foundation
+import NucleicCore
 
 /// Selectable Claude model SKUs and effort levels, plus the persistence keys for
 /// the per-app defaults applied to new chats.
@@ -17,6 +18,26 @@ enum ModelCatalog {
     ]
     static let efforts: [String] = ["low", "medium", "high", "xhigh", "max"]
 
+    /// The "ultracode" orchestration mode (`OrchestrationMode`). It rides in the effort menu
+    /// like a level, but it isn't an API effort — it pairs `xhigh` with standing consent to
+    /// fan work out to parallel subagents. Kept out of `efforts` (the canonical API levels) so
+    /// it can be presented separately, below a divider, with its own purple treatment.
+    static let ultracodeEffort = OrchestrationMode.effortSentinel
+
+    /// Whether `effort` selects ultracode.
+    static func isUltracode(_ effort: String?) -> Bool { OrchestrationMode.isUltracode(effort) }
+
+    /// A pretty, human label for an effort level — ultracode reads "Ultracode"; the plain API
+    /// levels keep their lowercase word (matching how they're shown in the menu today).
+    static func effortDisplayName(_ effort: String) -> String {
+        isUltracode(effort) ? "Ultracode" : effort
+    }
+
+    /// One-line description of what ultracode does, for the menu item's help tooltip.
+    static let ultracodeBlurb =
+        "Ultracode: maximum-effort orchestration. Runs at xhigh and lets the agent fan work "
+        + "out to parallel subagents on its own for thorough, verified results (uses more tokens)."
+
     /// A pretty, human label for a model SKU (e.g. "claude-sonnet-4-6" → "Sonnet
     /// 4.6"). The two Opus 4.8 SKUs share the name "Opus 4.8"; their context window
     /// is conveyed by the picker badge (see `contextBadge`). Falls back to a

Sources/NucleicApp/SessionDetailView.swift

@@ -259,6 +259,9 @@ struct SessionDetailView: View {
         .help("Model for the next turn")
     }
 
+    /// Whether the next turn runs in ultracode (orchestration) mode.
+    private var isUltracode: Bool { ModelCatalog.isUltracode(effectiveEffort) }
+
     private var effortMenu: some View {
         Menu {
             ForEach(ModelCatalog.efforts, id: \.self) { level in
@@ -266,18 +269,44 @@ struct SessionDetailView: View {
                     choiceLabel(level, isSelected: level == effectiveEffort, isDefault: level == defaultEffort)
                 }
             }
+            // Ultracode is an orchestration mode, not an API level — set it apart below the
+            // canonical efforts (xhigh + standing consent to fan out to parallel subagents).
+            Divider()
+            Button { Task { await store.setOpenSessionEffort(ModelCatalog.ultracodeEffort) } } label: {
+                ultracodeMenuItem
+            }
         } label: {
-            Text("Effort: \(effectiveEffort)")
-                .padding(.horizontal, 8)
-                .padding(.vertical, 4)
-                .contentShape(Rectangle())
+            Group {
+                if isUltracode {
+                    UltracodeEffortLabel()
+                } else {
+                    Text("Effort: \(effectiveEffort)")
+                }
+            }
+            .padding(.horizontal, 8)
+            .padding(.vertical, 4)
+            .contentShape(Rectangle())
         }
         .menuStyle(.button)
         .buttonStyle(.plain)
         .background(.quaternary.opacity(0.5), in: .rect(cornerRadius: 6))
-        .overlay(RoundedRectangle(cornerRadius: 6).strokeBorder(.quaternary, lineWidth: 1))
+        .overlay(RoundedRectangle(cornerRadius: 6).strokeBorder(
+            isUltracode ? AnyShapeStyle(AppTheme.ultracode.opacity(0.6)) : AnyShapeStyle(.quaternary),
+            lineWidth: 1))
         .fixedSize()
-        .help("Reasoning effort for the next turn")
+        .help(isUltracode ? ModelCatalog.ultracodeBlurb : "Reasoning effort for the next turn")
+    }
+
+    /// The Ultracode row in the effort menu: a sparkles glyph (checkmark when selected),
+    /// "Ultracode", and "(default)" when it's the app default.
+    @ViewBuilder
+    private var ultracodeMenuItem: some View {
+        let isDefault = ModelCatalog.isUltracode(defaultEffort)
+        Label {
+            Text("Ultracode") + (isDefault ? Text("  (default)") : Text(""))
+        } icon: {
+            Image(systemName: isUltracode ? "checkmark" : UltracodeStyle.symbol)
+        }
     }
 
     private var autoToggle: some View {
@@ -891,6 +920,8 @@ struct SessionDetailView: View {
                     .frame(height: composerHeight)
                     .padding(8)
                     .background(.quaternary.opacity(0.5), in: .rect(cornerRadius: 8))
+                    // An archived chat is inert, so don't glow even if its effort was ultracode.
+                    .ultracodeGlow(active: isUltracode && !isArchived)
                 if isArchived {
                     // Read-only chat: the send/cmd-return control is replaced by Unarchive,
                     // the only way to make the composer and messages interactive again.

