feat(tui): add native composer keymap modes (standard/vim)

codex-rs/core/config.schema.json

@@ -1370,6 +1370,15 @@
           "description": "Enable animations (welcome screen, shimmer effects, spinners). Defaults to `true`.",
           "type": "boolean"
         },
+        "keymap": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/TuiKeymap"
+            }
+          ],
+          "default": "standard",
+          "description": "Composer input keymap mode.\n\n- `standard` (default): current non-modal editing behavior. - `vim`: vim-style modal editing in the composer input."
+        },
         "notification_method": {
           "allOf": [
             {
@@ -1409,6 +1418,13 @@
       },
       "type": "object"
     },
+    "TuiKeymap": {
+      "enum": [
+        "standard",
+        "vim"
+      ],
+      "type": "string"
+    },
     "UriBasedFileOpener": {
       "oneOf": [
         {

codex-rs/core/src/config/mod.rs

@@ -20,6 +20,7 @@ use crate::config::types::ShellEnvironmentPolicy;
 use crate::config::types::ShellEnvironmentPolicyToml;
 use crate::config::types::SkillsConfig;
 use crate::config::types::Tui;
+use crate::config::types::TuiKeymap;
 use crate::config::types::UriBasedFileOpener;
 use crate::config::types::WindowsSandboxModeToml;
 use crate::config::types::WindowsToml;
@@ -281,6 +282,9 @@ pub struct Config {
     /// Syntax highlighting theme override (kebab-case name).
     pub tui_theme: Option<String>,
 
+    /// Composer input keymap mode for the TUI.
+    pub tui_keymap: TuiKeymap,
+
     /// The directory that should be treated as the current working directory
     /// for the session. All relative paths inside the business-logic layer are
     /// resolved against this path.
@@ -2124,6 +2128,7 @@ impl Config {
                 .unwrap_or_default(),
             tui_status_line: cfg.tui.as_ref().and_then(|t| t.status_line.clone()),
             tui_theme: cfg.tui.as_ref().and_then(|t| t.theme.clone()),
+            tui_keymap: cfg.tui.as_ref().map(|t| t.keymap).unwrap_or_default(),
             otel: {
                 let t: OtelConfigToml = cfg.otel.unwrap_or_default();
                 let log_user_prompt = t.log_user_prompt.unwrap_or(false);
@@ -2546,6 +2551,44 @@ theme = "dracula"
         assert_eq!(parsed.tui.as_ref().and_then(|t| t.theme.as_deref()), None);
     }
 
+    #[test]
+    fn tui_keymap_defaults_to_standard() {
+        let cfg = r#"
+[tui]
+"#;
+        let parsed =
+            toml::from_str::<ConfigToml>(cfg).expect("TOML deserialization should succeed");
+        assert_eq!(
+            parsed.tui.as_ref().map(|t| t.keymap),
+            Some(TuiKeymap::Standard),
+        );
+    }
+
+    #[test]
+    fn tui_keymap_deserializes_vim() {
+        let cfg = r#"
+[tui]
+keymap = "vim"
+"#;
+        let parsed =
+            toml::from_str::<ConfigToml>(cfg).expect("TOML deserialization should succeed");
+        assert_eq!(parsed.tui.as_ref().map(|t| t.keymap), Some(TuiKeymap::Vim));
+    }
+
+    #[test]
+    fn tui_keymap_invalid_value_errors() {
+        let cfg = r#"
+[tui]
+keymap = "bad"
+"#;
+        let err = toml::from_str::<ConfigToml>(cfg).expect_err("invalid keymap should fail");
+        let msg = err.to_string();
+        assert!(
+            msg.contains("keymap"),
+            "expected error mentioning keymap, got: {msg}"
+        );
+    }
+
     #[test]
     fn tui_config_missing_notifications_field_defaults_to_enabled() {
         let cfg = r#"
@@ -2566,6 +2609,7 @@ theme = "dracula"
                 alternate_screen: AltScreenMode::Auto,
                 status_line: None,
                 theme: None,
+                keymap: TuiKeymap::Standard,
             }
         );
     }
@@ -4676,6 +4720,7 @@ model_verbosity = "high"
                 tui_alternate_screen: AltScreenMode::Auto,
                 tui_status_line: None,
                 tui_theme: None,
+                tui_keymap: TuiKeymap::Standard,
                 otel: OtelConfig::default(),
             },
             o3_profile_config
@@ -4799,6 +4844,7 @@ model_verbosity = "high"
             tui_alternate_screen: AltScreenMode::Auto,
             tui_status_line: None,
             tui_theme: None,
+            tui_keymap: TuiKeymap::Standard,
             otel: OtelConfig::default(),
         };
 
@@ -4920,6 +4966,7 @@ model_verbosity = "high"
             tui_alternate_screen: AltScreenMode::Auto,
             tui_status_line: None,
             tui_theme: None,
+            tui_keymap: TuiKeymap::Standard,
             otel: OtelConfig::default(),
         };
 
