diff --git a/packages/opencode/src/cli/cmd/run/runtime.boot.ts b/packages/opencode/src/cli/cmd/run/runtime.boot.ts
index b1f62178460e..fa9033a00ce4 100644
--- a/packages/opencode/src/cli/cmd/run/runtime.boot.ts
+++ b/packages/opencode/src/cli/cmd/run/runtime.boot.ts
@@ -82,6 +82,7 @@ function runTuiConfig(config: Config | undefined): RunTuiConfig {
     keybinds: config.keybinds,
     leader_timeout: config.leader_timeout,
     diff_style: config.diff_style ?? "auto",
+    input: config.input,
   }
 }
 
diff --git a/packages/opencode/src/cli/cmd/run/types.ts b/packages/opencode/src/cli/cmd/run/types.ts
index a914922e4870..9cfd1ef01f8b 100644
--- a/packages/opencode/src/cli/cmd/run/types.ts
+++ b/packages/opencode/src/cli/cmd/run/types.ts
@@ -286,7 +286,7 @@ export type QuestionReply = Parameters<OpencodeClient["question"]["reply"]>[0]
 
 export type QuestionReject = Parameters<OpencodeClient["question"]["reject"]>[0]
 
-export type RunTuiConfig = Pick<TuiConfig.Resolved, "keybinds" | "leader_timeout" | "diff_style">
+export type RunTuiConfig = Pick<TuiConfig.Resolved, "keybinds" | "leader_timeout" | "diff_style" | "input">
 
 // Lifecycle phase of a scrollback entry. "start" opens the entry, "progress"
 // appends content (coalesced in the footer queue), "final" closes it.
diff --git a/packages/tui/src/config/index.tsx b/packages/tui/src/config/index.tsx
index bde0bfb0718a..6e4c7efa956b 100644
--- a/packages/tui/src/config/index.tsx
+++ b/packages/tui/src/config/index.tsx
@@ -58,6 +58,16 @@ export const Prompt = Schema.Struct({
   }),
 }).annotate({ description: "Prompt size settings" })
 
+export const Input = Schema.Struct({
+  line_discard: Schema.optional(Schema.Literals(["bash", "zsh"])).annotate({
+    description: [
+      "What input_delete_to_line_start (ctrl+u) deletes in the prompt and every other text field:",
+      "'bash' (default) from the cursor back to the start of its line, 'zsh' that whole line wherever",
+      "the cursor is. In a multi-line prompt only the cursor's line, not the whole prompt",
+    ].join(" "),
+  }),
+}).annotate({ description: "Text field editing settings" })
+
 export const Info = Schema.Struct({
   $schema: Schema.optional(Schema.String),
   theme: Schema.optional(Schema.String),
@@ -67,6 +77,7 @@ export const Info = Schema.Struct({
   leader_timeout: Schema.optional(LeaderTimeout),
   attention: Schema.optional(Attention),
   prompt: Schema.optional(Prompt),
+  input: Schema.optional(Input),
   scroll_speed: Schema.optional(ScrollSpeed).annotate({ description: "TUI scroll speed" }),
   scroll_acceleration: Schema.optional(ScrollAcceleration),
   diff_style: Schema.optional(DiffStyle),
diff --git a/packages/tui/src/keymap.tsx b/packages/tui/src/keymap.tsx
index 8d0aefc8f5dc..f996e62e1d2f 100644
--- a/packages/tui/src/keymap.tsx
+++ b/packages/tui/src/keymap.tsx
@@ -16,6 +16,7 @@ import { KeymapProvider, useKeymap, useKeymapSelector, useBindings } from "@open
 import { createMemo, type Accessor } from "solid-js"
 import { useTuiConfig } from "./config"
 import { TuiKeybind } from "./config/keybind"
+import { discardLine, type LineDiscard } from "./util/line-discard"
 
 export const LEADER_TOKEN = "leader"
 export const OPENCODE_BASE_MODE = "base"
@@ -42,7 +43,7 @@ type BindingLookup = {
   gather(name: string, commands: readonly string[]): readonly Binding<Renderable, KeyEvent>[]
 }
 type FormatConfig = { keybinds: BindingLookup }
-type ResolvedKeymapConfig = FormatConfig & { leader_timeout: number }
+type ResolvedKeymapConfig = FormatConfig & { leader_timeout: number; input?: { line_discard?: LineDiscard } }
 
 const modeStacks = new WeakMap<OpenTuiKeymap, OpencodeModeStack>()
 