Sources/NucleicApp/TranscriptRow.swift

@@ -55,9 +55,16 @@ struct TranscriptRow: View {
         case .tool(_, let call, let result, let finished):
             toolRow(call: call, result: result, finished: finished).modifier(NonResponsePadding())
         case .toolGroup(_, let signature, let calls):
-            // The block supplies the single rounded container + padding; its inner
-            // rows render chrome-less so they read as one contiguous card.
-            ToolGroupRow(signature: signature, calls: calls).modifier(NonResponsePadding())
+            // A run made entirely of subagent spawns is a multi-agent fan-out — render it
+            // as the purple orchestration card (parallel subagents with live status) rather
+            // than the generic tool block.
+            if calls.allSatisfy({ Self.isSubagentCall($0.call) }) {
+                OrchestrationCard(calls: calls).modifier(NonResponsePadding())
+            } else {
+                // The block supplies the single rounded container + padding; its inner
+                // rows render chrome-less so they read as one contiguous card.
+                ToolGroupRow(signature: signature, calls: calls).modifier(NonResponsePadding())
+            }
         case .event(let event):
             rawEventBody(event).modifier(NonResponsePadding())
         }
@@ -75,12 +82,23 @@ struct TranscriptRow: View {
             card
         } else if let card = gitCommitCard(call: call, result: result) {
             card
+        } else if Self.isSubagentCall(call) {
+            // A lone subagent spawn renders as its own purple subagent card (type, task, and
+            // running/done/failed status), making delegated work read distinctly from the
+            // agent's own tool calls.
+            SubagentCard(call: call, result: result, finished: finished)
         } else {
             ToolCallRow(call: call, result: result, finished: finished,
                         worktreeRoot: store.openSession?.worktreePath)
         }
     }
 