@@ -5027,6 +5074,7 @@ model_verbosity = "high"
             tui_alternate_screen: AltScreenMode::Auto,
             tui_status_line: None,
             tui_theme: None,
+            tui_keymap: TuiKeymap::Standard,
             otel: OtelConfig::default(),
         };
 

codex-rs/core/src/config/types.rs

@@ -639,6 +639,14 @@ impl fmt::Display for NotificationMethod {
     }
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq, JsonSchema, Default)]
+#[serde(rename_all = "lowercase")]
+pub enum TuiKeymap {
+    #[default]
+    Standard,
+    Vim,
+}
+
 /// Collection of settings that are specific to the TUI.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, JsonSchema)]
 #[schemars(deny_unknown_fields)]
@@ -688,6 +696,13 @@ pub struct Tui {
     /// Use `/theme` in the TUI or see `$CODEX_HOME/themes` for custom themes.
     #[serde(default)]
     pub theme: Option<String>,
+
+    /// Composer input keymap mode.
+    ///
+    /// - `standard` (default): current non-modal editing behavior.
+    /// - `vim`: vim-style modal editing in the composer input.
+    #[serde(default)]
+    pub keymap: TuiKeymap,
 }
 
 const fn default_true() -> bool {

codex-rs/tui/src/bottom_pane/chat_composer.rs

@@ -109,6 +109,12 @@
 //! edits and renders a placeholder prompt instead of the editable textarea. This is part of the
 //! overall state machine, since it affects which transitions are even possible from a given UI
 //! state.
+//!
+//! # Edit Modes
+//!
+//! The composer supports Emacs-style input (default) and Vim-style modal input. Vim mode uses the
+//! textarea's normal/insert states; paste-burst detection is disabled while in Vim normal mode so
+//! rapid command keystrokes are not buffered as paste.
 use crate::bottom_pane::footer::mode_indicator_line;
 use crate::bottom_pane::selection_popup_common::truncate_line_with_ellipsis_if_overflow;
 use crate::key_hint;
@@ -766,6 +772,12 @@ impl ChatComposer {
         self.sync_popups();
     }
 
+    pub(crate) fn set_vim_enabled(&mut self, enabled: bool) {
+        self.textarea.set_vim_enabled(enabled);
+        self.paste_burst.clear_after_explicit_paste();
+        self.footer_mode = reset_mode_after_activity(self.footer_mode);
+    }
+
     pub(crate) fn current_text_with_pending(&self) -> String {
         let mut text = self.textarea.text().to_string();
         for (placeholder, actual) in &self.pending_pastes {
@@ -2511,7 +2523,7 @@ impl ChatComposer {
             return (InputResult::None, true);
         }
         if key_event.code == KeyCode::Esc {
-            if self.is_empty() {
+            if self.is_empty() && !self.textarea.is_vim_insert() {
                 let next_mode = esc_hint_mode(self.footer_mode, self.is_task_running);
                 if next_mode != self.footer_mode {
                     self.footer_mode = next_mode;
@@ -2669,7 +2681,7 @@ impl ChatComposer {
         } = input
         {
             let has_ctrl_or_alt = has_ctrl_or_alt(modifiers);
-            if !has_ctrl_or_alt && !self.disable_paste_burst {
+            if !has_ctrl_or_alt && !self.disable_paste_burst && self.textarea.allows_paste_burst() {
                 // Non-ASCII characters (e.g., from IMEs) can arrive in quick bursts, so avoid
                 // holding the first char while still allowing burst detection for paste input.
                 if !ch.is_ascii() {
@@ -3678,6 +3690,13 @@ impl ChatComposer {
                         show_shortcuts_hint,
                         show_queue_hint,
                     );
+                    // Render vim mode indicator only in the default footer path so it does not
+                    // obscure flash/status/override content.
+                    if let Some(label) = self.textarea.vim_mode_label() {
+                        let vim_line = Line::from(format!("-- {label} --")).dim();
+                        let area = inset_footer_hint_area(hint_rect);
+                        vim_line.render(area, buf);
+                    }
                 }
 
                 if show_right && let Some(line) = &right_line {
@@ -3693,10 +3712,12 @@ impl ChatComposer {
                 .render_ref(remote_images_rect, buf);
         }
         if !textarea_rect.is_empty() {
-            let prompt = if self.input_enabled {
-                "›".bold()
-            } else {
+            let prompt = if !self.input_enabled {
                 "›".dim()
+            } else if self.textarea.vim_mode_label().is_some() && !self.textarea.is_vim_insert() {
+                "·".bold()
+            } else {
+                "›".bold()
             };
             buf.set_span(
                 textarea_rect.x - LIVE_PREFIX_COLS,

codex-rs/tui/src/bottom_pane/mod.rs

@@ -297,6 +297,11 @@ impl BottomPane {
         self.request_redraw();
     }
 
+    pub(crate) fn set_vim_enabled(&mut self, enabled: bool) {
+        self.composer.set_vim_enabled(enabled);
+        self.request_redraw();
+    }
+
     pub fn status_widget(&self) -> Option<&StatusIndicatorWidget> {
         self.status.as_ref()
     }