@@ -172,6 +173,33 @@ const inputCommands = [
   "input.submit",
 ] as const
 
+// Replaces the textarea's delete-to-line-start command, which a later layer
+// runs first, with one that follows input.line_discard. A single-line <input>
+// handles ctrl+u itself, so its own layer routes input_delete_to_line_start
+// to the same command while one has focus.
+function registerLineDiscardCommand(keymap: OpenTuiKeymap, renderer: CliRenderer, config: ResolvedKeymapConfig) {
+  const offCommand = keymap.registerLayer({
+    commands: [
+      {
+        name: "input.delete.to.line.start",
+        run() {
+          const editor = renderer.currentFocusedEditor
+          if (!editor || editor.isDestroyed) return false
+          return discardLine(editor, config.input?.line_discard)
+        },
+      },
+    ],
+  })
+  const offInputBindings = keymap.registerLayer({
+    enabled: () => renderer.currentFocusedEditor instanceof InputRenderable,
+    bindings: config.keybinds.gather("input-line-discard", ["input.delete.to.line.start"]),
+  })
+  return () => {
+    offInputBindings()
+    offCommand()
+  }
+}
+
 function hasManagedTextareaFocus(renderer: CliRenderer) {
   const editor = renderer.currentFocusedEditor
   return editor instanceof TextareaRenderable && !(editor instanceof InputRenderable)
@@ -230,8 +258,10 @@ export function registerOpencodeKeymap(keymap: OpenTuiKeymap, renderer: CliRende
     enabled: () => hasManagedTextareaFocus(renderer),
     bindings: config.keybinds.gather("input", inputCommands),
   })
+  const offLineDiscard = registerLineDiscardCommand(keymap, renderer, config)
 
   return () => {
+    offLineDiscard()
     offInputBindings()
     offBackspace()
     offEscape()
diff --git a/packages/tui/src/util/line-discard.ts b/packages/tui/src/util/line-discard.ts
new file mode 100644
index 000000000000..dde2884812d2
--- /dev/null
+++ b/packages/tui/src/util/line-discard.ts
@@ -0,0 +1,15 @@
+import type { EditBufferRenderable } from "@opentui/core"
+
+export type LineDiscard = "bash" | "zsh"
+
+// input_delete_to_line_start (ctrl+u) in every text field. 'bash' deletes from
+// the caret back to the start of its logical line, as readline's
+// unix-line-discard does; 'zsh' deletes that whole line wherever the caret is,
+// as zsh's kill-whole-line does. Either way the line itself stays: a press at
+// the start of a line ('bash'), or on an empty one ('zsh'), joins it to the
+// previous line, as opentui's deleteToLineStart does. The deletion goes
+// through the edit buffer, so input_undo restores it.
+export function discardLine(editor: EditBufferRenderable, mode: LineDiscard | undefined) {
+  if (mode === "zsh") editor.setCursor(editor.logicalCursor.row, editor.editBuffer.getEOL().col)
+  return editor.deleteToLineStart()
+}
diff --git a/packages/tui/test/keymap.test.tsx b/packages/tui/test/keymap.test.tsx
index b0eed3081248..7985e59ca17e 100644
--- a/packages/tui/test/keymap.test.tsx
+++ b/packages/tui/test/keymap.test.tsx
@@ -4,8 +4,10 @@ import { createBindingLookup } from "@opentui/keymap/extras"
 import { testRender, useRenderer } from "@opentui/solid"
 import { expect, test } from "bun:test"
 import { onCleanup } from "solid-js"
+import type { InputRenderable, TextareaRenderable } from "@opentui/core"
 import { TuiKeybind } from "../src/config/keybind"
 import { getOpencodeModeStack, OPENCODE_BASE_MODE, OpencodeKeymapProvider, registerOpencodeKeymap } from "../src/keymap"
+import type { LineDiscard } from "../src/util/line-discard"
 
