diff --git a/packages/tui/go.mod b/packages/tui/go.mod
index 01b2947ae059..471a6b8d848b 100644
--- a/packages/tui/go.mod
+++ b/packages/tui/go.mod
@@ -68,10 +68,10 @@ require (
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.2.0
 	github.com/mattn/go-isatty v0.0.20 // indirect
-	github.com/mattn/go-runewidth v0.0.16 // indirect
+	github.com/mattn/go-runewidth v0.0.16
 	github.com/microcosm-cc/bluemonday v1.0.27 // indirect
 	github.com/muesli/cancelreader v0.2.2 // indirect
-	github.com/rivo/uniseg v0.4.7 // indirect
+	github.com/rivo/uniseg v0.4.7
 	github.com/rogpeppe/go-internal v1.14.1 // indirect
 	github.com/spf13/pflag v1.0.6 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
diff --git a/packages/tui/go.sum b/packages/tui/go.sum
index 7574855d86c1..6df82e2fe986 100644
--- a/packages/tui/go.sum
+++ b/packages/tui/go.sum
@@ -34,7 +34,7 @@ github.com/charmbracelet/glamour v0.10.0 h1:MtZvfwsYCx8jEPFJm3rIBFIMZUfUJ765oX8V
 github.com/charmbracelet/glamour v0.10.0/go.mod h1:f+uf+I/ChNmqo087elLnVdCiVgjSKWuXa/l6NU2ndYk=
 github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834 h1:ZR7e0ro+SZZiIZD7msJyA+NjkCNNavuiPBLgerbOziE=
 github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834/go.mod h1:aKC/t2arECF6rNOnaKaVU6y4t4ZeHQzqfxedE/VkVhA=
-github.com/charmbracelet/lipgloss/v2 v2.0.0-beta.1 h1:D9AJJuYTN5pvz6mpIGO1ijLKpfTYSHOtKGgwoTQ4Gog=
+github.com/charmbracelet/lipgloss/v2 v2.0.0-beta.1 h1:kU4FK3BrF9yfW4P1tT1+Ag9KVckKhkUuLTwj//7SzaA=
 github.com/charmbracelet/lipgloss/v2 v2.0.0-beta.1/go.mod h1:tRlx/Hu0lo/j9viunCN2H+Ze6JrmdjQlXUQvvArgaOc=
 github.com/charmbracelet/x/ansi v0.8.0 h1:9GTq3xq9caJW8ZrBTe0LIe2fvfLR/bYXKTx2llXn7xE=
 github.com/charmbracelet/x/ansi v0.8.0/go.mod h1:wdYl/ONOLHLIVmQaxbIYEC/cRKOQyjTkowiI4blgS9Q=
diff --git a/packages/tui/internal/theme/onedark.go b/packages/tui/internal/theme/onedark.go
new file mode 100644
index 000000000000..1d7749c93c00
--- /dev/null
+++ b/packages/tui/internal/theme/onedark.go
@@ -0,0 +1,295 @@
+package theme
+
+import (
+	"github.com/charmbracelet/lipgloss/v2"
+	"github.com/charmbracelet/lipgloss/v2/compat"
+)
+
+// OneDarkTheme implements the Theme interface with One Dark colors.
+// It provides both dark and light variants.
+type OneDarkTheme struct {
+	BaseTheme
+}
+
+// NewOneDarkTheme creates a new instance of the One Dark theme.
