Add configurable sidebar workspace font size

Sources/GhosttyConfig.swift

@@ -13,10 +13,14 @@ struct GhosttyConfig {
 
     private static let loadCacheLock = NSLock()
     private static var cachedConfigsByColorScheme: [ColorSchemePreference: GhosttyConfig] = [:]
+    static let defaultSidebarFontSize: CGFloat = 12.5
+    static let minSidebarFontSize: CGFloat = 10
+    static let maxSidebarFontSize: CGFloat = 20
 
     var fontFamily: String = "Menlo"
     var fontSize: CGFloat = 12
     var surfaceTabBarFontSize: CGFloat = 11
+    var sidebarFontSize: CGFloat = Self.defaultSidebarFontSize
     var theme: String?
     var workingDirectory: String?
     // Ghostty measures scrollback-limit in bytes, not lines.
@@ -394,6 +398,10 @@ struct GhosttyConfig {
                     if let size = Double(value) {
                         surfaceTabBarFontSize = CGFloat(size)
                     }
+                case "sidebar-font-size":
+                    if let size = Double(value), size.isFinite {
+                        sidebarFontSize = Self.clampedSidebarFontSize(CGFloat(size))
+                    }
                 case "theme":
                     theme = value
                     if let preferredColorScheme {
@@ -655,6 +663,11 @@ struct GhosttyConfig {
         return parsed
     }
 
+    static func clampedSidebarFontSize(_ value: CGFloat) -> CGFloat {
+        guard value.isFinite else { return defaultSidebarFontSize }
+        return min(max(value, minSidebarFontSize), maxSidebarFontSize)
+    }
+
     private static func parseBackgroundBlur(_ value: String) -> GhosttyBackgroundBlur? {
         switch value {
         case "false", "0":

Sources/ShortcutHintPill.swift

@@ -70,11 +70,12 @@ extension View {
         text: String?,
         emphasis: Double,
         offsetX: Double,
-        offsetY: Double
+        offsetY: Double,
+        fontSize: CGFloat = 10
     ) -> some View {
         overlay(alignment: .topTrailing) {
             if let text {
-                ShortcutHintPill(text: text, fontSize: 10, emphasis: emphasis)
+                ShortcutHintPill(text: text, fontSize: fontSize, emphasis: emphasis)
                     .offset(
                         x: ShortcutHintDebugSettings.clamped(offsetX),
                         y: ShortcutHintDebugSettings.clamped(offsetY)

Sources/Sidebar/SidebarDirectoryText.swift

@@ -9,25 +9,26 @@ import SwiftUI
 struct SidebarDirectoryText: View {
     let candidates: [String]
     let color: Color
+    var fontScale: CGFloat = 1
 
     var body: some View {
         if candidates.count <= 1 {
             Text(candidates.first ?? "")
-                .font(.system(size: 10, design: .monospaced))
+                .font(.system(size: 10 * fontScale, design: .monospaced))
                 .foregroundColor(color)
                 .lineLimit(1)
                 .truncationMode(.tail)
         } else {
             ViewThatFits(in: .horizontal) {
                 ForEach(Array(candidates.dropLast().enumerated()), id: \.offset) { _, candidate in
                     Text(candidate)
-                        .font(.system(size: 10, design: .monospaced))
+                        .font(.system(size: 10 * fontScale, design: .monospaced))
                         .foregroundColor(color)
                         .lineLimit(1)
                         .fixedSize(horizontal: true, vertical: false)
                 }
                 Text(candidates.last ?? "")
-                    .font(.system(size: 10, design: .monospaced))
+                    .font(.system(size: 10 * fontScale, design: .monospaced))
                     .foregroundColor(color)
                     .lineLimit(1)
                     .truncationMode(.tail)

cmuxTests/GhosttyConfigTests.swift

@@ -4293,6 +4293,76 @@ final class SidebarBackgroundConfigTests: XCTestCase {
     }
 }
 