 function createResolvedKeymapConfig(input: TuiKeybind.KeybindOverrides = {}) {
   const keybinds = TuiKeybind.parse(input)
@@ -139,3 +141,69 @@ test("mode-less bindings stay active when opencode mode changes", async () => {
     app.renderer.destroy()
   }
 })
+
+test("ctrl+u follows input.line_discard in a textarea, on the caret's line only, and in an input", async () => {
+  async function run(mode: LineDiscard | undefined, field: "textarea" | "input", text: string, caret: number) {
+    let editor: TextareaRenderable | InputRenderable | undefined
+
+    function Harness() {
+      const renderer = useRenderer()
+      const keymap = createDefaultOpenTuiKeymap(renderer)
+      const offKeymap = registerOpencodeKeymap(keymap, renderer, {
+        ...createResolvedKeymapConfig(),
+        input: { line_discard: mode },
+      })
+      onCleanup(offKeymap)
+      const ref = (el: TextareaRenderable) => (editor = el)
+
+      return (
+        <OpencodeKeymapProvider keymap={keymap}>
+          {field === "textarea" ? (
+            <textarea ref={ref} focused initialValue={text} />
+          ) : (
+            <input ref={ref} focused value={text} />
+          )}
+        </OpencodeKeymapProvider>
+      )
+    }
+
+    const app = await testRender(() => <Harness />)
+    try {
+      if (!editor) throw new Error(`${field} did not mount`)
+      editor.cursorOffset = caret
+      app.renderer.stdin.emit("data", Buffer.from("\x15"))
+      await Bun.sleep(50)
+      const after = { text: editor.plainText, caret: editor.cursorOffset }
+      editor.undo()
+      return { ...after, undone: editor.plainText }
+    } finally {
+      app.renderer.destroy()
+    }
+  }
+
+  expect(await run(undefined, "textarea", "hello world", 5)).toEqual({
+    text: " world",
+    caret: 0,
+    undone: "hello world",
+  })
+  expect(await run("bash", "textarea", "hello world", 5)).toEqual({ text: " world", caret: 0, undone: "hello world" })
+  expect(await run("zsh", "textarea", "hello world", 5)).toEqual({ text: "", caret: 0, undone: "hello world" })
+  expect(await run("bash", "textarea", "first\nhello world\nlast", 11)).toEqual({
+    text: "first\n world\nlast",
+    caret: 6,
+    undone: "first\nhello world\nlast",
+  })
+  expect(await run("zsh", "textarea", "first\nhello world\nlast", 11)).toEqual({
+    text: "first\n\nlast",
+    caret: 6,
+    undone: "first\nhello world\nlast",
+  })
+  // A second press on the emptied line joins it to the previous one.
+  expect(await run("zsh", "textarea", "first\n\nlast", 6)).toEqual({
+    text: "first\nlast",
+    caret: 5,
+    undone: "first\n\nlast",
+  })
+  expect(await run("bash", "input", "hello world", 5)).toEqual({ text: " world", caret: 0, undone: "hello world" })
+  expect(await run("zsh", "input", "hello world", 5)).toEqual({ text: "", caret: 0, undone: "hello world" })
+})
diff --git a/packages/web/src/content/docs/tui.mdx b/packages/web/src/content/docs/tui.mdx
index 0351c46cde10..e21615bbef68 100644
--- a/packages/web/src/content/docs/tui.mdx
+++ b/packages/web/src/content/docs/tui.mdx
@@ -409,6 +409,7 @@ This is separate from `opencode.json`, which configures server/runtime behavior.
 - `scroll_acceleration.enabled` - Enable macOS-style scroll acceleration for smooth, natural scrolling. When enabled, scroll speed increases with rapid scrolling gestures and stays precise for slower movements. **This setting takes precedence over `scroll_speed` and overrides it when enabled.**
 - `scroll_speed` - Controls how fast the TUI scrolls when using scroll commands (minimum: `0.001`, supports decimal values). Defaults to `3`. **Note: This is ignored if `scroll_acceleration.enabled` is set to `true`.**
 - `diff_style` - Controls diff rendering. `"auto"` adapts to terminal width, `"stacked"` always shows a single-column layout.
+- `input.line_discard` - What <kbd>ctrl+u</kbd> (`input_delete_to_line_start`) deletes in the prompt and every other text field: `"bash"` (default) deletes from the cursor back to the start of its line, as bash does; `"zsh"` deletes the whole line wherever the cursor is, as zsh does. In a multi-line prompt it is the cursor's line, never the rest of the prompt; on a line that is already empty, or with the cursor at its start under `"bash"`, it joins the line to the one above. <kbd>ctrl+k</kbd> (`input_delete_to_line_end`) and `input_delete_line` are unchanged, and `input_undo` brings the text back.
 - `cursor` - Controls the terminal cursor in TUI input fields. `style` defaults to `"block"`, can be `"underline"`, `"line"`, or `"default"`; `blinking` defaults to `true`. When `style` is `"default"`, the terminal default cursor is restored, so `blinking` has no effect.
 - `mouse` - Enable or disable mouse capture in the TUI (default: `true`). When disabled, the terminal's native mouse selection/scrolling behavior is preserved.
 - `attention` - Configures TUI desktop notifications and sounds. Disabled by default.