+    /// Whether `call` spawns a subagent — Claude Code's `Task` tool (and the `Agent` alias).
+    /// These get the dedicated subagent / orchestration cards instead of a generic tool row.
+    static func isSubagentCall(_ call: ToolCall) -> Bool {
+        call.name == "Task" || call.name == "Agent"
+    }
+
     /// A git commit pipeline renders as the same structured card the approval shows — subject,
     /// body, and steps — rather than the raw "Bash <command>" row. The literal command stays
     /// reachable under the card's "Show command", and a trailing `git log` result (the new
@@ -988,3 +1006,277 @@ private struct NonResponsePadding: ViewModifier {
         content.padding(.vertical, 8)
     }
 }
+
+// MARK: - Subagent & multi-agent cards
+//
+// Claude Code spawns subagents through the `Task` tool. Nucleic surfaces that delegated
+// work in the ultracode purple so it reads distinctly from the agent's own tool calls: a
+// lone `Task` becomes a `SubagentCard`, and a parallel wave of them becomes an
+// `OrchestrationCard`. Both build entirely from the existing tool-call/result events
+// (`ToolCall.parentToolCallID` already links a subagent's inner calls to its parent), so
+// no protocol or projection changes are needed.
+
+/// The lifecycle state of a spawned subagent, read from its `Task` tool result: no result
+/// yet → still working; an error result → failed; otherwise → done.
+private enum SubagentRunState {
+    case running, done, failed
+
+    init(result: ToolResult?) {
+        guard let result else { self = .running; return }
+        self = result.isError ? .failed : .done
+    }
+
+    var label: String {
+        switch self {
+        case .running: "Working"
+        case .done: "Done"
+        case .failed: "Failed"
+        }
+    }
+
+    /// Status tint: done/failed reuse the shared palette so they match the rest of the app;
+    /// a still-running subagent glows in the ultracode purple.
+    func color(_ palette: AppPalette) -> Color {
+        switch self {
+        case .running: AppTheme.ultracode
+        case .done: palette.success
+        case .failed: palette.danger
+        }
+    }
+}
+
+/// Pulls the human-facing bits out of a `Task` tool call so the subagent cards agree on what
+/// to show.
+private enum Subagent {
+    /// The subagent flavor (`subagent_type`: "Explore", "general-purpose", …), or nil.
+    static func type(_ call: ToolCall) -> String? {
+        let raw = call.input["subagent_type"]?.stringValue?
+            .trimmingCharacters(in: .whitespacesAndNewlines)
+        return (raw?.isEmpty == false) ? raw : nil
+    }
+
+    /// The one-line task the parent handed the subagent (`description`), falling back to the
+    /// full `prompt`, then a generic label.
+    static func taskLabel(_ call: ToolCall) -> String {
+        if let description = call.input["description"]?.stringValue?
+            .trimmingCharacters(in: .whitespacesAndNewlines), !description.isEmpty {
+            return description
+        }
+        if let prompt = call.input["prompt"]?.stringValue?
+            .trimmingCharacters(in: .whitespacesAndNewlines), !prompt.isEmpty {
+            return prompt
+        }
+        return "Subagent task"
+    }
+
+    /// "Explore — find the composer", joining the flavor and task for a compact one-liner.
+    static func headline(_ call: ToolCall) -> String {
+        let label = taskLabel(call)
+        if let type = type(call) { return "\(type) — \(label)" }
+        return label
+    }
+
+    /// The subagent's returned report, or nil while it's still working / reported nothing.
+    static func report(_ result: ToolResult?) -> String? {
+        guard let result else { return nil }
+        let text = TranscriptRow.resultText(result.content)
+        return text.isEmpty ? nil : text
+    }
+}
+
+/// A small leading status glyph for a subagent — a purple spinner while it works, a green
+/// check or red cross once it settles.
+private struct SubagentStatusGlyph: View {
+    @Environment(\.appPalette) private var palette
+    let state: SubagentRunState
+
+    var body: some View {
+        Group {
+            switch state {
+            case .running: ProgressView().controlSize(.mini).tint(AppTheme.ultracode)
+            case .done: Image(systemName: "checkmark.circle.fill").foregroundStyle(palette.success)
+            case .failed: Image(systemName: "xmark.octagon.fill").foregroundStyle(palette.danger)
+            }
+        }
+        .font(.caption)
+        .frame(width: 16)
+    }
+}
+
+/// A status pill (spinner / check / cross + word) for the header of a subagent card.
+private struct SubagentStatusChip: View {
+    @Environment(\.appPalette) private var palette
+    let state: SubagentRunState
+
+    var body: some View {
+        HStack(spacing: 4) {
+            SubagentStatusGlyph(state: state).frame(width: 14)
+            Text(state.label)
+        }
+        .font(.caption2.weight(.medium))
+        .foregroundStyle(state.color(palette))
+        .padding(.horizontal, 7).padding(.vertical, 3)
+        .background(state.color(palette).opacity(0.14), in: Capsule())
+    }
+}
+
+/// One delegated subagent (`Task`), as a purple card: its type and the task it was given, a
+/// live Working / Done / Failed status, and — once it reports back — its findings, collapsed
+/// by default. Mirrors the other transcript cards (GitBlockCard et al.) in the ultracode hue.
+private struct SubagentCard: View {
+    @Environment(\.appPalette) private var palette
+    let call: ToolCall
+    let result: ToolResult?
+    let finished: Bool
+    @State private var expanded = false
+
+    private let accent = AppTheme.ultracode
+    private var state: SubagentRunState { SubagentRunState(result: result) }
+    private var report: String? { Subagent.report(result) }
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 0) {
+            header
+                .contentShape(Rectangle())
+                .onTapGesture {
+                    guard report != nil else { return }
