feat: Improve agent session lifeycle and bump SDKs (#1089)

1. Share mock node environment across sessions instead of creating/deleting per-session
  2. Cache machine encryption key to avoid repeated scrypt derivation
  3. Simplify process tree kill to SIGKILL directly without SIGTERM fallback
  4. Promote codex-acp stderr to warn-level logging
  5. Bump codex-acp (0.9.5), claude-agent-sdk (0.2.63), anthropic sdk (0.78.0)

Author: charlesvien

apps/twig/scripts/download-binaries.mjs

@@ -19,7 +19,7 @@ const DEST_DIR = join(__dirname, "..", "resources", "codex-acp");
 const BINARIES = [
   {
     name: "codex-acp",
-    version: "0.9.1",
+    version: "0.9.5",
     getUrl: (version, target) => {
       const ext = target.includes("windows") ? "zip" : "tar.gz";
       return `https://github.com/zed-industries/codex-acp/releases/download/v${version}/codex-acp-${version}-${target}.${ext}`;

apps/twig/src/main/services/agent/service.ts

@@ -1,6 +1,6 @@
-import fs, { mkdirSync, rmSync, symlinkSync } from "node:fs";
+import fs, { existsSync, mkdirSync, symlinkSync } from "node:fs";
 import { tmpdir } from "node:os";
-import { isAbsolute, join, relative, resolve, sep } from "node:path";
+import { delimiter, isAbsolute, join, relative, resolve, sep } from "node:path";
 import {
   type Client,
   ClientSideConnection,
@@ -46,6 +46,8 @@ export type { InterruptReason };
 
 const log = logger.scope("agent-service");
 
+const SHARED_MOCK_NODE_DIR = join(tmpdir(), "agent-node-shared");
+
 /** Mark all content blocks as hidden so the renderer doesn't show a duplicate user message on retry. */
 function hidePromptBlocks(prompt: ContentBlock[]): ContentBlock[] {
   return prompt.map((block) => {
@@ -201,7 +203,6 @@ interface ManagedSession {
   channel: string;
   createdAt: number;
   lastActivityAt: number;
-  mockNodeDir: string;
   config: SessionConfig;
   interruptReason?: InterruptReason;
   needsRecreation: boolean;
@@ -246,6 +247,7 @@ export class AgentService extends TypedEventEmitter<AgentServiceEvents> {
   private sessions = new Map<string, ManagedSession>();
   private currentToken: string | null = null;
   private pendingPermissions = new Map<string, PendingPermission>();
+  private mockNodeReady = false;
   private processTracking: ProcessTrackingService;
   private sleepService: SleepService;
   private fsService: FsService;
@@ -494,7 +496,7 @@ export class AgentService extends TypedEventEmitter<AgentServiceEvents> {
     }
 
     const channel = `agent-event:${taskRunId}`;
-    const mockNodeDir = this.setupMockNodeEnvironment(taskRunId);
+    const mockNodeDir = this.setupMockNodeEnvironment();
     this.setupEnvironment(credentials, mockNodeDir);
 
     // Preview sessions don't persist logs — no real task exists
@@ -658,7 +660,6 @@ export class AgentService extends TypedEventEmitter<AgentServiceEvents> {
         channel,
         createdAt: Date.now(),
         lastActivityAt: Date.now(),
-        mockNodeDir,
         config,
         needsRecreation: false,
         promptPending: false,
@@ -676,7 +677,7 @@ export class AgentService extends TypedEventEmitter<AgentServiceEvents> {
       } catch {
         log.debug("Agent cleanup failed during error handling", { taskRunId });
       }
-      this.cleanupMockNodeEnvironment(mockNodeDir);
+
       if (!isRetry && isAuthError(err)) {
         log.warn(
           `Auth error during ${isReconnect ? "reconnect" : "create"}, retrying`,
@@ -1003,8 +1004,10 @@ For git operations while detached:
     mockNodeDir: string,
   ): void {
     const token = this.getToken(credentials.apiKey);
-    const newPath = `${mockNodeDir}:${process.env.PATH || ""}`;
-    process.env.PATH = newPath;
+    const currentPath = process.env.PATH || "";
+    if (!currentPath.split(delimiter).includes(mockNodeDir)) {
+      process.env.PATH = `${mockNodeDir}${delimiter}${currentPath}`;
+    }
     process.env.POSTHOG_AUTH_HEADER = `Bearer ${token}`;
     process.env.ANTHROPIC_API_KEY = token;
     process.env.ANTHROPIC_AUTH_TOKEN = token;
@@ -1026,29 +1029,20 @@ For git operations while detached:
     process.env.POSTHOG_PROJECT_ID = String(credentials.projectId);
   }
 
