Fix Gemini Code's (GC) smarts.

- The tl;dr; is that GC couldn't see what the user was saying when tool call events happened in response. The rason why this was happening was because we were instantly invoking tools that the model told us to invoke and then instantly re-requesting. This resulted in the bug because the genai APIs can't update the chat history before a full response has been completed (doesn't know how to update if it's incomplete).
- To address the above issue I had to do quite the large refactor. The gist is that now turns truly drive everything on the server (vs. a server client split). This ensured that when we got tool invocations we could control when/how re-requesting would happen and then also ensure that history was updated. This change also meant that the server would act as an event publisher to enable the client to react to events rather than try and weave in complex logic between the events.
- A BIG change that this changeset incudes is the removal of all of the CLI tools in favor of the server tools.
- Removed some dead code as part of this
- **NOTE: Confirmations are still broken (they were broken prior to this); however, I've set them up to be able to work in the future, I'll dot hat in a follow up to be less breaking to others.**

Fixes https://b.corp.google.com/issues/412320087

1 files changed, 852 insertions, 107 deletions

diff --git a/packages/server/src/tools/terminal.ts b/packages/server/src/tools/terminal.ts
index 6366106c..eab170ab 100644
--- a/packages/server/src/tools/terminal.ts
+++ b/packages/server/src/tools/terminal.ts
@@ -4,18 +4,42 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { spawn, SpawnOptions } from 'child_process';
+import {
+  spawn,
+  SpawnOptions,
+  ChildProcessWithoutNullStreams,
+} from 'child_process';
 import path from 'path';
-import { BaseTool, ToolResult } from './tools.js';
-import { SchemaValidator } from '../utils/schemaValidator.js';
-import { getErrorMessage } from '../utils/errors.js';
+import os from 'os';
+import crypto from 'crypto';
+import { promises as fs } from 'fs';
+import {
+  SchemaValidator,
+  getErrorMessage,
+  isNodeError,
+  Config,
+} from '@gemini-code/server';
+import {
+  BaseTool,
+  ToolCallConfirmationDetails,
+  ToolConfirmationOutcome,
+  ToolExecuteConfirmationDetails,
+  ToolResult,
+} from './tools.js';
+import { BackgroundTerminalAnalyzer } from '../utils/BackgroundTerminalAnalyzer.js';
 
 export interface TerminalToolParams {
   command: string;
+  description?: string;
+  timeout?: number;
+  runInBackground?: boolean;
 }
 
 const MAX_OUTPUT_LENGTH = 10000;
-const DEFAULT_EXEC_TIMEOUT_MS = 5 * 60 * 1000;
+const DEFAULT_TIMEOUT_MS = 30 * 60 * 1000;
+const MAX_TIMEOUT_OVERRIDE_MS = 10 * 60 * 1000;
+const BACKGROUND_LAUNCH_TIMEOUT_MS = 15 * 1000;
+const BACKGROUND_POLL_TIMEOUT_MS = 30000;
 
 const BANNED_COMMAND_ROOTS = [
   'alias',
@@ -85,41 +109,197 @@ const BANNED_COMMAND_ROOTS = [
   'open',
 ];
 
-/**
- * Simplified implementation of the Terminal tool logic for single command execution.
- */
-export class TerminalLogic extends BaseTool<TerminalToolParams, ToolResult> {
-  static readonly Name = 'execute_bash_command';
+interface QueuedCommand {
+  params: TerminalToolParams;
+  resolve: (result: ToolResult) => void;
+  reject: (error: Error) => void;
+  confirmationDetails: ToolExecuteConfirmationDetails | false;
+}
+
+export class TerminalTool extends BaseTool<TerminalToolParams, ToolResult> {
+  static Name: string = 'execute_bash_command';
   private readonly rootDirectory: string;
+  private readonly outputLimit: number;
+  private bashProcess: ChildProcessWithoutNullStreams | null = null;
+  private currentCwd: string;
+  private isExecuting: boolean = false;
+  private commandQueue: QueuedCommand[] = [];
+  private currentCommandCleanup: (() => void) | null = null;
+  private shouldAlwaysExecuteCommands: Map<string, boolean> = new Map();
+  private shellReady: Promise<void>;
+  private resolveShellReady: (() => void) | undefined;
+  private rejectShellReady: ((reason?: unknown) => void) | undefined;
+  private readonly backgroundTerminalAnalyzer: BackgroundTerminalAnalyzer;
+  private readonly config: Config;
 
-  constructor(rootDirectory: string) {
-    super(
-      TerminalLogic.Name,
-      '', // Display name handled by CLI wrapper
-      '', // Description handled by CLI wrapper
-      {
-        type: 'object',
-        properties: {
-          command: {
-            description: `The exact bash command or sequence of commands (using ';' or '&&') to execute. Must adhere to usage guidelines. Example: 'npm install && npm run build'`,
-            type: 'string',
-          },
+  constructor(
+    rootDirectory: string,
+    config: Config,
+    outputLimit: number = MAX_OUTPUT_LENGTH,
+  ) {
+    const toolDisplayName = 'Terminal';
+    const toolDescription = `Executes one or more bash commands sequentially in a secure and persistent interactive shell session. Can run commands in the foreground (waiting for completion) or background (returning after launch, with subsequent status polling).
+
+Core Functionality:
+* Starts in project root: '${path.basename(rootDirectory)}'. Current Directory starts as: ${rootDirectory} (will update based on 'cd' commands).
+* Persistent State: Environment variables and the current working directory (\`pwd\`) persist between calls to this tool.
+* **Execution Modes:**
+    * **Foreground (default):** Waits for the command to complete. Captures stdout, stderr, and exit code. Output is truncated if it exceeds ${outputLimit} characters.
