diff --git a/Sources/Core/Network/FrameCodec.swift b/Sources/Core/Network/FrameCodec.swift
index fc444ba..12fc301 100644
--- a/Sources/Core/Network/FrameCodec.swift
+++ b/Sources/Core/Network/FrameCodec.swift
@@ -93,11 +93,14 @@ public enum ClientToServer: Sendable {
     case paste(data: String)
     /// Request a full ANSI snapshot of the current pane.
     case snapshotRequest
+    /// Notify the sidecar of the client's terminal dimensions so tmux can
+    /// resize the window to match. Send on connect and on every layout change.
+    case resize(cols: Int, rows: Int)
 }
 
 extension ClientToServer: Encodable {
     private enum CodingKeys: String, CodingKey {
-        case type, lastSeq, name, data
+        case type, lastSeq, name, data, cols, rows
     }
 
     public func encode(to encoder: any Encoder) throws {
@@ -123,6 +126,11 @@ extension ClientToServer: Encodable {
 
         case .snapshotRequest:
             try c.encode("snapshot-request", forKey: .type)
+
+        case .resize(let cols, let rows):
+            try c.encode("resize", forKey: .type)
+            try c.encode(cols, forKey: .cols)
+            try c.encode(rows, forKey: .rows)
         }
     }
 }
diff --git a/Sources/UI/Terminal/MainTerminalView.swift b/Sources/UI/Terminal/MainTerminalView.swift
index 3c3fda9..b2c038d 100644
--- a/Sources/UI/Terminal/MainTerminalView.swift
+++ b/Sources/UI/Terminal/MainTerminalView.swift
@@ -19,9 +19,6 @@ struct MainTerminalView: View {
         VStack(spacing: 0) {
             // ── Status bar ──────────────────────────────────────────
             HStack {
-                Circle()
-                    .fill(connection != nil ? Color.green : Color.orange)
-                    .frame(width: 8, height: 8)
                 Text(statusText)
                     .font(.caption.monospaced())
                     .foregroundStyle(.secondary)
@@ -85,10 +82,23 @@ struct MainTerminalView: View {
                 }
                 .store(in: &cancellables)
 
+            // Wire resize callback — fires on layout + font changes.
+            terminalVC.onResize = { [weak conn] cols, rows in
+                guard let conn else { return }
+                Task { try? await conn.send(.resize(cols: cols, rows: rows)) }
+            }
+
             connection = conn
             await conn.resume(from: conn.scrollback.sizeBytes > 0
                 ? ResumeCursor().lastSeq(for: sessionId)
                 : nil)
+
+            // Send the current terminal size immediately after connecting
+            // so tmux resizes before the first output frame arrives.
+            let (cols, rows) = terminalVC.terminalSize
+            if cols > 0 && rows > 0 {
+                try? await conn.send(.resize(cols: cols, rows: rows))
+            }
         } catch {
             statusText = "Error: \(error.localizedDescription)"
         }
diff --git a/Sources/UI/Terminal/TerminalViewController.swift b/Sources/UI/Terminal/TerminalViewController.swift
index d23adad..36a17b8 100644
--- a/Sources/UI/Terminal/TerminalViewController.swift
+++ b/Sources/UI/Terminal/TerminalViewController.swift
@@ -31,6 +31,10 @@ public final class TerminalViewController: UIViewController {
     /// forwarded to the remote PTY (wired by T-2.5).
     public var onInput: ((Data) -> Void)?
 
+    /// Called when SwiftTerm recalculates its column/row count (layout,
+    /// font change, rotation). Forward this to the sidecar so tmux resizes.
+    public var onResize: ((Int, Int) -> Void)?
+
     // MARK: View lifecycle
 
     public override func viewDidLoad() {
@@ -139,8 +143,11 @@ extension TerminalViewController: TerminalViewDelegate {
     // MARK: Required — size change notification
 
     public nonisolated func sizeChanged(source: TerminalView, newCols: Int, newRows: Int) {
-        // No-op in T-2.3; the stream layer (T-2.5) will negotiate PTY size
-        // with the sidecar when it subscribes to this controller.
+        // Propagate to whoever manages the sidecar connection so they can
+        // call `tmux resize-window` and keep line-wrapping in sync.
+        MainActor.assumeIsolated {
+            onResize?(newCols, newRows)
+        }
     }
 
     // MARK: Required — title change