+                    withAnimation(.easeInOut(duration: 0.15)) { expanded.toggle() }
+                }
+            if expanded, let report {
+                Divider().overlay(accent.opacity(0.2))
+                Text(report)
+                    .font(.callout)
+                    .foregroundStyle(AppTheme.primaryText)
+                    .textSelection(.enabled)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .padding(.horizontal, 12).padding(.vertical, 10)
+            }
+        }
+        .background(accent.opacity(0.08))
+        .overlay(RoundedRectangle(cornerRadius: 8).strokeBorder(accent.opacity(0.22), lineWidth: 1))
+        .clipShape(RoundedRectangle(cornerRadius: 8))
+    }
+
+    private var header: some View {
+        VStack(alignment: .leading, spacing: 6) {
+            HStack(alignment: .firstTextBaseline, spacing: 10) {
+                Image(systemName: "person.2.fill")
+                    .font(.body)
+                    .foregroundStyle(accent)
+                    .frame(width: 18)
+                (Text("Subagent")
+                    + (Subagent.type(call).map { Text(" · \($0)").foregroundColor(.secondary) } ?? Text("")))
+                    .font(.body.weight(.semibold))
+                    .foregroundStyle(AppTheme.primaryText)
+                Spacer(minLength: 6)
+                SubagentStatusChip(state: state)
+                if report != nil {
+                    Image(systemName: expanded ? "chevron.up" : "chevron.down")
+                        .font(.caption2).foregroundStyle(.secondary)
+                }
+            }
+            Text(Subagent.taskLabel(call))
+                .font(.callout)
+                .foregroundStyle(AppTheme.primaryText)
+                .lineLimit(expanded ? nil : 2)
+                .truncationMode(.tail)
+                .fixedSize(horizontal: false, vertical: true)
+        }
+        .padding(.horizontal, 12).padding(.vertical, 10)
+    }
+}
+
+/// A multi-agent fan-out: a wave of two or more subagents (`Task` calls) spawned together,
+/// the visual centerpiece of ultracode's orchestration. The header sums up the wave (count +
+/// overall status); collapsed, each subagent is a one-line status row; expanded, each shows
+/// its task and returned report. Purple throughout to mark it as orchestration work.
+private struct OrchestrationCard: View {
+    @Environment(\.appPalette) private var palette
+    let calls: [(call: ToolCall, result: ToolResult?, finished: Bool)]
+    @State private var expanded = false
+
+    private let accent = AppTheme.ultracode
+
+    /// Overall wave status: failed if any subagent failed, else running if any is still
+    /// working, else done.
+    private var overall: SubagentRunState {
+        let states = calls.map { SubagentRunState(result: $0.result) }
+        if states.contains(where: { if case .failed = $0 { true } else { false } }) { return .failed }
+        if states.contains(where: { if case .running = $0 { true } else { false } }) { return .running }
+        return .done
+    }
+
+    private var doneCount: Int { calls.filter { $0.result != nil }.count }
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 0) {
+            header
+                .contentShape(Rectangle())
+                .onTapGesture {
+                    withAnimation(.easeInOut(duration: 0.15)) { expanded.toggle() }
+                }
+            ForEach(Array(calls.enumerated()), id: \.element.call.toolCallID) { _, entry in
+                Divider().overlay(accent.opacity(0.18))
+                if expanded {
+                    expandedRow(entry)
+                } else {
+                    collapsedRow(entry)
+                }
+            }
+        }
+        .background(accent.opacity(0.08))
+        .overlay(RoundedRectangle(cornerRadius: 8).strokeBorder(accent.opacity(0.22), lineWidth: 1))
+        .clipShape(RoundedRectangle(cornerRadius: 8))
+    }
+
+    private var header: some View {
+        HStack(alignment: .firstTextBaseline, spacing: 10) {
+            Image(systemName: "rectangle.3.group.fill")
+                .font(.body)
+                .foregroundStyle(accent)
+                .frame(width: 18)
+            VStack(alignment: .leading, spacing: 1) {
+                Text("Multi-agent fan-out")
+                    .font(.body.weight(.semibold))
+                    .foregroundStyle(AppTheme.primaryText)
+                Text("\(calls.count) subagents · \(doneCount) done")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
+            Spacer(minLength: 6)
+            SubagentStatusChip(state: overall)
+            Image(systemName: expanded ? "chevron.up" : "chevron.down")
+                .font(.caption2).foregroundStyle(.secondary)
+        }
+        .padding(.horizontal, 12).padding(.vertical, 10)
+    }
+
+    /// Collapsed: one line per subagent — status glyph + "Type — task", truncated.
+    private func collapsedRow(_ entry: (call: ToolCall, result: ToolResult?, finished: Bool)) -> some View {
+        HStack(alignment: .firstTextBaseline, spacing: 9) {
+            SubagentStatusGlyph(state: SubagentRunState(result: entry.result))
+            Text(Subagent.headline(entry.call))
+                .font(.callout)
+                .foregroundStyle(AppTheme.primaryText)
+                .lineLimit(1)
+                .truncationMode(.tail)
+            Spacer(minLength: 6)
+        }
+        .padding(.horizontal, 12).padding(.vertical, 8)
+    }
+
+    /// Expanded: the same status line plus the subagent's returned report beneath it.
+    private func expandedRow(_ entry: (call: ToolCall, result: ToolResult?, finished: Bool)) -> some View {
+        VStack(alignment: .leading, spacing: 5) {
+            collapsedRow(entry)
+            if let report = Subagent.report(entry.result) {
+                Text(report)
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+                    .textSelection(.enabled)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .padding(.horizontal, 12).padding(.bottom, 8)
+            }
+        }
+    }
+}