+    * **Background (\`runInBackground: true\`):** Appends \`&\` to the command and redirects its output to temporary files. Returns *after* the command is launched, providing the Process ID (PID) and launch status. Subsequently, the tool **polls** for the background process status for up to ${BACKGROUND_POLL_TIMEOUT_MS / 1000} seconds. Once the process finishes or polling times out, the tool reads the captured stdout/stderr from the temporary files, runs an internal LLM analysis on the output, cleans up the files, and returns the final status, captured output, and analysis.
+* Timeout: Optional timeout per 'execute' call (default: ${DEFAULT_TIMEOUT_MS / 60000} min, max override: ${MAX_TIMEOUT_OVERRIDE_MS / 60000} min for foreground). Background *launch* has a fixed shorter timeout (${BACKGROUND_LAUNCH_TIMEOUT_MS / 1000}s) for the launch attempt itself. Background *polling* has its own timeout (${BACKGROUND_POLL_TIMEOUT_MS / 1000}s). Timeout attempts SIGINT for foreground commands.
+
+Usage Guidance & Restrictions:
+
+1.  **Directory/File Verification (IMPORTANT):**
+    * BEFORE executing commands that create files or directories (e.g., \`mkdir foo/bar\`, \`touch new/file.txt\`, \`git clone ...\`), use the dedicated File System tool (e.g., 'list_directory') to verify the target parent directory exists and is the correct location.
+    * Example: Before running \`mkdir foo/bar\`, first use the File System tool to check that \`foo\` exists in the current directory (\`${rootDirectory}\` initially, check current CWD if it changed).
+
+2.  **Use Specialized Tools (CRITICAL):**
+    * Do NOT use this tool for filesystem searching (\`find\`, \`grep\`). Use the dedicated Search tool instead.
+    * Do NOT use this tool for reading files (\`cat\`, \`head\`, \`tail\`, \`less\`, \`more\`). Use the dedicated File Reader tool instead.
+    * Do NOT use this tool for listing files (\`ls\`). Use the dedicated File System tool ('list_directory') instead. Relying on this tool's output for directory structure is unreliable due to potential truncation and lack of structured data.
+
+3.  **Security & Banned Commands:**
+    * Certain commands are banned for security (e.g., network: ${BANNED_COMMAND_ROOTS.filter((c) => ['curl', 'wget', 'ssh'].includes(c)).join(', ')}; session: ${BANNED_COMMAND_ROOTS.filter((c) => ['exit', 'export', 'kill'].includes(c)).join(', ')}; etc.). The full list is extensive.
+    * If you attempt a banned command, this tool will return an error explaining the restriction. You MUST relay this error clearly to the user.
+
+4.  **Command Execution Notes:**
+    * Chain multiple commands using shell operators like ';' or '&&'. Do NOT use newlines within the 'command' parameter string itself (newlines are fine inside quoted arguments).
+    * The shell's current working directory is tracked internally. While \`cd\` is permitted if the user explicitly asks or it's necessary for a workflow, **strongly prefer** using absolute paths or paths relative to the *known* current working directory to avoid errors. Check the '(Executed in: ...)' part of the previous command's output for the CWD.
+        * Good example (if CWD is /workspace/project): \`pytest tests/unit\` or \`ls /workspace/project/data\`
+        * Less preferred: \`cd tests && pytest unit\` (only use if necessary or requested)
+
+5.  **Background Tasks (\`runInBackground: true\`):**
+    * Use this for commands that are intended to run continuously (e.g., \`node server.js\`, \`npm start\`).
+    * The tool initially returns success if the process *launches* successfully, along with its PID.
+    * **Polling & Final Result:** The tool then monitors the process. The *final* result (delivered after polling completes or times out) will include:
+        * The final status (completed or timed out).
+        * The complete stdout and stderr captured in temporary files (truncated if necessary).
+        * An LLM-generated analysis/summary of the output.
+    * The initial exit code (usually 0) signifies successful *launching*; the final status indicates completion or timeout after polling.
+
+Use this tool for running build steps (\`npm install\`, \`make\`), linters (\`eslint .\`), test runners (\`pytest\`, \`jest\`), code formatters (\`prettier --write .\`), package managers (\`pip install\`), version control operations (\`git status\`, \`git diff\`), starting background servers/services (\`node server.js --runInBackground true\`), or other safe, standard command-line operations within the project workspace.`;
+    const toolParameterSchema = {
+      type: 'object',
+      properties: {
+        command: {
+          description: `The exact bash command or sequence of commands (using ';' or '&&') to execute. Must adhere to usage guidelines. Example: 'npm install && npm run build'`,
+          type: 'string',
+        },
+        description: {
+          description: `Optional: A brief, user-centric explanation of what the command does and why it's being run. Used for logging and confirmation prompts. Example: 'Install project dependencies'`,
+          type: 'string',
+        },
+        timeout: {
+          description: `Optional execution time limit in milliseconds for FOREGROUND commands. Max ${MAX_TIMEOUT_OVERRIDE_MS}ms (${MAX_TIMEOUT_OVERRIDE_MS / 60000} min). Defaults to ${DEFAULT_TIMEOUT_MS}ms (${DEFAULT_TIMEOUT_MS / 60000} min) if not specified or invalid. Ignored if 'runInBackground' is true.`,
+          type: 'number',
+        },
+        runInBackground: {
+          description: `If true, execute the command in the background using '&'. Defaults to false. Use for servers or long tasks.`,
+          type: 'boolean',
         },
-        required: ['command'],
       },
+      required: ['command'],
+    };