-  private setupMockNodeEnvironment(sessionId: string): string {
-    const mockNodeDir = join(tmpdir(), `array-agent-node-${sessionId}`);
-    try {
-      mkdirSync(mockNodeDir, { recursive: true });
-      const nodeSymlinkPath = join(mockNodeDir, "node");
+  private setupMockNodeEnvironment(): string {
+    if (!this.mockNodeReady) {
       try {
-        rmSync(nodeSymlinkPath, { force: true });
-      } catch {
-        /* ignore */
+        mkdirSync(SHARED_MOCK_NODE_DIR, { recursive: true });
+        const nodeSymlinkPath = join(SHARED_MOCK_NODE_DIR, "node");
+        if (!existsSync(nodeSymlinkPath)) {
+          symlinkSync(process.execPath, nodeSymlinkPath);
+        }
+        this.mockNodeReady = true;
+      } catch (err) {
+        log.warn("Failed to setup mock node environment", err);
       }
-      symlinkSync(process.execPath, nodeSymlinkPath);
-    } catch (err) {
-      log.warn("Failed to setup mock node environment", err);
-    }
-    return mockNodeDir;
-  }
-
-  private cleanupMockNodeEnvironment(mockNodeDir: string): void {
-    try {
-      rmSync(mockNodeDir, { recursive: true, force: true });
-    } catch {
-      /* ignore */
     }
+    return SHARED_MOCK_NODE_DIR;
   }
 
   private async cleanupSession(taskRunId: string): Promise<void> {
@@ -1060,7 +1054,7 @@ For git operations while detached:
       } catch {
         log.debug("Agent cleanup failed", { taskRunId });
       }
-      this.cleanupMockNodeEnvironment(session.mockNodeDir);
+
       this.sessions.delete(taskRunId);
     }
   }

apps/twig/src/main/utils/encryption.ts

@@ -8,10 +8,15 @@ import { machineIdSync } from "node-machine-id";
 const APP_SALT = "array-v1";
 const ENCRYPTION_VERSION = 1;
 
+let cachedMachineKey: Buffer | undefined;
+
 function getMachineKey(): Buffer {
-  const machineId = machineIdSync();
-  const identifier = [machineId, os.platform(), os.arch()].join("|");
-  return crypto.scryptSync(identifier, APP_SALT, 32);
+  if (!cachedMachineKey) {
+    const machineId = machineIdSync();
+    const identifier = [machineId, os.platform(), os.arch()].join("|");
+    cachedMachineKey = crypto.scryptSync(identifier, APP_SALT, 32);
+  }
+  return cachedMachineKey;
 }
 
 export function encrypt(plaintext: string): string {

apps/twig/src/main/utils/process-utils.ts

@@ -4,6 +4,8 @@ import { logger } from "./logger.js";
 
 const log = logger.scope("process-utils");
 
+const SIGKILL_GRACE_MS = 5_000;
+
 /**
  * Kill a process and all its children by killing the process group.
  * On Unix, we use process.kill(-pid) to kill the entire process group.
@@ -15,21 +17,29 @@ export function killProcessTree(pid: number): void {
       // Windows: use taskkill with /T to kill process tree
       execSync(`taskkill /PID ${pid} /T /F`, { stdio: "ignore" });
     } else {
-      // Try process group first (-pid), fall back to individual process (pid).
-      // SIGTERM for graceful shutdown, SIGKILL as last resort.
-      const signals: Array<[number, NodeJS.Signals]> = [
-        [-pid, "SIGTERM"],
-        [-pid, "SIGKILL"],
-        [pid, "SIGTERM"],
-        [pid, "SIGKILL"],
-      ];
-      for (const [target, signal] of signals) {
+      // SIGTERM the process group first, fall back to individual process
+      let sent = false;
+      for (const target of [-pid, pid]) {
         try {
-          process.kill(target, signal);
-          return;
+          process.kill(target, "SIGTERM");
+          sent = true;
+          break;
         } catch {}
       }
-      log.warn(`Failed to kill process ${pid}`);
+
+      if (!sent) return;
+
+      // Force kill after a grace period — unref so the timer doesn't delay app exit.
+      // We skip the liveness check since isProcessAlive only tests the group leader;
+      // orphaned children in the same group would be missed. The catch blocks
+      // handle ESRCH if everything already exited.
+      setTimeout(() => {
+        for (const target of [-pid, pid]) {
+          try {
+            process.kill(target, "SIGKILL");
+          } catch {}
+        }
+      }, SIGKILL_GRACE_MS).unref();
     }
   } catch (err) {
     log.warn(`Failed to kill process tree for PID ${pid}`, err);