Sources/NucleicApp/UltracodeStyle.swift

@@ -0,0 +1,101 @@
+import SwiftUI
+
+/// Shared visual language for ultracode (orchestration) mode: the signature purple, a
+/// gently-pulsing composer glow, and the small effort-pill label. Kept together so the
+/// home chat bar, the session composer, and the effort menus all read identically.
+enum UltracodeStyle {
+    /// SF Symbol that marks ultracode throughout the UI — the same sparkles used for the
+    /// agent's thinking, so "extra intelligence" reads consistently.
+    static let symbol = "sparkles"
+
+    /// A soft violet gradient used for the glow stroke, hot corner to cool corner.
+    static func strokeGradient(intensity: Double) -> LinearGradient {
+        LinearGradient(
+            colors: [
+                AppTheme.ultracode.opacity(0.55 + 0.40 * intensity),
+                AppTheme.ultracode.opacity(0.28 + 0.30 * intensity),
+            ],
+            startPoint: .topLeading, endPoint: .bottomTrailing)
+    }
+}
+
+/// A cute, restrained purple halo that breathes around a view while ultracode is the active
+/// effort. Mirrors `StreakBadge`'s idiom — a single `@State` flag toggled to kick off an
+/// `easeInOut(...).repeatForever(autoreverses:)` pulse — so the animation feels native to the
+/// app. The halo crests brighter and never collapses to nothing, so even at the trough it
+/// reads as "ultracode is on", not a flicker. Honors Reduce Motion: the glow still shows, it
+/// just holds steady instead of pulsing.
+struct UltracodeGlow: ViewModifier {
+    /// Whether ultracode is the selected effort. When false the modifier is inert (no glow,
+    /// no animation), so a plain chat composer is untouched.
+    var active: Bool
+    var cornerRadius: CGFloat = 8
+
+    @Environment(\.accessibilityReduceMotion) private var reduceMotion
+    /// Toggled once the view is on screen (and whenever `active` flips), which starts —
+    /// or, under Reduce Motion, simply settles — the repeating pulse.
+    @State private var pulsing = false
+
+    func body(content: Content) -> some View {
+        // Animate only while ultracode is on, the pulse has been kicked off, and the user
+        // hasn't asked to reduce motion; otherwise the halo holds at a calm mid intensity.
+        let animating = active && pulsing && !reduceMotion
+        let intensity = animating ? 1.0 : 0.45
+        return content
+            .overlay {
+                if active {
+                    RoundedRectangle(cornerRadius: cornerRadius, style: .continuous)
+                        .strokeBorder(UltracodeStyle.strokeGradient(intensity: intensity),
+                                      lineWidth: animating ? 1.6 : 1.2)
+                        .shadow(color: AppTheme.ultracode.opacity(animating ? 0.55 : 0.22),
+                                radius: animating ? 9 : 4)
+                        // A wider, fainter outer bloom so the glow feels soft rather than a
+                        // hard ring — the second shadow reads as ambient light around the box.
+                        .shadow(color: AppTheme.ultracode.opacity(animating ? 0.30 : 0),
+                                radius: animating ? 16 : 0)
+                        .animation(
+                            reduceMotion
+                                ? .default
+                                : .easeInOut(duration: 1.8).repeatForever(autoreverses: true),
+                            value: pulsing)
+                        .allowsHitTesting(false)  // purely decorative — never eats composer taps
+                        .transition(.opacity)
+                }
+            }
+            .animation(.easeInOut(duration: 0.3), value: active)
+            .onAppear { pulsing = active }
+            .onChange(of: active) { _, now in pulsing = now }
+    }
+}
+
+extension View {
+    /// Wrap a composer (or any rounded box) in the ultracode purple glow while `active`.
+    /// Place it *after* the view's own background so the halo sits around the box.
+    func ultracodeGlow(active: Bool, cornerRadius: CGFloat = 8) -> some View {
+        modifier(UltracodeGlow(active: active, cornerRadius: cornerRadius))
+    }
+}
+
+/// The effort-menu trigger label when ultracode is selected: a sparkles glyph + "Ultracode"
+/// in the signature purple, replacing the plain "Effort: xhigh" text so the mode is obvious
+/// at a glance. The sparkle does a slow twinkle to echo the composer glow (steady under
+/// Reduce Motion).
+struct UltracodeEffortLabel: View {
+    @Environment(\.accessibilityReduceMotion) private var reduceMotion
+    @State private var twinkle = false
+
+    var body: some View {
+        let on = twinkle && !reduceMotion
+        return HStack(spacing: 4) {
+            Image(systemName: UltracodeStyle.symbol)
+                .opacity(on ? 1.0 : 0.7)
+                .scaleEffect(on ? 1.0 : 0.9)
+                .animation(
+                    reduceMotion ? .default : .easeInOut(duration: 1.2).repeatForever(autoreverses: true),
+                    value: twinkle)
+            Text("Ultracode")
+        }
+        .foregroundStyle(AppTheme.ultracode)
+        .onAppear { twinkle = true }
+    }
+}

Sources/NucleicCore/OrchestrationMode.swift

@@ -0,0 +1,70 @@
+import Foundation
+
+/// "Ultracode" — Nucleic's orchestration mode, modeled on Claude Code's ultracode.
+///
+/// Ultracode is *not* an API effort level. It pairs the documented `xhigh` effort with
+/// standing consent for the agent to fan work out to parallel subagents (the `Task` /
+/// `Workflow` tools) by default. The user selects it in the effort menu like any other
+/// level, but it never reaches a backend verbatim:
+///
+/// - `resolvedEffort` maps the `ultracode` sentinel to its real effort, `xhigh`, so the
+///   `claude --effort` (and Codex) flag only ever sees a level the API accepts.
+/// - `combinedSystemPrompt` rides the standing-consent text in on `--append-system-prompt`.
+///   The CLI doesn't persist that flag, so `SessionController` re-applies it every turn —
+///   which is exactly the per-turn "mode reminder" the orchestration design calls for, so
+///   no separate refresher counter is needed here.
+///
+/// Keeping the sentinel, the effort mapping, and the consent text in one place lets the UI,
+/// the core, and the tests agree on what "ultracode" means.
+public enum OrchestrationMode {
+    /// The sentinel stored in `Session.effort` when the user picks Ultracode. Chosen so it
+    /// never collides with a real API effort level and is obvious in the persisted store.
+    public static let effortSentinel = "ultracode"
+
+    /// The real effort level ultracode runs at. The xhigh ceiling is the most thorough the
+    /// API documents; ultracode adds the fan-out consent on top, not a hidden higher level.
+    public static let resolvedUltracodeEffort = "xhigh"
+
+    /// Whether `effort` selects ultracode (case-insensitive, whitespace-tolerant).
+    public static func isUltracode(_ effort: String?) -> Bool {
+        effort?.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() == effortSentinel
+    }
+
+    /// The effort actually handed to a backend: `ultracode` resolves to `xhigh`; everything
+    /// else passes through untouched. One-way — the resolved value never flows back into
+    /// `Session.effort`, so the UI keeps showing "Ultracode".
+    public static func resolvedEffort(_ effort: String?) -> String? {
+        isUltracode(effort) ? resolvedUltracodeEffort : effort
+    }
+
+    /// The standing-consent instruction appended to the system prompt while ultracode is on.
+    /// It grants the agent blanket permission to orchestrate multi-agent workflows for the
+    /// session and points at the fan-out / verification patterns to reach for. Re-sent every
+    /// turn by the caller, so it doubles as the mode's recurring reminder.
+    public static let consentPrompt = """
+        Ultracode (orchestration mode) is on: optimize for the most exhaustive, correct \
+        answer rather than the fastest one, and put maximum thoroughness behind every \
+        substantive request. Standing consent: you may fan work out to parallel subagents \
+        (the Task tool, or a Workflow/orchestration tool when available) on every substantive \
+        task without asking first — scout the task yourself, then decompose it into \
+        independent subtasks sized to the problem's natural structure and run them \
+        concurrently, reading their results between phases. Lean on the quality patterns that \
+        fit: adversarial verification (a second wave that tries to refute the first wave's \
+        findings against the source), a completeness critic (one agent hunting for what the \
+        others missed), and multi-phase sequencing (understand, design, implement, review as \
+        separate fan-outs). Work solo only on conversational or trivial turns. The fan-out \
+        multiplies token usage, so keep each subtask scoped to a distinct concern rather than \
+        splitting per line or file.
+        """
+
+    /// The system prompt appended for a run: the caller's environment guidance (sandbox build
+    /// instructions, etc.) plus, when `effort` selects ultracode, the orchestration consent.
+    /// Returns `nil` when neither applies so the backend flag is omitted entirely; joins the
+    /// two with a blank line when both are present, so the consent reads as its own paragraph.
+    public static func combinedSystemPrompt(environment: String?, effort: String?) -> String? {
+        let parts = [environment, isUltracode(effort) ? consentPrompt : nil]
+            .compactMap { $0 }
+            .filter { !$0.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty }
+        return parts.isEmpty ? nil : parts.joined(separator: "\n\n")
+    }
+}