+    super(
+      TerminalTool.Name,
+      toolDisplayName,
+      toolDescription,
+      toolParameterSchema,
     );
+    this.config = config;
     this.rootDirectory = path.resolve(rootDirectory);
+    this.currentCwd = this.rootDirectory;
+    this.outputLimit = outputLimit;
+    this.shellReady = new Promise((resolve, reject) => {
+      this.resolveShellReady = resolve;
+      this.rejectShellReady = reject;
+    });
+    this.backgroundTerminalAnalyzer = new BackgroundTerminalAnalyzer(config);
+    this.initializeShell();
+  }
+
+  private initializeShell() {
+    if (this.bashProcess) {
+      try {
+        this.bashProcess.kill();
+      } catch {
+        /* Ignore */
+      }
+    }
+    const spawnOptions: SpawnOptions = {
+      cwd: this.rootDirectory,
+      shell: true,
+      env: { ...process.env },
+      stdio: ['pipe', 'pipe', 'pipe'],
+    };
+    try {
+      const bashPath = os.platform() === 'win32' ? 'bash.exe' : 'bash';
+      this.bashProcess = spawn(
+        bashPath,
+        ['-s'],
+        spawnOptions,
+      ) as ChildProcessWithoutNullStreams;
+      this.currentCwd = this.rootDirectory;
+      this.bashProcess.on('error', (err) => {
+        console.error('Persistent Bash Error:', err);
+        this.rejectShellReady?.(err);
+        this.bashProcess = null;
+        this.isExecuting = false;
+        this.clearQueue(
+          new Error(`Persistent bash process failed to start: ${err.message}`),
+        );
+      });
+      this.bashProcess.on('close', (code, signal) => {
+        this.bashProcess = null;
+        this.isExecuting = false;
+        this.rejectShellReady?.(
+          new Error(
+            `Persistent bash process exited (code: ${code}, signal: ${signal})`,
+          ),
+        );
+        this.shellReady = new Promise((resolve, reject) => {
+          this.resolveShellReady = resolve;
+          this.rejectShellReady = reject;
+        });
+        this.clearQueue(
+          new Error(
+            `Persistent bash process exited unexpectedly (code: ${code}, signal: ${signal}). State is lost. Queued commands cancelled.`,
+          ),
+        );
+        if (signal !== 'SIGINT') {
+          setTimeout(() => this.initializeShell(), 1000);
+        }
+      });
+      setTimeout(() => {
+        if (this.bashProcess && !this.bashProcess.killed) {
+          this.resolveShellReady?.();
+        } else if (!this.bashProcess) {
+          // Error likely handled
+        } else {
+          this.rejectShellReady?.(
+            new Error('Shell killed during initialization'),
+          );
+        }
+      }, 1000);
+    } catch (error: unknown) {
+      console.error('Failed to spawn persistent bash:', error);
+      this.rejectShellReady?.(error);
+      this.bashProcess = null;
+      this.clearQueue(
+        new Error(`Failed to spawn persistent bash: ${getErrorMessage(error)}`),
+      );
+    }
   }
 
-  validateParams(params: TerminalToolParams): string | null {
+  validateToolParams(params: TerminalToolParams): string | null {
     if (
-      this.schema.parameters &&
       !SchemaValidator.validate(
-        this.schema.parameters as Record<string, unknown>,
+        this.parameterSchema as Record<string, unknown>,
         params,
       )
     ) {
-      return "Parameters failed schema validation (expecting only 'command').";
+      return `Parameters failed schema validation.`;
     }
     const commandOriginal = params.command.trim();
     if (!commandOriginal) {
@@ -137,120 +317,685 @@ export class TerminalLogic extends BaseTool<TerminalToolParams, ToolResult> {
         return `Command contains a banned keyword: '${cleanPart}'. Banned list includes network tools, session control, etc.`;
       }
     }
+    if (
+      params.timeout !== undefined &&
+      (typeof params.timeout !== 'number' || params.timeout <= 0)
+    ) {
+      return 'Timeout must be a positive number of milliseconds.';
+    }
     return null;
   }
 
   getDescription(params: TerminalToolParams): string {
-    return params.command;
+    return params.description || params.command;
   }
 
-  async execute(
+  async shouldConfirmExecute(
     params: TerminalToolParams,
-    executionCwd?: string,
-    timeout: number = DEFAULT_EXEC_TIMEOUT_MS,
-  ): Promise<ToolResult> {
-    const validationError = this.validateParams(params);
+  ): Promise<ToolCallConfirmationDetails | false> {
+    const rootCommand =
+      params.command
+        .trim()
+        .split(/[\s;&&|]+/)[0]
+        ?.split(/[/\\]/)
+        .pop() || 'unknown';
+    if (this.shouldAlwaysExecuteCommands.get(rootCommand)) {
+      return false;
+    }
+    const description = this.getDescription(params);
+    const confirmationDetails: ToolExecuteConfirmationDetails = {
+      title: 'Confirm Shell Command',
+      command: params.command,
+      rootCommand,
+      description: `Execute in '${this.currentCwd}':\n${description}`,
+      onConfirm: async (outcome: ToolConfirmationOutcome) => {
+        if (outcome === ToolConfirmationOutcome.ProceedAlways) {
+          this.shouldAlwaysExecuteCommands.set(rootCommand, true);
+        }
+      },
+    };
+    return confirmationDetails;
+  }
+
+  async execute(params: TerminalToolParams): Promise<ToolResult> {
+    const validationError = this.validateToolParams(params);
     if (validationError) {
       return {
         llmContent: `Command rejected: ${params.command}\nReason: ${validationError}`,
         returnDisplay: `Error: ${validationError}`,
       };
     }
-
-    const cwd = executionCwd ? path.resolve(executionCwd) : this.rootDirectory;
-    if (!cwd.startsWith(this.rootDirectory) && cwd !== this.rootDirectory) {