+func NewOneDarkTheme() *OneDarkTheme {
+	// One Dark color palette based on Zed's One Dark theme
+	// Dark mode colors - One Dark variant
+	darkStep1 := "#282c33"  // App background (editor.background)
+	darkStep2 := "#2f343e"  // Subtle background (surface.background)
+	darkStep3 := "#2e343e"  // UI element background (element.background)
+	darkStep4 := "#363c46"  // Hovered UI element background (element.hover)
+	darkStep5 := "#454a56"  // Active/Selected UI element background (element.active)
+	darkStep6 := "#464b57"  // Subtle borders and separators (border)
+	darkStep7 := "#464b57"  // UI element border and focus rings (border)
+	darkStep8 := "#47679e"  // Hovered UI element border (border.focused)
+	darkStep9 := "#74ade8"  // Solid backgrounds (text.accent)
+	darkStep10 := "#73ade9" // Hovered solid backgrounds
+	darkStep11 := "#a9afbc" // Low-contrast text (text.muted)
+	darkStep12 := "#dce0e5" // High-contrast text (text)
+
+	// Dark mode accent colors from One Dark syntax
+	darkRed := "#d07277"     // syntax.property, syntax.enum
+	darkOrange := "#bf956a"  // syntax.number, syntax.boolean
+	darkYellow := "#dec184"  // syntax.constant
+	darkGreen := "#a1c181"   // syntax.string
+	darkCyan := "#6eb4bf"    // syntax.operator, syntax.type
+	darkBlue := darkStep9    // Using step 9 for primary
+	darkPurple := "#b477cf"  // syntax.keyword
+
+	// Light mode colors - One Light variant
+	lightStep1 := "#fafafa"  // App background (editor.background)
+	lightStep2 := "#ebebec"  // Subtle background (surface.background)
+	lightStep3 := "#ebebec"  // UI element background (element.background)
+	lightStep4 := "#dfdfe0"  // Hovered UI element background (element.hover)
+	lightStep5 := "#cacaca"  // Active/Selected UI element background (element.active)
+	lightStep6 := "#c9c9ca"  // Subtle borders and separators (border)
+	lightStep7 := "#c9c9ca"  // UI element border and focus rings (border)
+	lightStep8 := "#7d82e8"  // Hovered UI element border (border.focused)
+	lightStep9 := "#5c78e2"  // Solid backgrounds (text.accent)
+	lightStep10 := "#5b79e3" // Hovered solid backgrounds
+	lightStep11 := "#58585a" // Low-contrast text (text.muted)
+	lightStep12 := "#242529" // High-contrast text (text)
+
+	// Light mode accent colors from One Light syntax
+	lightRed := "#d36151"    // syntax.property, syntax.enum
+	lightOrange := "#ad6e25" // syntax.number, syntax.boolean
+	lightYellow := "#a48819" // syntax.constant (modified/warning)
+	lightGreen := "#669f59"  // syntax.string
+	lightCyan := "#3a82b7"   // syntax.operator, syntax.type
+	lightBlue := lightStep9  // Using step 9 for primary
+	lightPurple := "#a449ab" // syntax.keyword
+
+	// Unused variables to avoid compiler errors (these could be used for hover states)
+	_ = darkStep4
+	_ = darkStep5
+	_ = darkStep10
+	_ = lightStep4
+	_ = lightStep5
+	_ = lightStep10
+
+	theme := &OneDarkTheme{}
+
+	// Base colors
+	theme.PrimaryColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkBlue),
+		Light: lipgloss.Color(lightBlue),
+	}
+	theme.SecondaryColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkPurple),
+		Light: lipgloss.Color(lightPurple),
+	}
+	theme.AccentColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkOrange),
+		Light: lipgloss.Color(lightOrange),
+	}
+
+	// Status colors
+	theme.ErrorColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkRed),
+		Light: lipgloss.Color(lightRed),
+	}
+	theme.WarningColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkOrange),
+		Light: lipgloss.Color(lightOrange),
+	}
+	theme.SuccessColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkGreen),
+		Light: lipgloss.Color(lightGreen),
+	}
+	theme.InfoColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkBlue),
+		Light: lipgloss.Color(lightBlue),
+	}
+
+	// Text colors
+	theme.TextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep12),
+		Light: lipgloss.Color(lightStep12),
+	}
+	theme.TextMutedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep11),
+		Light: lipgloss.Color(lightStep11),
+	}
+
+	// Background colors
+	theme.BackgroundColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep1),
+		Light: lipgloss.Color(lightStep1),
+	}
+	theme.BackgroundSubtleColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep2),
+		Light: lipgloss.Color(lightStep2),
+	}
+	theme.BackgroundElementColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep3),
+		Light: lipgloss.Color(lightStep3),
+	}
+
+	// Border colors
+	theme.BorderColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep7),
+		Light: lipgloss.Color(lightStep7),
+	}
+	theme.BorderActiveColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep8),
+		Light: lipgloss.Color(lightStep8),
+	}
+	theme.BorderSubtleColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep6),
+		Light: lipgloss.Color(lightStep6),
+	}
+
+	// Diff view colors using One Dark version control colors
+	theme.DiffAddedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#27a657"), // version_control.added
+		Light: lipgloss.Color("#27a657"),
+	}