Sources/NucleicCore/SessionController.swift

@@ -141,6 +141,20 @@ public actor SessionController {
         return Self.sandboxBuildGuidance(allowHostExec: allowsHostExec)
     }
 
+    /// The effort actually sent to the backend. `ultracode` is a Nucleic-only orchestration
+    /// mode, not an API effort level, so it resolves to its real effort (`xhigh`); every other
+    /// level passes through. The resolved value never flows back into `session.effort`, so the
+    /// UI keeps showing "Ultracode" (`OrchestrationMode`).
+    private var resolvedEffort: String? { OrchestrationMode.resolvedEffort(session.effort) }
+
+    /// The system prompt appended to a run: the sandbox build guidance (when sandboxed) plus,
+    /// in ultracode mode, the orchestration standing-consent text. Re-applied on every start /
+    /// resume because the CLI doesn't persist `--append-system-prompt`, which keeps the consent
+    /// in effect as ultracode's per-turn reminder.
+    private var appendedSystemPrompt: String? {
+        OrchestrationMode.combinedSystemPrompt(environment: environmentSystemPrompt, effort: session.effort)
+    }
+
     /// The build-environment guidance text. Separated from `environmentSystemPrompt` so it can be
     /// unit-tested without standing up a full controller. Describes the container's own toolchain
     /// (Node/npm, Python/pip, make/gcc — see the sandbox image in `ContainerRuntime`) and routes
@@ -422,12 +436,12 @@ public actor SessionController {
             worktree: worktreePath,
             prompt: prompt,
             model: session.model,
-            effort: session.effort,
+            effort: resolvedEffort,
             autoApprove: session.auto,
             approvalPolicy: .interactive,
             container: containerSpec(),
             allowHostExec: allowsHostExec,
-            appendSystemPrompt: environmentSystemPrompt)
+            appendSystemPrompt: appendedSystemPrompt)
         consume(backend.start(run), injectingUserText: prompt.plainText)
     }
 
@@ -443,7 +457,7 @@ public actor SessionController {
             worktree: worktreePath,
             container: containerSpec(),
             allowHostExec: allowsHostExec,
-            appendSystemPrompt: environmentSystemPrompt)
+            appendSystemPrompt: appendedSystemPrompt)
         consume(backend.resume(spec), injectingUserText: nil)
     }
 
@@ -538,18 +552,18 @@ public actor SessionController {
             let spec = ResumeSpec(
                 sessionID: session.id, backendSessionID: backendSessionID,
                 worktree: worktreePath, prompt: input,
-                model: session.model, effort: session.effort, autoApprove: session.auto,
+                model: session.model, effort: resolvedEffort, autoApprove: session.auto,
                 container: container, allowHostExec: allowsHostExec,
-                appendSystemPrompt: environmentSystemPrompt)
+                appendSystemPrompt: appendedSystemPrompt)
             consume(backend.resume(spec), injectingUserText: nil)
         } else {
             // No turn has run yet → this message starts the session.
             let run = RunSpec(
                 sessionID: session.id, worktree: worktreePath, prompt: input,
-                model: session.model, effort: session.effort,
+                model: session.model, effort: resolvedEffort,
                 autoApprove: session.auto, approvalPolicy: .interactive,
                 container: container, allowHostExec: allowsHostExec,
-                appendSystemPrompt: environmentSystemPrompt)
+                appendSystemPrompt: appendedSystemPrompt)
             consume(backend.start(run), injectingUserText: nil)
         }
     }