-      const message = `Execution CWD validation failed: Attempted path "${cwd}" resolves outside the allowed root directory "${this.rootDirectory}".`;
-      return {
-        llmContent: `Command rejected: ${params.command}\nReason: ${message}`,
-        returnDisplay: `Error: ${message}`,
-      };
-    }
-
     return new Promise((resolve) => {
-      const spawnOptions: SpawnOptions = {
-        cwd,
-        shell: true,
-        env: { ...process.env },
-        stdio: 'pipe',
-        windowsHide: true,
-        timeout: timeout,
+      const queuedItem: QueuedCommand = {
+        params,
+        resolve,
+        reject: (error) =>
+          resolve({
+            llmContent: `Internal tool error for command: ${params.command}\nError: ${error.message}`,
+            returnDisplay: `Internal Tool Error: ${error.message}`,
+          }),
+        confirmationDetails: false,
       };
-      let stdout = '';
-      let stderr = '';
-      let processError: Error | null = null;
-      let timedOut = false;
+      this.commandQueue.push(queuedItem);
+      setImmediate(() => this.triggerQueueProcessing());
+    });
+  }
 
-      try {
-        const child = spawn(params.command, spawnOptions);
-        child.stdout!.on('data', (data) => {
-          stdout += data.toString();
-          if (stdout.length > MAX_OUTPUT_LENGTH) {
-            stdout = this.truncateOutput(stdout);
-            child.stdout!.pause();
+  private async triggerQueueProcessing(): Promise<void> {
+    if (this.isExecuting || this.commandQueue.length === 0) {
+      return;
+    }
+    this.isExecuting = true;
+    const { params, resolve, reject } = this.commandQueue.shift()!;
+    try {
+      await this.shellReady;
+      if (!this.bashProcess || this.bashProcess.killed) {
+        throw new Error(
+          'Persistent bash process is not available or was killed.',
+        );
+      }
+      const result = await this.executeCommandInShell(params);
+      resolve(result);
+    } catch (error: unknown) {
+      console.error(`Error executing command "${params.command}":`, error);
+      if (error instanceof Error) {
+        reject(error);
+      } else {
+        reject(new Error('Unknown error occurred: ' + JSON.stringify(error)));
+      }
+    } finally {
+      this.isExecuting = false;
+      setImmediate(() => this.triggerQueueProcessing());
+    }
+  }
+
+  private executeCommandInShell(
+    params: TerminalToolParams,
+  ): Promise<ToolResult> {
+    let tempStdoutPath: string | null = null;
+    let tempStderrPath: string | null = null;
+    let originalResolve: (value: ToolResult | PromiseLike<ToolResult>) => void;
+    let originalReject: (reason?: unknown) => void;
+    const promise = new Promise<ToolResult>((resolve, reject) => {
+      originalResolve = resolve;
+      originalReject = reject;
+      if (!this.bashProcess) {
+        return reject(
+          new Error('Bash process is not running. Cannot execute command.'),
+        );
+      }
+      const isBackgroundTask = params.runInBackground ?? false;
+      const commandUUID = crypto.randomUUID();
+      const startDelimiter = `::START_CMD_${commandUUID}::`;
+      const endDelimiter = `::END_CMD_${commandUUID}::`;
+      const exitCodeDelimiter = `::EXIT_CODE_${commandUUID}::`;
+      const pidDelimiter = `::PID_${commandUUID}::`;
+      if (isBackgroundTask) {
+        try {
+          const tempDir = os.tmpdir();
+          tempStdoutPath = path.join(tempDir, `term_out_${commandUUID}.log`);
+          tempStderrPath = path.join(tempDir, `term_err_${commandUUID}.log`);
+        } catch (err: unknown) {
+          return reject(
+            new Error(
+              `Failed to determine temporary directory: ${getErrorMessage(err)}`,
+            ),
+          );
+        }
+      }
+      let stdoutBuffer = '';
+      let stderrBuffer = '';
+      let commandOutputStarted = false;
+      let exitCode: number | null = null;
+      let backgroundPid: number | null = null;
+      let receivedEndDelimiter = false;
+      const effectiveTimeout = isBackgroundTask
+        ? BACKGROUND_LAUNCH_TIMEOUT_MS
+        : Math.min(
+            params.timeout ?? DEFAULT_TIMEOUT_MS,
+            MAX_TIMEOUT_OVERRIDE_MS,
+          );
+      let onStdoutData: ((data: Buffer) => void) | null = null;
+      let onStderrData: ((data: Buffer) => void) | null = null;
+      let launchTimeoutId: NodeJS.Timeout | null = null;
+      launchTimeoutId = setTimeout(() => {
+        const timeoutMessage = isBackgroundTask
+          ? `Background command launch timed out after ${effectiveTimeout}ms.`
+          : `Command timed out after ${effectiveTimeout}ms.`;
+        if (!isBackgroundTask && this.bashProcess && !this.bashProcess.killed) {
+          try {
+            this.bashProcess.stdin.write('\x03');
+          } catch (e: unknown) {
+            console.error('Error writing SIGINT on timeout:', e);
           }
+        }
+        const listenersToClean = { onStdoutData, onStderrData };
+        cleanupListeners(listenersToClean);
+        if (isBackgroundTask && tempStdoutPath && tempStderrPath) {
+          this.cleanupTempFiles(tempStdoutPath, tempStderrPath).catch((err) => {
+            console.warn(
+              `Error cleaning up temp files on timeout: ${err.message}`,
+            );
+          });
+        }
+        originalResolve({
+          llmContent: `Command execution failed: ${timeoutMessage}\nCommand: ${params.command}\nExecuted in: ${this.currentCwd}\n${isBackgroundTask ? 'Mode: Background Launch' : `Mode: Foreground\nTimeout Limit: ${effectiveTimeout}ms`}\nPartial Stdout (Launch):\n${this.truncateOutput(stdoutBuffer)}\nPartial Stderr (Launch):\n${this.truncateOutput(stderrBuffer)}\nNote: ${isBackgroundTask ? 'Launch failed or took too long.' : 'Attempted interrupt (SIGINT). Shell state might be unpredictable if command ignored interrupt.'}`,