+	theme.DiffRemovedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#e06c76"), // version_control.deleted
+		Light: lipgloss.Color("#e06c76"),
+	}
+	theme.DiffContextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#acb2be"), // editor.foreground
+		Light: lipgloss.Color("#242529"), // editor.foreground (light)
+	}
+	theme.DiffHunkHeaderColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#a9afbc"), // text.muted
+		Light: lipgloss.Color("#58585a"), // text.muted (light)
+	}
+	theme.DiffHighlightAddedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#a1c181"), // created color
+		Light: lipgloss.Color("#669f59"), // created color (light)
+	}
+	theme.DiffHighlightRemovedColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#d07277"), // deleted color
+		Light: lipgloss.Color("#d36151"), // deleted color (light)
+	}
+	theme.DiffAddedBgColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#a1c1811a"), // created.background
+		Light: lipgloss.Color("#dfeadb"), // created.background (light)
+	}
+	theme.DiffRemovedBgColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#d072771a"), // deleted.background
+		Light: lipgloss.Color("#fbdfd9"), // deleted.background (light)
+	}
+	theme.DiffContextBgColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep2),
+		Light: lipgloss.Color(lightStep2),
+	}
+	theme.DiffLineNumberColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#4e5a5f"), // editor.line_number
+		Light: lipgloss.Color("#b4b4bb"), // editor.line_number (light)
+	}
+	theme.DiffAddedLineNumberBgColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#38482f"), // created.border
+		Light: lipgloss.Color("#c8dcc1"), // created.border (light)
+	}
+	theme.DiffRemovedLineNumberBgColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color("#4c2b2c"), // deleted.border
+		Light: lipgloss.Color("#f6c6bd"), // deleted.border (light)
+	}
+
+	// Markdown colors
+	theme.MarkdownTextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep12),
+		Light: lipgloss.Color(lightStep12),
+	}
+	theme.MarkdownHeadingColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkPurple),
+		Light: lipgloss.Color(lightPurple),
+	}
+	theme.MarkdownLinkColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkBlue),
+		Light: lipgloss.Color(lightBlue),
+	}
+	theme.MarkdownLinkTextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkCyan),
+		Light: lipgloss.Color(lightCyan),
+	}
+	theme.MarkdownCodeColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkGreen),
+		Light: lipgloss.Color(lightGreen),
+	}
+	theme.MarkdownBlockQuoteColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkYellow),
+		Light: lipgloss.Color(lightYellow),
+	}
+	theme.MarkdownEmphColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkYellow),
+		Light: lipgloss.Color(lightYellow),
+	}
+	theme.MarkdownStrongColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkOrange),
+		Light: lipgloss.Color(lightOrange),
+	}
+	theme.MarkdownHorizontalRuleColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep11),
+		Light: lipgloss.Color(lightStep11),
+	}
+	theme.MarkdownListItemColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkBlue),
+		Light: lipgloss.Color(lightBlue),
+	}
+	theme.MarkdownListEnumerationColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkCyan),
+		Light: lipgloss.Color(lightCyan),
+	}
+	theme.MarkdownImageColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkBlue),
+		Light: lipgloss.Color(lightBlue),
+	}
+	theme.MarkdownImageTextColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkCyan),
+		Light: lipgloss.Color(lightCyan),
+	}
+	theme.MarkdownCodeBlockColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep12),
+		Light: lipgloss.Color(lightStep12),
+	}
+
+	// Syntax highlighting colors
+	theme.SyntaxCommentColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep11),
+		Light: lipgloss.Color(lightStep11),
+	}
+	theme.SyntaxKeywordColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkPurple),
+		Light: lipgloss.Color(lightPurple),
+	}
+	theme.SyntaxFunctionColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkBlue),
+		Light: lipgloss.Color(lightBlue),
+	}
+	theme.SyntaxVariableColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkRed),
+		Light: lipgloss.Color(lightRed),
+	}
+	theme.SyntaxStringColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkGreen),
+		Light: lipgloss.Color(lightGreen),
+	}
+	theme.SyntaxNumberColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkOrange),
+		Light: lipgloss.Color(lightOrange),
+	}
+	theme.SyntaxTypeColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkYellow),
+		Light: lipgloss.Color(lightYellow),
+	}
+	theme.SyntaxOperatorColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkCyan),
+		Light: lipgloss.Color(lightCyan),
+	}
+	theme.SyntaxPunctuationColor = compat.AdaptiveColor{
+		Dark:  lipgloss.Color(darkStep12),
+		Light: lipgloss.Color(lightStep12),
+	}
+
+	return theme
+}
+
+func init() {
+	// Register the One Dark theme with the theme manager
+	RegisterTheme("onedark", NewOneDarkTheme())
+}