fix(core): disable TUI on ai agents (#31480)

## Current Behavior

The TUI (Terminal User Interface) is enabled for all environments,
including AI agents like Claude Code, which can cause issues with
AI-driven development workflows.

## Expected Behavior

When an AI agent is detected through environment variables, the TUI
should be automatically disabled to prevent interference with AI-driven
interactions.

## Related Issue(s)

This change improves the developer experience when using AI agents by
automatically detecting their presence and adjusting the interface
accordingly.

---------

Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: FrozenPandaz <FrozenPandaz@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>

Author: 3 people

packages/nx/src/native/index.d.ts

@@ -252,6 +252,9 @@ export declare export declare function installNxConsole(): void
 
 export const IS_WASM: boolean
 
+/** Detects if the current process is being run by an AI agent */
+export declare export declare function isAiAgent(): boolean
+
 export declare export declare function logDebug(message: string): void
 
 /** Stripped version of the NxJson interface for use in rust */

packages/nx/src/native/native-bindings.js

@@ -392,6 +392,7 @@ module.exports.hashArray = nativeBinding.hashArray
 module.exports.hashFile = nativeBinding.hashFile
 module.exports.installNxConsole = nativeBinding.installNxConsole
 module.exports.IS_WASM = nativeBinding.IS_WASM
+module.exports.isAiAgent = nativeBinding.isAiAgent
 module.exports.logDebug = nativeBinding.logDebug
 module.exports.parseTaskStatus = nativeBinding.parseTaskStatus
 module.exports.remove = nativeBinding.remove

