diff --git a/src/browser/chrome.ts b/src/browser/chrome.ts
index 6f610bcc4..f7dab5796 100644
--- a/src/browser/chrome.ts
+++ b/src/browser/chrome.ts
@@ -4,6 +4,7 @@ import os from "node:os";
 import path from "node:path";
 import WebSocket from "ws";
 
+import { registerChild } from "../infra/child-registry.js";
 import { ensurePortAvailable } from "../infra/ports.js";
 import { createSubsystemLogger } from "../logging/subsystem.js";
 import { CONFIG_DIR } from "../utils.js";
@@ -263,6 +264,9 @@ export async function launchClawdChrome(
   }
 
   const proc = spawnOnce();
+  // Register with child registry (managedExternally: true because browser has its own close logic)
+  // Note: Only register the main proc, NOT the bootstrap process (which is short-lived)
+  registerChild("chrome-browser", proc, { managedExternally: true });
   // Wait for CDP to come up.
   const readyDeadline = Date.now() + 15_000;
   while (Date.now() < readyDeadline) {
diff --git a/src/cli/gateway-cli/backoff.test.ts b/src/cli/gateway-cli/backoff.test.ts
new file mode 100644
index 000000000..3af4bafc2
--- /dev/null
+++ b/src/cli/gateway-cli/backoff.test.ts
@@ -0,0 +1,48 @@
+// src/cli/gateway-cli/backoff.test.ts
+import { describe, it, expect } from "vitest";
+import { calculateBackoffMs, applyJitter } from "./backoff.js";
+
+describe("calculateBackoffMs", () => {
+  it("returns 0 for zero consecutive failures", () => {
+    expect(calculateBackoffMs(0)).toBe(0);
+  });
+
+  it("returns 2000ms for first failure", () => {
+    expect(calculateBackoffMs(1)).toBe(2000);
+  });
+
+  it("returns 4000ms for second failure", () => {
+    expect(calculateBackoffMs(2)).toBe(4000);
+  });
+
+  it("returns 32000ms for fifth failure", () => {
+    expect(calculateBackoffMs(5)).toBe(32000);
+  });
+
+  it("caps at 60000ms for high failure counts", () => {
+    expect(calculateBackoffMs(10)).toBe(60000);
+    expect(calculateBackoffMs(100)).toBe(60000);
+  });
+});
+
+describe("applyJitter", () => {
+  it("returns 0 for 0 input", () => {
+    expect(applyJitter(0)).toBe(0);
+  });
+
+  it("returns value within +/- 10% of input", () => {
+    const input = 10000;
+    const minExpected = Math.floor(input * 0.9);
+    const maxExpected = Math.ceil(input * 1.1);
+    for (let i = 0; i < 100; i++) {
+      const result = applyJitter(input);
+      expect(result).toBeGreaterThanOrEqual(minExpected);
+      expect(result).toBeLessThanOrEqual(maxExpected);
+    }
+  });
+
+  it("returns an integer", () => {
+    const result = applyJitter(2000);
+    expect(Number.isInteger(result)).toBe(true);
+  });
+});
diff --git a/src/cli/gateway-cli/backoff.ts b/src/cli/gateway-cli/backoff.ts
new file mode 100644
index 000000000..b52a77b82
--- /dev/null
+++ b/src/cli/gateway-cli/backoff.ts
@@ -0,0 +1,30 @@
+// src/cli/gateway-cli/backoff.ts
+
+const BASE_BACKOFF_MS = 2000;
+const MAX_BACKOFF_MS = 60_000;
+const JITTER_FACTOR = 0.1; // +/- 10%
+
+/**
+ * Calculate exponential backoff based on consecutive failures.
+ * Formula: min(BASE * 2^(failures-1), MAX)
+ *
+ * @param consecutiveFailures - Number of consecutive failures (0 = no backoff)
+ * @returns Backoff duration in milliseconds
+ */
+export function calculateBackoffMs(consecutiveFailures: number): number {
+  if (consecutiveFailures <= 0) return 0;
+  const exponential = BASE_BACKOFF_MS * Math.pow(2, consecutiveFailures - 1);
+  return Math.min(exponential, MAX_BACKOFF_MS);
+}
+
+/**
+ * Apply random jitter to a backoff value to prevent thundering herd.