Tests/NucleicCoreTests/OrchestrationModeTests.swift

@@ -0,0 +1,53 @@
+import Foundation
+import Testing
+
+@testable import NucleicCore
+
+@Suite("Ultracode orchestration mode")
+struct OrchestrationModeTests {
+    @Test func detectsUltracodeSentinel() {
+        #expect(OrchestrationMode.isUltracode("ultracode"))
+        #expect(OrchestrationMode.isUltracode("  Ultracode  "))  // trimmed, case-insensitive
+        #expect(!OrchestrationMode.isUltracode("xhigh"))
+        #expect(!OrchestrationMode.isUltracode("high"))
+        #expect(!OrchestrationMode.isUltracode(nil))
+    }
+
+    @Test func resolvesUltracodeToXhigh() {
+        // The sentinel never reaches a backend verbatim — it maps to its real effort level.
+        #expect(OrchestrationMode.resolvedEffort("ultracode") == "xhigh")
+        #expect(OrchestrationMode.resolvedEffort("Ultracode") == "xhigh")
+    }
+
+    @Test func passesThroughRealEffortLevels() {
+        for level in ["low", "medium", "high", "xhigh", "max"] {
+            #expect(OrchestrationMode.resolvedEffort(level) == level)
+        }
+        #expect(OrchestrationMode.resolvedEffort(nil) == nil)
+    }
+
+    @Test func appendsConsentOnlyInUltracode() {
+        // Off: nothing to append when there's no environment guidance either.
+        #expect(OrchestrationMode.combinedSystemPrompt(environment: nil, effort: "high") == nil)
+        // On: the consent text is appended.
+        let consentOnly = OrchestrationMode.combinedSystemPrompt(environment: nil, effort: "ultracode")
+        #expect(consentOnly == OrchestrationMode.consentPrompt)
+    }
+
+    @Test func mergesEnvironmentGuidanceWithConsent() {
+        let environment = "Build environment: you are running inside a Linux container."
+        // Not ultracode → only the environment guidance survives.
+        #expect(
+            OrchestrationMode.combinedSystemPrompt(environment: environment, effort: "max") == environment)
+        // Ultracode → both, environment first, consent as its own paragraph.
+        let merged = OrchestrationMode.combinedSystemPrompt(environment: environment, effort: "ultracode")
+        #expect(merged == environment + "\n\n" + OrchestrationMode.consentPrompt)
+    }
+
+    @Test func consentMentionsStandingFanOut() {
+        // The contract that makes ultracode work: standing consent to fan out to subagents.
+        let consent = OrchestrationMode.consentPrompt.lowercased()
+        #expect(consent.contains("standing consent"))
+        #expect(consent.contains("subagent"))
+    }
+}

ios/NucleicRemote/NucleicRemote/Views/Composer.swift

@@ -8,6 +8,7 @@ struct StartChatComposer: View {
     @State private var projectID: ProjectID?
     @State private var draft = ""
     @State private var auto = false
+    @State private var effort = MobileEfforts.fallback
 
     private var projects: [WireProject] { store.dashboard.projects }
     private var selected: WireProject? {
@@ -27,6 +28,7 @@ struct StartChatComposer: View {
                         .font(.subheadline)
                 }
                 Spacer()
+                EffortMenu(effort: $effort)
                 Toggle(isOn: $auto) {
                     Label("Auto", systemImage: auto ? "bolt.fill" : "bolt.slash")
                 }
@@ -38,9 +40,10 @@ struct StartChatComposer: View {
                 TextField("Describe a task…", text: $draft, axis: .vertical)
                     .textFieldStyle(.roundedBorder)
                     .lineLimit(1...5)
+                    .ultracodeGlow(active: MobileEfforts.isUltracode(effort))
                 Button {
                     if let project = selected {
-                        store.startChat(in: project.id, message: draft, auto: auto)
+                        store.startChat(in: project.id, message: draft, effort: effort, auto: auto)
                         draft = ""
                     }
                 } label: {

ios/NucleicRemote/NucleicRemote/Views/ProjectsView.swift

@@ -47,6 +47,7 @@ struct ProjectDetailView: View {
     @EnvironmentObject var store: RemoteStore
     let project: WireProject
     @State private var draft = ""
+    @State private var effort = MobileEfforts.fallback
 
     private var sessions: [WireSessionSummary] {
         store.liveSessions
@@ -57,14 +58,21 @@ struct ProjectDetailView: View {
     var body: some View {
         List {
             Section {
-                HStack(alignment: .bottom, spacing: 8) {
-                    TextField("Start a chat in \(project.name)…", text: $draft, axis: .vertical)
-                        .textFieldStyle(.roundedBorder).lineLimit(1...4)
-                    Button {
-                        store.startChat(in: project.id, message: draft)
-                        draft = ""
-                    } label: { Image(systemName: "arrow.up.circle.fill").font(.title2) }
-                        .disabled(draft.trimmingCharacters(in: .whitespaces).isEmpty || !store.canControl)
+                VStack(alignment: .leading, spacing: 8) {
+                    HStack {
+                        EffortMenu(effort: $effort)
+                        Spacer()
+                    }
+                    HStack(alignment: .bottom, spacing: 8) {
+                        TextField("Start a chat in \(project.name)…", text: $draft, axis: .vertical)
+                            .textFieldStyle(.roundedBorder).lineLimit(1...4)
+                            .ultracodeGlow(active: MobileEfforts.isUltracode(effort))
+                        Button {
+                            store.startChat(in: project.id, message: draft, effort: effort)
+                            draft = ""
+                        } label: { Image(systemName: "arrow.up.circle.fill").font(.title2) }
+                            .disabled(draft.trimmingCharacters(in: .whitespaces).isEmpty || !store.canControl)
+                    }
                 }
             }
             Section("Sessions") {

