feat: /Help command

codex-rs/tui/src/app.rs

@@ -9,6 +9,8 @@ use crate::onboarding::onboarding_screen::OnboardingScreenArgs;
 use crate::should_show_login_screen;
 use crate::slash_command::SlashCommand;
 use crate::tui;
+use clap::CommandFactory;
+use clap::Parser as ClapParser;
 use codex_core::config::Config;
 use codex_core::protocol::Event;
 use codex_core::protocol::EventMsg;
@@ -371,6 +373,24 @@ impl App<'_> {
                             widget.add_status_output();
                         }
                     }
+                    SlashCommand::Help => {
+                        if let AppState::Chat { widget } = &mut self.app_state {
+                            #[derive(ClapParser, Debug)]
+                            #[command(version)]
+                            struct HelpCli {
+                                #[clap(flatten)]
+                                config_overrides: codex_common::CliConfigOverrides,
+                                #[clap(flatten)]
+                                inner: crate::Cli,
+                            }
+
+                            let mut cmd = HelpCli::command();
+                            let mut buf: Vec<u8> = Vec::new();
+                            let _ = cmd.write_help(&mut buf);
+                            let help_text = String::from_utf8_lossy(&buf).to_string();
+                            widget.add_help_output(help_text);
+                        }
+                    }
                     SlashCommand::Prompts => {
                         if let AppState::Chat { widget } = &mut self.app_state {
                             widget.add_prompts_output();

codex-rs/tui/src/chatwidget.rs

@@ -618,6 +618,10 @@ impl ChatWidget<'_> {
         self.add_to_history(HistoryCell::new_prompts_output());
     }
 
+    pub(crate) fn add_help_output(&mut self, help_text: String) {
+        self.add_to_history(HistoryCell::new_help_output(help_text));
+    }
+
     /// Forward file-search results to the bottom pane.
     pub(crate) fn apply_file_search_result(&mut self, query: String, matches: Vec<FileMatch>) {
         self.bottom_pane.on_file_search_result(query, matches);

codex-rs/tui/src/history_cell.rs

@@ -129,6 +129,9 @@ pub(crate) enum HistoryCell {
         view: TextBlock,
     },
 
+    /// Output from the `/help` command.
+    HelpOutput { view: TextBlock },
+
     /// Error event from the backend.
     ErrorEvent {
         view: TextBlock,
@@ -194,6 +197,7 @@ impl HistoryCell {
             | HistoryCell::GitDiffOutput { view }
             | HistoryCell::StatusOutput { view }
             | HistoryCell::PromptsOutput { view }
+            | HistoryCell::HelpOutput { view }
             | HistoryCell::ErrorEvent { view }
             | HistoryCell::SessionInfo { view }
             | HistoryCell::CompletedMcpToolCall { view }
@@ -705,6 +709,18 @@ impl HistoryCell {
         }
     }
 
+    pub(crate) fn new_help_output(help_text: String) -> Self {
+        let mut lines: Vec<Line<'static>> = Vec::new();
+        lines.push(Line::from("/help".magenta()));
+        for l in help_text.lines() {
+            lines.push(Line::from(l.to_string()));
+        }
+        lines.push(Line::from(""));
+        HistoryCell::HelpOutput {
+            view: TextBlock::new(lines),
+        }
+    }
+
     pub(crate) fn new_error_event(message: String) -> Self {
         let lines: Vec<Line<'static>> =
             vec![vec!["🖐 ".red().bold(), message.into()].into(), "".into()];

codex-rs/tui/src/slash_command.rs

@@ -18,6 +18,7 @@ pub enum SlashCommand {
     Diff,
     Status,
     Prompts,
+    Help,
     Logout,
     Quit,
     #[cfg(debug_assertions)]
@@ -35,6 +36,7 @@ impl SlashCommand {
             SlashCommand::Diff => "show git diff (including untracked files)",
             SlashCommand::Status => "show current session configuration and token usage",
             SlashCommand::Prompts => "show example prompts",
+            SlashCommand::Help => "show command help",
             SlashCommand::Logout => "log out of Codex",
             #[cfg(debug_assertions)]
             SlashCommand::TestApproval => "test approval request",