+ *
+ * @param baseMs - Base backoff in milliseconds
+ * @returns Backoff with +/- 10% jitter applied, rounded to integer
+ */
+export function applyJitter(baseMs: number): number {
+  if (baseMs <= 0) return 0;
+  const jitter = (Math.random() - 0.5) * 2 * JITTER_FACTOR * baseMs;
+  return Math.round(baseMs + jitter);
+}
diff --git a/src/cli/gateway-cli/crash-tracker.test.ts b/src/cli/gateway-cli/crash-tracker.test.ts
new file mode 100644
index 000000000..89a4b426c
--- /dev/null
+++ b/src/cli/gateway-cli/crash-tracker.test.ts
@@ -0,0 +1,109 @@
+// src/cli/gateway-cli/crash-tracker.test.ts
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import {
+  recordCrash,
+  getRecentCrashes,
+  getCrashesInLastHour,
+  clearCrashes,
+  classifyError,
+} from "./crash-tracker.js";
+
+describe("crash-tracker", () => {
+  beforeEach(() => {
+    clearCrashes();
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("records a crash with timestamp", () => {
+    vi.setSystemTime(new Date("2026-01-29T12:00:00Z"));
+    recordCrash({
+      errorType: "fetch_failed",
+      errorMessage: "ECONNREFUSED",
+      uptimeMs: 5000,
+      backoffMs: 2000,
+      consecutiveFailures: 1,
+    });
+
+    const crashes = getRecentCrashes();
+    expect(crashes).toHaveLength(1);
+    expect(crashes[0].timestamp).toBe(Date.now());
+    expect(crashes[0].errorType).toBe("fetch_failed");
+  });
+
+  it("limits to MAX_CRASH_HISTORY entries", () => {
+    for (let i = 0; i < 25; i++) {
+      recordCrash({
+        errorType: "network_error",
+        errorMessage: `Error ${i}`,
+        uptimeMs: 0,
+        backoffMs: 2000,
+        consecutiveFailures: i + 1,
+      });
+    }
+
+    const crashes = getRecentCrashes();
+    expect(crashes).toHaveLength(20);
+    expect(crashes[0].errorMessage).toBe("Error 5"); // First 5 were dropped
+  });
+
+  it("counts crashes in last hour correctly", () => {
+    vi.setSystemTime(new Date("2026-01-29T12:00:00Z"));
+    recordCrash({
+      errorType: "fetch_failed",
+      errorMessage: "a",
+      uptimeMs: 0,
+      backoffMs: 2000,
+      consecutiveFailures: 1,
+    });
+
+    vi.setSystemTime(new Date("2026-01-29T12:30:00Z"));
+    recordCrash({
+      errorType: "fetch_failed",
+      errorMessage: "b",
+      uptimeMs: 0,
+      backoffMs: 4000,
+      consecutiveFailures: 2,
+    });
+
+    // At 13:29:59, "a" is 89 min old (outside), "b" is 59 min old (inside)
+    vi.setSystemTime(new Date("2026-01-29T13:29:59Z"));
+    expect(getCrashesInLastHour()).toBe(1); // Only "b" is within last hour
+  });
+});
+
+describe("classifyError", () => {
+  it("classifies fetch failed errors", () => {
+    expect(classifyError(new Error("TypeError: fetch failed"))).toBe("fetch_failed");
+    expect(classifyError(new Error("connect ECONNREFUSED 127.0.0.1:443"))).toBe("fetch_failed");
+  });
+
+  it("classifies network errors", () => {
+    expect(classifyError(new Error("read ECONNRESET"))).toBe("network_error");
+    expect(classifyError(new Error("connect ETIMEDOUT"))).toBe("network_error");
+    expect(classifyError(new Error("network unreachable"))).toBe("network_error");
+  });
+
+  it("classifies startup errors", () => {
+    expect(classifyError(new Error("startup failed: missing config"))).toBe("startup_error");
+    expect(classifyError(new Error("init error: bad credentials"))).toBe("startup_error");
+  });
+
+  it("defaults to runtime_error for unrecognized errors", () => {
+    expect(classifyError(new Error("something went wrong"))).toBe("runtime_error");
+    expect(classifyError(new Error("unexpected condition"))).toBe("runtime_error");
+  });
+
+  it("handles null/undefined safely", () => {
+    expect(classifyError(null)).toBe("unknown");
+    expect(classifyError(undefined)).toBe("unknown");
+  });
+
+  it("handles non-Error objects", () => {
+    expect(classifyError("string error")).toBe("runtime_error");
+    expect(classifyError({ message: "object error" })).toBe("runtime_error");