+          returnDisplay: `Timeout: ${timeoutMessage}`,
         });
-        child.stderr!.on('data', (data) => {
-          stderr += data.toString();
-          if (stderr.length > MAX_OUTPUT_LENGTH) {
-            stderr = this.truncateOutput(stderr);
-            child.stderr!.pause();
+      }, effectiveTimeout);
+      const processDataChunk = (chunk: string, isStderr: boolean): boolean => {
+        let dataToProcess = chunk;
+        if (!commandOutputStarted) {
+          const startIndex = dataToProcess.indexOf(startDelimiter);
+          if (startIndex !== -1) {
+            commandOutputStarted = true;
+            dataToProcess = dataToProcess.substring(
+              startIndex + startDelimiter.length,
+            );
+          } else {
+            return false;
           }
-        });
-        child.on('error', (err) => {
-          processError = err;
+        }
+        const pidIndex = dataToProcess.indexOf(pidDelimiter);
+        if (pidIndex !== -1) {
+          const pidMatch = dataToProcess
+            .substring(pidIndex + pidDelimiter.length)
+            .match(/^(\d+)/);
+          if (pidMatch?.[1]) {
+            backgroundPid = parseInt(pidMatch[1], 10);
+            const pidEndIndex =
+              pidIndex + pidDelimiter.length + pidMatch[1].length;
+            const beforePid = dataToProcess.substring(0, pidIndex);
+            if (isStderr) stderrBuffer += beforePid;
+            else stdoutBuffer += beforePid;
+            dataToProcess = dataToProcess.substring(pidEndIndex);
+          } else {
+            const beforePid = dataToProcess.substring(0, pidIndex);
+            if (isStderr) stderrBuffer += beforePid;
+            else stdoutBuffer += beforePid;
+            dataToProcess = dataToProcess.substring(
+              pidIndex + pidDelimiter.length,
+            );
+          }
+        }
+        const exitCodeIndex = dataToProcess.indexOf(exitCodeDelimiter);
+        if (exitCodeIndex !== -1) {
+          const exitCodeMatch = dataToProcess
+            .substring(exitCodeIndex + exitCodeDelimiter.length)
+            .match(/^(\d+)/);
+          if (exitCodeMatch?.[1]) {
+            exitCode = parseInt(exitCodeMatch[1], 10);
+            const beforeExitCode = dataToProcess.substring(0, exitCodeIndex);
+            if (isStderr) stderrBuffer += beforeExitCode;
+            else stdoutBuffer += beforeExitCode;
+            dataToProcess = dataToProcess.substring(
+              exitCodeIndex +
+                exitCodeDelimiter.length +
+                exitCodeMatch[1].length,
+            );
+          } else {
+            const beforeExitCode = dataToProcess.substring(0, exitCodeIndex);
+            if (isStderr) stderrBuffer += beforeExitCode;
+            else stdoutBuffer += beforeExitCode;
+            dataToProcess = dataToProcess.substring(
+              exitCodeIndex + exitCodeDelimiter.length,
+            );
+          }
+        }
+        const endDelimiterIndex = dataToProcess.indexOf(endDelimiter);
+        if (endDelimiterIndex !== -1) {
+          receivedEndDelimiter = true;
+          const beforeEndDelimiter = dataToProcess.substring(
+            0,
+            endDelimiterIndex,
+          );
+          if (isStderr) stderrBuffer += beforeEndDelimiter;
+          else stdoutBuffer += beforeEndDelimiter;
+          const afterEndDelimiter = dataToProcess.substring(
+            endDelimiterIndex + endDelimiter.length,
+          );
+          const exitCodeEchoMatch = afterEndDelimiter.match(/^(\d+)/);
+          dataToProcess = exitCodeEchoMatch
+            ? afterEndDelimiter.substring(exitCodeEchoMatch[1].length)
+            : afterEndDelimiter;
+        }
+        if (dataToProcess.length > 0) {
+          if (isStderr) stderrBuffer += dataToProcess;
+          else stdoutBuffer += dataToProcess;
+        }
+        if (receivedEndDelimiter && exitCode !== null) {
+          setImmediate(cleanupAndResolve);
+          return true;
+        }
+        return false;
+      };
+      onStdoutData = (data: Buffer) => processDataChunk(data.toString(), false);
+      onStderrData = (data: Buffer) => processDataChunk(data.toString(), true);
+      const cleanupListeners = (listeners?: {
+        onStdoutData: ((data: Buffer) => void) | null;
+        onStderrData: ((data: Buffer) => void) | null;
+      }) => {
+        if (launchTimeoutId) clearTimeout(launchTimeoutId);
+        launchTimeoutId = null;
+        const stdoutListener = listeners?.onStdoutData ?? onStdoutData;
+        const stderrListener = listeners?.onStderrData ?? onStderrData;
+        if (this.bashProcess && !this.bashProcess.killed) {
+          if (stdoutListener)
+            this.bashProcess.stdout.removeListener('data', stdoutListener);
+          if (stderrListener)
+            this.bashProcess.stderr.removeListener('data', stderrListener);
+        }
+        if (this.currentCommandCleanup === cleanupListeners) {
+          this.currentCommandCleanup = null;
+        }
+        onStdoutData = null;
+        onStderrData = null;
+      };
+      this.currentCommandCleanup = cleanupListeners;
+      const cleanupAndResolve = async () => {
+        if (
+          !this.currentCommandCleanup ||
+          this.currentCommandCleanup !== cleanupListeners
+        ) {
+          if (isBackgroundTask && tempStdoutPath && tempStderrPath) {
+            this.cleanupTempFiles(tempStdoutPath, tempStderrPath).catch(
+              (err) => {
+                console.warn(
+                  `Error cleaning up temp files for superseded command: ${err.message}`,
+                );
+              },
+            );
+          }
+          return;
+        }