ios/NucleicRemote/NucleicRemote/Views/Theme.swift

@@ -13,6 +13,10 @@ enum Palette {
     static let paused = Color(red: 0.62, green: 0.49, blue: 0.93)   // purple
     static let danger = Color(red: 0.92, green: 0.34, blue: 0.34)   // red
     static let neutral = Color.secondary
+    /// The ultracode (orchestration mode) signature purple — mirrors the Mac's
+    /// `AppTheme.ultracode`. Used for the effort picker's Ultracode option and the
+    /// composer's purple ring.
+    static let ultracode = Color(red: 0.55, green: 0.28, blue: 0.95)
 
     /// Dot/accent color for a session's status, refined by the last turn's disposition — a
     /// finished-the-work turn reads as "done" (success) rather than the calm "ready" accent.
@@ -113,4 +117,79 @@ extension View {
     func card(padding: CGFloat = 14) -> some View { modifier(CardBackground(padding: padding)) }
     /// Apply the teal accent app-wide.
     func nucleicTint() -> some View { tint(Palette.accent) }
+    /// Wrap a composer field in the ultracode purple ring while `active` (mirrors the Mac's
+    /// animated composer glow, lighter touch).
+    func ultracodeGlow(active: Bool, cornerRadius: CGFloat = 8) -> some View {
+        modifier(UltracodeGlowModifier(active: active, cornerRadius: cornerRadius))
+    }
+}
+
+/// The effort levels the remote offers, mirroring the Mac's `ModelCatalog.efforts` plus
+/// ultracode. `ultracodeSentinel` MUST stay equal to the host's `OrchestrationMode.effortSentinel`
+/// — it's sent verbatim over the sync wire and resolved on the host (to `xhigh` + standing
+/// consent), so a mismatch would silently disable the mode.
+enum MobileEfforts {
+    static let levels = ["low", "medium", "high", "xhigh", "max"]
+    static let ultracodeSentinel = "ultracode"
+    static let fallback = "high"
+
+    static func isUltracode(_ effort: String) -> Bool { effort == ultracodeSentinel }
+    static func displayName(_ effort: String) -> String { isUltracode(effort) ? "Ultracode" : effort }
+}
+
+/// A compact effort selector for the remote composers. Ultracode sits below the API levels,
+/// set apart with a sparkles glyph and the purple accent.
+struct EffortMenu: View {
+    @Binding var effort: String
+
+    var body: some View {
+        Menu {
+            ForEach(MobileEfforts.levels, id: \.self) { level in
+                Button { effort = level } label: {
+                    if effort == level { Label(level, systemImage: "checkmark") } else { Text(level) }
+                }
+            }
+            Divider()
+            Button { effort = MobileEfforts.ultracodeSentinel } label: {
+                Label("Ultracode", systemImage: MobileEfforts.isUltracode(effort) ? "checkmark" : "sparkles")
+            }
+        } label: {
+            HStack(spacing: 4) {
+                Image(systemName: MobileEfforts.isUltracode(effort) ? "sparkles" : "slider.horizontal.3")
+                Text(MobileEfforts.displayName(effort))
+            }
+            .font(.caption)
+            .foregroundStyle(MobileEfforts.isUltracode(effort) ? Palette.ultracode : Palette.accent)
+        }
+    }
+}
+
+/// A gentle purple ring that breathes around a composer while ultracode is selected — the
+/// remote echo of the Mac's `UltracodeGlow`. Honors Reduce Motion (holds steady).
+struct UltracodeGlowModifier: ViewModifier {
+    var active: Bool
+    var cornerRadius: CGFloat
+    @Environment(\.accessibilityReduceMotion) private var reduceMotion
+    @State private var pulsing = false
+
+    func body(content: Content) -> some View {
+        let animating = active && pulsing && !reduceMotion
+        return content
+            .overlay {
+                if active {
+                    RoundedRectangle(cornerRadius: cornerRadius, style: .continuous)
+                        .strokeBorder(Palette.ultracode.opacity(animating ? 0.9 : 0.5),
+                                      lineWidth: animating ? 1.6 : 1.2)
+                        .shadow(color: Palette.ultracode.opacity(animating ? 0.5 : 0.2),
+                                radius: animating ? 8 : 3)
+                        .animation(
+                            reduceMotion ? .default
+                                : .easeInOut(duration: 1.8).repeatForever(autoreverses: true),
+                            value: pulsing)
+                        .allowsHitTesting(false)
+                }
+            }
+            .onAppear { pulsing = active }
+            .onChange(of: active) { _, now in pulsing = now }
+    }
 }