+  });
+});
diff --git a/src/cli/gateway-cli/crash-tracker.ts b/src/cli/gateway-cli/crash-tracker.ts
new file mode 100644
index 000000000..7fdaeb27a
--- /dev/null
+++ b/src/cli/gateway-cli/crash-tracker.ts
@@ -0,0 +1,102 @@
+// src/cli/gateway-cli/crash-tracker.ts
+import { createSubsystemLogger } from "../../logging/subsystem.js";
+import { isTransientNetworkError } from "../../infra/unhandled-rejections.js";
+
+const log = createSubsystemLogger("gateway");
+
+export type CrashErrorType =
+  | "fetch_failed"
+  | "network_error"
+  | "startup_error"
+  | "runtime_error"
+  | "unknown";
+
+export type CrashRecord = {
+  timestamp: number;
+  errorType: CrashErrorType;
+  errorMessage: string;
+  uptimeMs: number;
+  backoffMs: number;
+  consecutiveFailures: number;
+};
+
+const MAX_CRASH_HISTORY = 20;
+const recentCrashes: CrashRecord[] = [];
+
+export function recordCrash(record: Omit<CrashRecord, "timestamp">): void {
+  const full: CrashRecord = { ...record, timestamp: Date.now() };
+  recentCrashes.push(full);
+  if (recentCrashes.length > MAX_CRASH_HISTORY) {
+    recentCrashes.shift();
+  }
+
+  log.error("gateway_crash", {
+    errorType: record.errorType,
+    errorMessage: record.errorMessage,
+    uptimeMs: record.uptimeMs,
+    backoffMs: record.backoffMs,
+    consecutiveFailures: record.consecutiveFailures,
+    crashesInLastHour: getCrashesInLastHour(),
+  });
+}
+
+export function getRecentCrashes(): readonly CrashRecord[] {
+  return recentCrashes;
+}
+
+export function getCrashesInLastHour(): number {
+  const oneHourAgo = Date.now() - 3600_000;
+  return recentCrashes.filter((c) => c.timestamp > oneHourAgo).length;
+}
+
+export function clearCrashes(): void {
+  recentCrashes.length = 0;
+}
+
+// Network error patterns to match in error messages
+const FETCH_FAILED_PATTERNS = ["fetch failed", "econnrefused"];
+const NETWORK_ERROR_PATTERNS = [
+  "econnreset",
+  "etimedout",
+  "enotfound",
+  "ehostunreach",
+  "enetunreach",
+  "network unreachable",
+  "socket hang up",
+];
+
+function getErrorMessage(err: unknown): string {
+  if (err instanceof Error) return err.message;
+  if (typeof err === "string") return err;
+  if (err && typeof err === "object" && "message" in err && typeof err.message === "string") {
+    return err.message;
+  }
+  return "";
+}
+
+export function classifyError(err: unknown): CrashErrorType {
+  if (!err) return "unknown";
+
+  const message = getErrorMessage(err).toLowerCase();
+
+  // Use existing transient network detection for consistency
+  if (isTransientNetworkError(err)) {
+    if (FETCH_FAILED_PATTERNS.some((p) => message.includes(p))) {
+      return "fetch_failed";
+    }
+    return "network_error";
+  }
+
+  // Also check message patterns for errors without proper error codes
+  if (FETCH_FAILED_PATTERNS.some((p) => message.includes(p))) {
+    return "fetch_failed";
+  }
+  if (NETWORK_ERROR_PATTERNS.some((p) => message.includes(p))) {
+    return "network_error";
+  }
+
+  if (message.includes("startup") || message.includes("init")) {
+    return "startup_error";
+  }
+  return "runtime_error";
+}
diff --git a/src/cli/gateway-cli/run-loop.ts b/src/cli/gateway-cli/run-loop.ts
index 358d9a3cb..131b57468 100644
--- a/src/cli/gateway-cli/run-loop.ts
+++ b/src/cli/gateway-cli/run-loop.ts
@@ -4,8 +4,12 @@ import {
   consumeGatewaySigusr1RestartAuthorization,
   isGatewaySigusr1RestartExternallyAllowed,
 } from "../../infra/restart.js";
+import { isTransientNetworkError } from "../../infra/unhandled-rejections.js";
 import { createSubsystemLogger } from "../../logging/subsystem.js";
 import type { defaultRuntime } from "../../runtime.js";
+import { calculateBackoffMs, applyJitter } from "./backoff.js";
+import { recordCrash, classifyError } from "./crash-tracker.js";
+import { killAllChildrenSync } from "../../infra/child-registry.js";
 
 const gatewayLog = createSubsystemLogger("gateway");
 