+        const launchStdout = this.truncateOutput(stdoutBuffer);
+        const launchStderr = this.truncateOutput(stderrBuffer);
+        const listenersToClean = { onStdoutData, onStderrData };
+        cleanupListeners(listenersToClean);
+        if (exitCode === null) {
           console.error(
-            `TerminalLogic spawn error for "${params.command}":`,
-            err,
+            `CRITICAL: Command "${params.command}" (background: ${isBackgroundTask}) finished delimiter processing but exitCode is null.`,
           );
-        });
-        child.on('close', (code, signal) => {
-          const exitCode = code ?? (signal ? -1 : -2);
-          if (signal === 'SIGTERM' || signal === 'SIGKILL') {
-            if (child.killed && timeout > 0) timedOut = true;
+          const errorMode = isBackgroundTask
+            ? 'Background Launch'
+            : 'Foreground';
+          if (isBackgroundTask && tempStdoutPath && tempStderrPath) {
+            await this.cleanupTempFiles(tempStdoutPath, tempStderrPath);
+          }
+          originalResolve({
+            llmContent: `Command: ${params.command}\nExecuted in: ${this.currentCwd}\nMode: ${errorMode}\nExit Code: -2 (Internal Error: Exit code not captured)\nStdout (during setup):\n${launchStdout}\nStderr (during setup):\n${launchStderr}`,
+            returnDisplay:
+              `Internal Error: Failed to capture command exit code.\n${launchStdout}\nStderr: ${launchStderr}`.trim(),
+          });
+          return;
+        }
+        let cwdUpdateError = '';
+        if (!isBackgroundTask) {
+          const mightChangeCwd = params.command.trim().startsWith('cd ');
+          if (exitCode === 0 || mightChangeCwd) {
+            try {
+              const latestCwd = await this.getCurrentShellCwd();
+              if (this.currentCwd !== latestCwd) {
+                this.currentCwd = latestCwd;
+              }
+            } catch (e: unknown) {
+              if (exitCode === 0) {
+                cwdUpdateError = `\nWarning: Failed to verify/update current working directory after command: ${getErrorMessage(e)}`;
+                console.error(
+                  'Failed to update CWD after successful command:',
+                  e,
+                );
+              }
+            }
           }
-          const finalStdout = this.truncateOutput(stdout);
-          const finalStderr = this.truncateOutput(stderr);
-          let llmContent = `Command: ${params.command}\nExecuted in: ${cwd}\nExit Code: ${exitCode}\n`;
-          if (timedOut) llmContent += `Status: Timed Out after ${timeout}ms\n`;
-          if (processError)
-            llmContent += `Process Error: ${processError.message}\n`;
-          llmContent += `Stdout:\n${finalStdout}\nStderr:\n${finalStderr}`;
-          let displayOutput = finalStderr.trim() || finalStdout.trim();
-          if (timedOut)
-            displayOutput = `Timeout: ${displayOutput || 'No output before timeout'}`;
-          else if (exitCode !== 0 && !displayOutput)
-            displayOutput = `Failed (Exit Code: ${exitCode})`;
-          else if (exitCode === 0 && !displayOutput)
+        }
+        if (isBackgroundTask) {
+          const launchSuccess = exitCode === 0;
+          const pidString =
+            backgroundPid !== null ? backgroundPid.toString() : 'Not Captured';
+          if (
+            launchSuccess &&
+            backgroundPid !== null &&
+            tempStdoutPath &&
+            tempStderrPath
+          ) {
+            this.inspectBackgroundProcess(
+              backgroundPid,
+              params.command,
+              this.currentCwd,
+              launchStdout,
+              launchStderr,
+              tempStdoutPath,
+              tempStderrPath,
+              originalResolve,
+            );
+          } else {
+            const reason =
+              backgroundPid === null
+                ? 'PID not captured'
+                : `Launch failed (Exit Code: ${exitCode})`;
+            const displayMessage = `Failed to launch process in background (${reason})`;
+            console.error(
+              `Background launch failed for command: ${params.command}. Reason: ${reason}`,
+            );
+            if (tempStdoutPath && tempStderrPath) {
+              await this.cleanupTempFiles(tempStdoutPath, tempStderrPath);
+            }
+            originalResolve({
+              llmContent: `Background Command Launch Failed: ${params.command}\nExecuted in: ${this.currentCwd}\nReason: ${reason}\nPID: ${pidString}\nExit Code (Launch): ${exitCode}\nStdout (During Launch):\n${launchStdout}\nStderr (During Launch):\n${launchStderr}`,
+              returnDisplay: displayMessage,
+            });
+          }
+        } else {
+          let displayOutput = '';
+          const stdoutTrimmed = launchStdout.trim();
+          const stderrTrimmed = launchStderr.trim();
+          if (stderrTrimmed) {
+            displayOutput = stderrTrimmed;
+          } else if (stdoutTrimmed) {
+            displayOutput = stdoutTrimmed;
+          }
+          if (exitCode !== 0 && !displayOutput) {
+            displayOutput = `Failed with exit code: ${exitCode}`;
+          } else if (exitCode === 0 && !displayOutput) {
             displayOutput = `Success (no output)`;
-          resolve({
-            llmContent,
+          }
+          originalResolve({
+            llmContent: `Command: ${params.command}\nExecuted in: ${this.currentCwd}\nExit Code: ${exitCode}\nStdout:\n${launchStdout}\nStderr:\n${launchStderr}${cwdUpdateError}`,
             returnDisplay: displayOutput.trim() || `Exit Code: ${exitCode}`,
           });
-        });
-      } catch (spawnError: unknown) {
-        const errMsg = getErrorMessage(spawnError);