packages/nx/src/native/utils/ai.rs

@@ -0,0 +1,183 @@
+use std::env;
+use tracing::debug;
+
+/// Detects if the current process is being run by Claude Code
+fn is_claude_ai() -> bool {
+    match env::var("CLAUDECODE") {
+        Ok(_) => {
+            debug!("Claude AI detected via CLAUDECODE environment variable");
+            true
+        }
+        Err(_) => false,
+    }
+}
+
+/// Detects if the current process is being run by Repl.it
+fn is_replit_ai() -> bool {
+    match env::var("REPL_ID") {
+        Ok(_) => {
+            debug!("Repl.it AI detected via REPL_ID environment variable");
+            true
+        }
+        Err(_) => false,
+    }
+}
+
+/// Detects if the current process is being run by Cursor AI
+fn is_cursor_ai() -> bool {
+    let pager_matches = env::var("PAGER")
+        .map(|v| v == "head -n 10000 | cat")
+        .unwrap_or(false);
+    let has_cursor_trace_id = env::var("CURSOR_TRACE_ID").is_ok();
+    let has_composer_no_interaction = env::var("COMPOSER_NO_INTERACTION").is_ok();
+
+    let is_cursor = pager_matches && has_cursor_trace_id && has_composer_no_interaction;
+
+    if is_cursor {
+        debug!(
+            "Cursor AI detected via PAGER, CURSOR_TRACE_ID, and COMPOSER_NO_INTERACTION environment variables"
+        );
+    }
+
+    is_cursor
+}
+
+/// Detects if the current process is being run by an AI agent
+#[napi]
+pub fn is_ai_agent() -> bool {
+    let is_ai = is_claude_ai() || is_replit_ai() || is_cursor_ai();
+
+    if is_ai {
+        debug!("AI agent detected");
+    }
+
+    is_ai
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn clear_ai_env_vars() {
+        let ai_vars = [
+            "CLAUDECODE",
+            "REPL_ID",
+            "PAGER",
+            "CURSOR_TRACE_ID",
+            "COMPOSER_NO_INTERACTION",
+        ];
+        for var in &ai_vars {
+            unsafe {
+                std::env::remove_var(var);
+            }
+        }
+    }
+
+    #[test]
+    fn test_ai_agent_detection() {
+        // Save original environment state
+        let original_claudecode = env::var("CLAUDECODE").ok();
+        let original_repl_id = env::var("REPL_ID").ok();
+        let original_pager = env::var("PAGER").ok();
+        let original_cursor_trace_id = env::var("CURSOR_TRACE_ID").ok();
+        let original_composer_no_interaction = env::var("COMPOSER_NO_INTERACTION").ok();
+
+        // Start with clean environment
+        clear_ai_env_vars();
+
+        // Test no AI detection
+        assert!(
+            !is_claude_ai(),
+            "Should not detect Claude AI without CLAUDECODE"
+        );
+        assert!(
+            !is_replit_ai(),
+            "Should not detect Repl.it AI without REPL_ID"
+        );
+        assert!(
+            !is_cursor_ai(),
+            "Should not detect Cursor AI without all variables"
+        );
+        assert!(!is_ai_agent(), "Should not detect any AI agent");
+
+        // Test Claude AI detection
+        unsafe {
+            env::set_var("CLAUDECODE", "1");
+        }
+        assert!(is_claude_ai(), "Should detect Claude AI with CLAUDECODE");
+        assert!(is_ai_agent(), "Main function should detect Claude AI");
+        unsafe {
+            env::remove_var("CLAUDECODE");
+        }
+
+        // Test Repl.it AI detection
+        unsafe {
+            env::set_var("REPL_ID", "some-repl-id");
+        }
+        assert!(is_replit_ai(), "Should detect Repl.it AI with REPL_ID");
+        assert!(is_ai_agent(), "Main function should detect Repl.it AI");
+        unsafe {
+            env::remove_var("REPL_ID");
+        }
+
+        // Test Cursor AI detection with wrong PAGER
+        unsafe {
+            env::set_var("PAGER", "wrong-value");
+            env::set_var("CURSOR_TRACE_ID", "trace-123");
+            env::set_var("COMPOSER_NO_INTERACTION", "1");
+        }
+        assert!(
+            !is_cursor_ai(),
+            "Should not detect Cursor AI with wrong PAGER value"
+        );
+
+        // Test Cursor AI detection with correct PAGER
+        unsafe {
+            env::set_var("PAGER", "head -n 10000 | cat");
+        }
+        assert!(
+            is_cursor_ai(),
+            "Should detect Cursor AI with correct PAGER and all variables"
+        );
+        assert!(is_ai_agent(), "Main function should detect Cursor AI");
+        clear_ai_env_vars();
+
+        // Test multiple AI agents
+        unsafe {
+            env::set_var("CLAUDECODE", "1");
+            env::set_var("REPL_ID", "some-repl-id");
+        }
+        assert!(
+            is_ai_agent(),
+            "Should detect AI when multiple agents are present"
+        );
+
+        // Restore original environment
+        clear_ai_env_vars();
+        if let Some(val) = original_claudecode {
+            unsafe {
+                env::set_var("CLAUDECODE", val);
+            }
+        }
+        if let Some(val) = original_repl_id {
+            unsafe {
+                env::set_var("REPL_ID", val);
+            }
+        }
+        if let Some(val) = original_pager {
+            unsafe {
+                env::set_var("PAGER", val);
+            }
+        }
+        if let Some(val) = original_cursor_trace_id {
+            unsafe {
+                env::set_var("CURSOR_TRACE_ID", val);
+            }
+        }
+        if let Some(val) = original_composer_no_interaction {
+            unsafe {
+                env::set_var("COMPOSER_NO_INTERACTION", val);
+            }
+        }
+    }
+}

packages/nx/src/native/utils/mod.rs

@@ -10,6 +10,7 @@ pub use find_matching_projects::*;
 pub use get_mod_time::*;
 pub use normalize_trait::Normalize;
 
+pub mod ai;
 #[cfg_attr(not(target_arch = "wasm32"), path = "atomics/default.rs")]
 #[cfg_attr(target_arch = "wasm32", path = "atomics/wasm.rs")]
 pub mod atomics;

packages/nx/src/tasks-runner/is-tui-enabled.ts

@@ -1,5 +1,5 @@
 import type { NxJsonConfiguration } from '../config/nx-json';
-import { IS_WASM } from '../native';
+import { IS_WASM, isAiAgent } from '../native';
 import { NxArgs } from '../utils/command-line-utils';
 import { isCI } from '../utils/is-ci';
 import { logger } from '../utils/logger';
@@ -70,6 +70,8 @@ export function shouldUseTui(
   if (
     // Interactive TUI doesn't make sense on CI
     isCI() ||
+    // Interactive TUI doesn't make sense in an AI agent context
+    isAiAgent() ||
     // TODO(@JamesHenry): Remove this check once Windows issues are fixed.
     // Windows is not working well right now, temporarily disable it on Windows even if it has been specified as enabled
     isWindows ||