feat(coding-agent): add interactive-shell.ts extension example

Demonstrates running interactive commands (vim, git rebase, htop, etc.)
with full terminal access using user_bash event and ctx.ui.custom().

- Auto-detects interactive commands from built-in list
- !i prefix to force interactive mode
- Configurable via INTERACTIVE_COMMANDS/INTERACTIVE_EXCLUDE env vars

closes #532

packages/coding-agent/CHANGELOG.md

@@ -16,6 +16,7 @@
 - `setActiveTools()` in ExtensionAPI for dynamic tool management
 - Built-in renderers used automatically for tool overrides without custom `renderCall`/`renderResult`
 - `ssh.ts` example: remote tool execution via `--ssh user@host:/path`
+- `interactive-shell.ts` example: run interactive commands (vim, git rebase, htop) with full terminal access via `!i` prefix or auto-detection
 - Wayland clipboard support for `/copy` command using wl-copy with xclip/xsel fallback ([#570](https://github.com/badlogic/pi-mono/pull/570) by [@OgulcanCelik](https://github.com/OgulcanCelik))
 - **Experimental:** `ctx.ui.custom()` now accepts `{ overlay: true }` option for floating modal components that composite over existing content without clearing the screen ([#558](https://github.com/badlogic/pi-mono/pull/558) by [@nicobailon](https://github.com/nicobailon))
 - `AgentSession.skills` and `AgentSession.skillWarnings` properties to access loaded skills without rediscovery ([#577](https://github.com/badlogic/pi-mono/pull/577) by [@cv](https://github.com/cv))