+        }
+      };
+      if (!this.bashProcess || this.bashProcess.killed) {
         console.error(
-          `TerminalLogic failed to spawn "${params.command}":`,
-          spawnError,
+          'Bash process lost or killed before listeners could be attached.',
+        );
+        if (isBackgroundTask && tempStdoutPath && tempStderrPath) {
+          this.cleanupTempFiles(tempStdoutPath, tempStderrPath).catch((err) => {
+            console.warn(
+              `Error cleaning up temp files on attach failure: ${err.message}`,
+            );
+          });
+        }
+        return originalReject(
+          new Error(
+            'Bash process lost or killed before listeners could be attached.',
+          ),
+        );
+      }
+      if (onStdoutData) this.bashProcess.stdout.on('data', onStdoutData);
+      if (onStderrData) this.bashProcess.stderr.on('data', onStderrData);
+      let commandToWrite: string;
+      if (isBackgroundTask && tempStdoutPath && tempStderrPath) {
+        commandToWrite = `echo "${startDelimiter}"; { { ${params.command} > "${tempStdoutPath}" 2> "${tempStderrPath}"; } & } 2>/dev/null; __LAST_PID=$!; echo "${pidDelimiter}$__LAST_PID" >&2; echo "${exitCodeDelimiter}$?" >&2; echo "${endDelimiter}$?" >&1\n`;
+      } else if (!isBackgroundTask) {
+        commandToWrite = `echo "${startDelimiter}"; ${params.command}; __EXIT_CODE=$?; echo "${exitCodeDelimiter}$__EXIT_CODE" >&2; echo "${endDelimiter}$__EXIT_CODE" >&1\n`;
+      } else {
+        return originalReject(
+          new Error(
+            'Internal setup error: Missing temporary file paths for background execution.',
+          ),
+        );
+      }
+      try {
+        if (this.bashProcess?.stdin?.writable) {
+          this.bashProcess.stdin.write(commandToWrite, (err) => {
+            if (err) {
+              console.error(
+                `Error writing command "${params.command}" to bash stdin (callback):`,
+                err,
+              );
+              const listenersToClean = { onStdoutData, onStderrData };
+              cleanupListeners(listenersToClean);
+              if (isBackgroundTask && tempStdoutPath && tempStderrPath) {
+                this.cleanupTempFiles(tempStdoutPath, tempStderrPath).catch(
+                  (e) => console.warn(`Cleanup failed: ${e.message}`),
+                );
+              }
+              originalReject(
+                new Error(
+                  `Shell stdin write error: ${err.message}. Command likely did not execute.`,
+                ),
+              );
+            }
+          });
+        } else {
+          throw new Error(
+            'Shell stdin is not writable or process closed when attempting to write command.',
+          );
+        }
+      } catch (e: unknown) {
+        console.error(
+          `Error writing command "${params.command}" to bash stdin (sync):`,
+          e,
+        );
+        const listenersToClean = { onStdoutData, onStderrData };
+        cleanupListeners(listenersToClean);
+        if (isBackgroundTask && tempStdoutPath && tempStderrPath) {
+          this.cleanupTempFiles(tempStdoutPath, tempStderrPath).catch((err) =>
+            console.warn(`Cleanup failed: ${err.message}`),
+          );
+        }
+        originalReject(
+          new Error(
+            `Shell stdin write exception: ${getErrorMessage(e)}. Command likely did not execute.`,
+          ),
         );
-        resolve({
-          llmContent: `Failed to start command: ${params.command}\nError: ${errMsg}`,
-          returnDisplay: `Error spawning command: ${errMsg}`,
-        });
       }
     });
+    return promise;
   }
 
-  private truncateOutput(
-    output: string,
-    limit: number = MAX_OUTPUT_LENGTH,
-  ): string {
-    if (output.length > limit) {
+  private async inspectBackgroundProcess(
+    pid: number,
+    command: string,
+    cwd: string,
+    initialStdout: string,
+    initialStderr: string,
+    tempStdoutPath: string,
+    tempStderrPath: string,
+    resolve: (value: ToolResult | PromiseLike<ToolResult>) => void,
+  ): Promise<void> {
+    let finalStdout = '';
+    let finalStderr = '';
+    let llmAnalysis = '';
+    let fileReadError = '';
+    try {
+      const { status, summary } = await this.backgroundTerminalAnalyzer.analyze(
+        pid,
+        tempStdoutPath,
+        tempStderrPath,
+        command,
+      );
+      if (status === 'Unknown') llmAnalysis = `LLM analysis failed: ${summary}`;
+      else llmAnalysis = summary;
+    } catch (llmerror: unknown) {
+      console.error(
+        `LLM analysis failed for PID ${pid} command "${command}":`,
+        llmerror,
+      );
+      llmAnalysis = `LLM analysis failed: ${getErrorMessage(llmerror)}`;
+    }
+    try {
+      finalStdout = await fs.readFile(tempStdoutPath, 'utf-8');
+      finalStderr = await fs.readFile(tempStderrPath, 'utf-8');
+    } catch (err: unknown) {
+      console.error(`Error reading temp output files for PID ${pid}:`, err);
+      fileReadError = `\nWarning: Failed to read temporary output files (${getErrorMessage(err)}). Final output may be incomplete.`;
+    }
+    await this.cleanupTempFiles(tempStdoutPath, tempStderrPath);
+    const truncatedFinalStdout = this.truncateOutput(finalStdout);
+    const truncatedFinalStderr = this.truncateOutput(finalStderr);
+    resolve({
+      llmContent: `Background Command: ${command}\nLaunched in: ${cwd}\nPID: ${pid}\n--- LLM Analysis ---\n${llmAnalysis}\n--- Final Stdout (from ${path.basename(tempStdoutPath)}) ---\n${truncatedFinalStdout}\n--- Final Stderr (from ${path.basename(tempStderrPath)}) ---\n${truncatedFinalStderr}\n--- Launch Stdout ---\n${initialStdout}\n--- Launch Stderr ---\n${initialStderr}${fileReadError}`,