+final class SidebarFontSizeConfigTests: XCTestCase {
+    func testDefaultSidebarFontSizeMatchesSidebarTitleBaseline() {
+        let config = GhosttyConfig()
+
+        XCTAssertEqual(config.sidebarFontSize, 12.5, accuracy: 0.0001)
+        XCTAssertEqual(config.sidebarFontSize, GhosttyConfig.defaultSidebarFontSize, accuracy: 0.0001)
+    }
+
+    func testParseSidebarFontSizeIntegerValue() {
+        var config = GhosttyConfig()
+
+        config.parse("sidebar-font-size = 14")
+
+        XCTAssertEqual(config.sidebarFontSize, 14, accuracy: 0.0001)
+    }
+
+    func testParseSidebarFontSizeFractionalValue() {
+        var config = GhosttyConfig()
+
+        config.parse("sidebar-font-size = 13.75")
+
+        XCTAssertEqual(config.sidebarFontSize, 13.75, accuracy: 0.0001)
+    }
+
+    func testParseSidebarFontSizeClampsBelowMinimum() {
+        var config = GhosttyConfig()
+
+        config.parse("sidebar-font-size = 4")
+
+        XCTAssertEqual(config.sidebarFontSize, GhosttyConfig.minSidebarFontSize, accuracy: 0.0001)
+    }
+
+    func testParseSidebarFontSizeClampsAboveMaximum() {
+        var config = GhosttyConfig()
+
+        config.parse("sidebar-font-size = 48")
+
+        XCTAssertEqual(config.sidebarFontSize, GhosttyConfig.maxSidebarFontSize, accuracy: 0.0001)
+    }
+
+    func testParseSidebarFontSizeIgnoresInvalidAndNonFiniteValues() {
+        var config = GhosttyConfig()
+
+        config.parse("sidebar-font-size = 14")
+        config.parse(
+            """
+            sidebar-font-size = not-a-number
+            sidebar-font-size = nan
+            sidebar-font-size = inf
+            """
+        )
+
+        XCTAssertEqual(config.sidebarFontSize, 14, accuracy: 0.0001)
+    }
+
+    func testLoadUsesParsedSidebarFontSizeFromInjectedLoader() {
+        let loaded = GhosttyConfig.load(
+            preferredColorScheme: .dark,
+            useCache: false,
+            loadFromDisk: { _ in
+                var config = GhosttyConfig()
+                config.parse("sidebar-font-size = 15")
+                return config
+            }
+        )
+
+        XCTAssertEqual(loaded.sidebarFontSize, 15, accuracy: 0.0001)
+    }
+}
+
 final class ZshShellIntegrationHandoffTests: XCTestCase {
     func testGhosttyPromptHooksLoadWhenCmuxRequestsZshIntegration() throws {
         let output = try runInteractiveZsh(cmuxLoadGhosttyIntegration: true)

cmuxTests/SidebarOrderingTests.swift

@@ -115,6 +115,50 @@ final class SidebarActiveTabIndicatorSettingsTests: XCTestCase {
     }
 }
 
+final class SidebarTabItemFontScaleTests: XCTestCase {
+    func testDefaultSidebarFontScaleIsUnitScale() throws {
+        let scale = SidebarTabItemFontScale.scale(for: GhosttyConfig.defaultSidebarFontSize)
+
+        XCTAssertEqual(scale, 1, accuracy: 0.0001)
+    }
+
+    func testSidebarFontScaleIsProportionalToDefaultSidebarSize() throws {
+        let scale = SidebarTabItemFontScale.scale(for: 18)
+
+        XCTAssertEqual(
+            scale,
+            18 / GhosttyConfig.defaultSidebarFontSize,
+            accuracy: 0.0001
+        )
+    }
+
+    func testSidebarFontScaleClampsSmallSizes() throws {
+        let scale = SidebarTabItemFontScale.scale(for: 4)
+
+        XCTAssertEqual(
+            scale,
+            GhosttyConfig.minSidebarFontSize / GhosttyConfig.defaultSidebarFontSize,
+            accuracy: 0.0001
+        )
+    }
+
+    func testSidebarFontScaleClampsLargeSizes() throws {
+        let scale = SidebarTabItemFontScale.scale(for: 48)
+
+        XCTAssertEqual(
+            scale,
+            GhosttyConfig.maxSidebarFontSize / GhosttyConfig.defaultSidebarFontSize,
+            accuracy: 0.0001
+        )
+    }
+
+    func testSidebarFontScaleFallsBackToDefaultForNonFiniteValue() throws {
+        let scale = SidebarTabItemFontScale.scale(for: CGFloat.nan)
+
+        XCTAssertEqual(scale, 1, accuracy: 0.0001)
+    }
+}
+
 
 final class SidebarRemoteErrorCopySupportTests: XCTestCase {
     func testMenuLabelIsNilWhenThereAreNoErrors() {

web/app/[locale]/docs/configuration/page.tsx

@@ -273,6 +273,7 @@ touch ~/.config/ghostty/config`}</CodeBlock>
       <DocsHeading level={2} id="example-config">{t("exampleConfig")}</DocsHeading>
       <CodeBlock title="~/.config/ghostty/config" lang="ini">{`font-family = SF Mono
 font-size = 13
+sidebar-font-size = 14
 theme = One Dark
 scrollback-limit = 50000000
 split-divider-color = #3e4451