packages/agent/package.json

@@ -85,8 +85,8 @@
   },
   "dependencies": {
     "@agentclientprotocol/sdk": "^0.14.0",
-    "@anthropic-ai/claude-agent-sdk": "0.2.59",
-    "@anthropic-ai/sdk": "^0.71.0",
+    "@anthropic-ai/claude-agent-sdk": "0.2.63",
+    "@anthropic-ai/sdk": "^0.78.0",
     "@hono/node-server": "^1.19.9",
     "@opentelemetry/api-logs": "^0.208.0",
     "@opentelemetry/exporter-logs-otlp-http": "^0.208.0",

packages/agent/src/adapters/claude/conversion/sdk-to-acp.ts

@@ -257,6 +257,8 @@ function processContentChunk(
     case "citations_delta":
     case "signature_delta":
     case "container_upload":
+    case "compaction":
+    case "compaction_delta":
       return null;
 
     default:

packages/agent/src/adapters/codex/spawn.ts

@@ -1,5 +1,6 @@
 import { type ChildProcess, spawn } from "node:child_process";
 import { existsSync } from "node:fs";
+import { delimiter, dirname } from "node:path";
 import type { Readable, Writable } from "node:stream";
 import type { ProcessSpawnedCallback } from "../../types.js";
 import { Logger } from "../../utils/logger.js";
@@ -79,8 +80,8 @@ export function spawnCodexProcess(options: CodexProcessOptions): CodexProcess {
   const { command, args } = findCodexBinary(options);
 
   if (options.binaryPath && existsSync(options.binaryPath)) {
-    const binDir = options.binaryPath.replace(/\/[^/]+$/, "");
-    env.PATH = `${binDir}:${env.PATH ?? ""}`;
+    const binDir = dirname(options.binaryPath);
+    env.PATH = `${binDir}${delimiter}${env.PATH ?? ""}`;
   }
 
   logger.info("Spawning codex-acp process", {
@@ -100,7 +101,7 @@ export function spawnCodexProcess(options: CodexProcessOptions): CodexProcess {
   });
 
   child.stderr?.on("data", (data: Buffer) => {
-    logger.debug("codex-acp stderr:", data.toString());
+    logger.error("codex-acp stderr:", data.toString());
   });
 
   child.on("error", (err) => {

packages/agent/src/test/mocks/claude-sdk.ts

@@ -99,6 +99,7 @@ export function createMockQuery(
     initializationResult: vi.fn().mockResolvedValue({}),
     reconnectMcpServer: vi.fn().mockResolvedValue(undefined),
     toggleMcpServer: vi.fn().mockResolvedValue(undefined),
+    supportedAgents: vi.fn().mockResolvedValue([]),
     stopTask: vi.fn().mockResolvedValue(undefined),
     [Symbol.asyncDispose]: vi.fn().mockResolvedValue(undefined),
     _abortController: abortController,
@@ -176,6 +177,9 @@ export function createSuccessResult(
       },
       server_tool_use: { web_search_requests: 0, web_fetch_requests: 0 },
       service_tier: "standard",
+      inference_geo: "us",
+      iterations: [],
+      speed: "standard",
     },
     modelUsage: {},
     permission_denials: [],
@@ -209,6 +213,9 @@ export function createErrorResult(
       },
       server_tool_use: { web_search_requests: 0, web_fetch_requests: 0 },
       service_tier: "standard",
+      inference_geo: "us",
+      iterations: [],
+      speed: "standard",
     },
     modelUsage: {},
     permission_denials: [],