+      returnDisplay: `(PID: ${pid}): ${this.truncateOutput(llmAnalysis, 200)}`,
+    });
+  }
+
+  private async cleanupTempFiles(
+    stdoutPath: string | null,
+    stderrPath: string | null,
+  ): Promise<void> {
+    const unlinkQuietly = async (filePath: string | null) => {
+      if (!filePath) return;
+      try {
+        await fs.unlink(filePath);
+      } catch (err: unknown) {
+        if (!isNodeError(err) || err.code !== 'ENOENT') {
+          console.warn(
+            `Failed to delete temporary file '${filePath}': ${getErrorMessage(err)}`,
+          );
+        }
+      }
+    };
+    await Promise.all([unlinkQuietly(stdoutPath), unlinkQuietly(stderrPath)]);
+  }
+
+  private getCurrentShellCwd(): Promise<string> {
+    return new Promise((resolve, reject) => {
+      if (
+        !this.bashProcess ||
+        !this.bashProcess.stdin?.writable ||
+        this.bashProcess.killed
+      ) {
+        return reject(
+          new Error(
+            'Shell not running, stdin not writable, or killed for PWD check',
+          ),
+        );
+      }
+      const pwdUuid = crypto.randomUUID();
+      const pwdDelimiter = `::PWD_${pwdUuid}::`;
+      let pwdOutput = '';
+      let onPwdData: ((data: Buffer) => void) | null = null;
+      let onPwdError: ((data: Buffer) => void) | null = null;
+      let pwdTimeoutId: NodeJS.Timeout | null = null;
+      let finished = false;
+      const cleanupPwdListeners = (err?: Error) => {
+        if (finished) return;
+        finished = true;
+        if (pwdTimeoutId) clearTimeout(pwdTimeoutId);
+        pwdTimeoutId = null;
+        const stdoutListener = onPwdData;
+        const stderrListener = onPwdError;
+        onPwdData = null;
+        onPwdError = null;
+        if (this.bashProcess && !this.bashProcess.killed) {
+          if (stdoutListener)
+            this.bashProcess.stdout.removeListener('data', stdoutListener);
+          if (stderrListener)
+            this.bashProcess.stderr.removeListener('data', stderrListener);
+        }
+        if (err) {
+          reject(err);
+        } else {
+          resolve(pwdOutput.trim());
+        }
+      };
+      onPwdData = (data: Buffer) => {
+        if (!onPwdData) return;
+        const dataStr = data.toString();
+        const delimiterIndex = dataStr.indexOf(pwdDelimiter);
+        if (delimiterIndex !== -1) {
+          pwdOutput += dataStr.substring(0, delimiterIndex);
+          cleanupPwdListeners();
+        } else {
+          pwdOutput += dataStr;
+        }
+      };
+      onPwdError = (data: Buffer) => {
+        if (!onPwdError) return;
+        const dataStr = data.toString();
+        console.error(`Error during PWD check: ${dataStr}`);
+        cleanupPwdListeners(
+          new Error(
+            `Stderr received during pwd check: ${this.truncateOutput(dataStr, 100)}`,
+          ),
+        );
+      };
+      this.bashProcess.stdout.on('data', onPwdData);
+      this.bashProcess.stderr.on('data', onPwdError);
+      pwdTimeoutId = setTimeout(() => {
+        cleanupPwdListeners(new Error('Timeout waiting for pwd response'));
+      }, 5000);
+      try {
+        const pwdCommand = `printf "%s" "$PWD"; printf "${pwdDelimiter}";\n`;
+        if (this.bashProcess?.stdin?.writable) {
+          this.bashProcess.stdin.write(pwdCommand, (err) => {
+            if (err) {
+              console.error('Error writing pwd command (callback):', err);
+              cleanupPwdListeners(
+                new Error(`Failed to write pwd command: ${err.message}`),
+              );
+            }
+          });
+        } else {
+          throw new Error('Shell stdin not writable for pwd command.');
+        }
+      } catch (e: unknown) {
+        console.error('Exception writing pwd command:', e);
+        cleanupPwdListeners(
+          new Error(`Exception writing pwd command: ${getErrorMessage(e)}`),
+        );
+      }
+    });
+  }
+
+  private truncateOutput(output: string, limit?: number): string {
+    const effectiveLimit = limit ?? this.outputLimit;
+    if (output.length > effectiveLimit) {
       return (
-        output.substring(0, limit) +
-        `\n... [Output truncated at ${limit} characters]`
+        output.substring(0, effectiveLimit) +
+        `\n... [Output truncated at ${effectiveLimit} characters]`
       );
     }
     return output;
   }
+
+  private clearQueue(error: Error) {
+    const queue = this.commandQueue;
+    this.commandQueue = [];
+    queue.forEach(({ resolve, params }) =>
+      resolve({
+        llmContent: `Command cancelled: ${params.command}\nReason: ${error.message}`,
+        returnDisplay: `Command Cancelled: ${error.message}`,
+      }),
+    );
+  }
+
+  destroy() {
+    this.rejectShellReady?.(
+      new Error('BashTool destroyed during initialization or operation.'),
+    );
+    this.rejectShellReady = undefined;
+    this.resolveShellReady = undefined;
+    this.clearQueue(new Error('BashTool is being destroyed.'));
+    try {
+      this.currentCommandCleanup?.();
+    } catch (e) {
+      console.warn('Error during current command cleanup:', e);
+    }
+    if (this.bashProcess) {
+      const proc = this.bashProcess;
+      const pid = proc.pid;
+      this.bashProcess = null;
+      proc.stdout?.removeAllListeners();
+      proc.stderr?.removeAllListeners();
+      proc.removeAllListeners('error');
+      proc.removeAllListeners('close');
+      proc.stdin?.end();
+      try {
+        proc.kill('SIGTERM');
+        setTimeout(() => {
+          if (!proc.killed) {
+            proc.kill('SIGKILL');
+          }
+        }, 500);
+      } catch (e: unknown) {
+        console.warn(
+          `Error trying to kill bash process PID: ${pid}: ${getErrorMessage(e)}`,
+        );
+      }
+    }
+  }
 }