packages/coding-agent/docs/extensions.md

@@ -543,7 +543,7 @@ pi.on("user_bash", (event, ctx) => {
 });
 ```
 
-**Examples:** [ssh.ts](../examples/extensions/ssh.ts)
+**Examples:** [ssh.ts](../examples/extensions/ssh.ts), [interactive-shell.ts](../examples/extensions/interactive-shell.ts)
 
 ## ExtensionContext
 

packages/coding-agent/examples/extensions/interactive-shell.ts

@@ -0,0 +1,196 @@
+/**
+ * Interactive Shell Commands Extension
+ *
+ * Enables running interactive commands (vim, git rebase -i, htop, etc.)
+ * with full terminal access. The TUI suspends while they run.
+ *
+ * Usage:
+ *   pi -e examples/extensions/interactive-shell.ts
+ *
+ *   !vim file.txt        # Auto-detected as interactive
+ *   !i any-command       # Force interactive mode with !i prefix
+ *   !git rebase -i HEAD~3
+ *   !htop
+ *
+ * Configuration via environment variables:
+ *   INTERACTIVE_COMMANDS - Additional commands (comma-separated)
+ *   INTERACTIVE_EXCLUDE  - Commands to exclude (comma-separated)
+ *
+ * Note: This only intercepts user `!` commands, not agent bash tool calls.
+ * If the agent runs an interactive command, it will fail (which is fine).
+ */
+
+import { spawnSync } from "node:child_process";
+import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
+
+// Default interactive commands - editors, pagers, git ops, TUIs
+const DEFAULT_INTERACTIVE_COMMANDS = [
+	// Editors
+	"vim",
+	"nvim",
+	"vi",
+	"nano",
+	"emacs",
+	"pico",
+	"micro",
+	"helix",
+	"hx",
+	"kak",
+	// Pagers
+	"less",
+	"more",
+	"most",
+	// Git interactive
+	"git commit",
+	"git rebase",
+	"git merge",
+	"git cherry-pick",
+	"git revert",
+	"git add -p",
+	"git add --patch",
+	"git add -i",
+	"git add --interactive",
+	"git stash -p",
+	"git stash --patch",
+	"git reset -p",
+	"git reset --patch",
+	"git checkout -p",
+	"git checkout --patch",
+	"git difftool",
+	"git mergetool",
+	// System monitors
+	"htop",
+	"top",
+	"btop",
+	"glances",
+	// File managers
+	"ranger",
+	"nnn",
+	"lf",
+	"mc",
+	"vifm",
+	// Git TUIs
+	"tig",
+	"lazygit",
+	"gitui",
+	// Fuzzy finders
+	"fzf",
+	"sk",
+	// Remote sessions
+	"ssh",
+	"telnet",
+	"mosh",
+	// Database clients
+	"psql",
+	"mysql",
+	"sqlite3",
+	"mongosh",
+	"redis-cli",
+	// Kubernetes/Docker
+	"kubectl edit",
+	"kubectl exec -it",
+	"docker exec -it",
+	"docker run -it",
+	// Other
+	"tmux",
+	"screen",
+	"ncdu",
+];
+
+function getInteractiveCommands(): string[] {
+	const additional =
+		process.env.INTERACTIVE_COMMANDS?.split(",")
+			.map((s) => s.trim())
+			.filter(Boolean) ?? [];
+	const excluded = new Set(process.env.INTERACTIVE_EXCLUDE?.split(",").map((s) => s.trim().toLowerCase()) ?? []);
+	return [...DEFAULT_INTERACTIVE_COMMANDS, ...additional].filter((cmd) => !excluded.has(cmd.toLowerCase()));
+}
+
+function isInteractiveCommand(command: string): boolean {
+	const trimmed = command.trim().toLowerCase();
+	const commands = getInteractiveCommands();
+
+	for (const cmd of commands) {
+		const cmdLower = cmd.toLowerCase();
+		// Match at start
+		if (trimmed === cmdLower || trimmed.startsWith(`${cmdLower} `) || trimmed.startsWith(`${cmdLower}\t`)) {
+			return true;
+		}
+		// Match after pipe: "cat file | less"
+		const pipeIdx = trimmed.lastIndexOf("|");
+		if (pipeIdx !== -1) {
+			const afterPipe = trimmed.slice(pipeIdx + 1).trim();
+			if (afterPipe === cmdLower || afterPipe.startsWith(`${cmdLower} `)) {
+				return true;
+			}
+		}
+	}
+	return false;
+}
+
+export default function (pi: ExtensionAPI) {
+	pi.on("user_bash", async (event, ctx) => {
+		let command = event.command;
+		let forceInteractive = false;
+
+		// Check for !i prefix (command comes without the leading !)
+		// The prefix parsing happens before this event, so we check if command starts with "i "
+		if (command.startsWith("i ") || command.startsWith("i\t")) {
+			forceInteractive = true;
+			command = command.slice(2).trim();
+		}
+
+		const shouldBeInteractive = forceInteractive || isInteractiveCommand(command);
+		if (!shouldBeInteractive) {
+			return; // Let normal handling proceed
+		}
+
+		// No UI available (print mode, RPC, etc.)
+		if (!ctx.hasUI) {
+			return {
+				result: { output: "(interactive commands require TUI)", exitCode: 1, cancelled: false, truncated: false },
+			};
+		}
+
+		// Use ctx.ui.custom() to get TUI access, then run the command
+		const exitCode = await ctx.ui.custom<number | null>((tui, _theme, _kb, done) => {
+			// Stop TUI to release terminal
+			tui.stop();
+
+			// Clear screen
+			process.stdout.write("\x1b[2J\x1b[H");
+
+			// Run command with full terminal access
+			const shell = process.env.SHELL || "/bin/sh";
+			const result = spawnSync(shell, ["-c", command], {
+				stdio: "inherit",
+				env: process.env,
+			});
+
+			// Restart TUI
+			tui.start();
+			tui.requestRender(true);
+
+			// Signal completion
+			done(result.status);
+
+			// Return empty component (immediately disposed since done() was called)
+			return { render: () => [], invalidate: () => {} };
+		});
+
+		// Return result to prevent default bash handling
+		const output =
+			exitCode === 0
+				? "(interactive command completed successfully)"
+				: `(interactive command exited with code ${exitCode})`;
+
+		return {
+			result: {
+				output,
+				exitCode: exitCode ?? 1,
+				cancelled: false,
+				truncated: false,
+			},
+		};
+	});
+}