@@ -18,7 +22,7 @@ export async function runGatewayLoop(params: {
   const lock = await acquireGatewayLock();
   let server: Awaited<ReturnType<typeof startGatewayServer>> | null = null;
   let shuttingDown = false;
-  let restartResolver: (() => void) | null = null;
+  let restartResolver: ((reason: { isUserInitiated: boolean }) => void) | null = null;
 
   const cleanupSignals = () => {
     process.removeListener("SIGTERM", onSigterm);
@@ -54,7 +58,7 @@ export async function runGatewayLoop(params: {
         server = null;
         if (isRestart) {
           shuttingDown = false;
-          restartResolver?.();
+          restartResolver?.({ isUserInitiated: action === "restart" });
         } else {
           cleanupSignals();
           params.runtime.exit(0);
@@ -87,15 +91,83 @@ export async function runGatewayLoop(params: {
   process.on("SIGINT", onSigint);
   process.on("SIGUSR1", onSigusr1);
 
+  // Register exit handler for crash scenarios (sync only - can't await in 'exit' handler)
+  process.on("exit", () => {
+    killAllChildrenSync();
+  });
+
+  let consecutiveFailures = 0;
+  const STABILITY_THRESHOLD_MS = 60_000;
+
   try {
     // Keep process alive; SIGUSR1 triggers an in-process restart (no supervisor required).
     // SIGTERM/SIGINT still exit after a graceful shutdown.
     // eslint-disable-next-line no-constant-condition
     while (true) {
-      server = await params.start();
-      await new Promise<void>((resolve) => {
+      // Calculate and apply backoff with jitter
+      const baseBackoffMs = calculateBackoffMs(consecutiveFailures);
+      const backoffMs = applyJitter(baseBackoffMs);
+
+      if (backoffMs > 0) {
+        gatewayLog.warn(
+          `Restarting gateway in ${backoffMs}ms after failure (attempt ${consecutiveFailures + 1})`,
+        );
+        await new Promise((resolve) => setTimeout(resolve, backoffMs));
+      }
+
+      const startAttemptMs = Date.now();
+
+      try {
+        server = await params.start();
+      } catch (err) {
+        // Only retry transient network errors; rethrow fatal/config errors
+        if (!isTransientNetworkError(err)) {
+          throw err;
+        }
+        gatewayLog.error(`Gateway startup failed (transient): ${String(err)}`);
+        recordCrash({
+          errorType: classifyError(err),
+          errorMessage: err instanceof Error ? err.message : String(err),
+          uptimeMs: 0,
+          backoffMs,
+          consecutiveFailures: consecutiveFailures + 1,
+        });
+        consecutiveFailures++;
+        continue;
+      }
+
+      // Server started successfully - wait for restart signal
+      const restartReason = await new Promise<{ isUserInitiated: boolean }>((resolve) => {
         restartResolver = resolve;
       });
+
+      const uptimeMs = Date.now() - startAttemptMs;
+
+      // Determine backoff reset behavior based on uptime and restart type
+      if (restartReason.isUserInitiated) {
+        // User-initiated restart (SIGUSR1): no backoff
+        consecutiveFailures = 0;
+      } else if (uptimeMs >= STABILITY_THRESHOLD_MS) {
+        // Crashed after stable uptime: reset to minimal backoff
+        recordCrash({
+          errorType: "runtime_error",
+          errorMessage: "crashed after stable uptime",
+          uptimeMs,
+          backoffMs: calculateBackoffMs(1),
+          consecutiveFailures: 1,
+        });
+        consecutiveFailures = 1;
+      } else {
+        // Crashed during startup or early runtime: increment backoff
+        recordCrash({
+          errorType: "runtime_error",
+          errorMessage: "crashed during early runtime",
+          uptimeMs,
+          backoffMs: calculateBackoffMs(consecutiveFailures + 1),
+          consecutiveFailures: consecutiveFailures + 1,
+        });
+        consecutiveFailures++;
+      }
     }
   } finally {
     await lock?.release();
diff --git a/src/gateway/server-close.ts b/src/gateway/server-close.ts
index da9f5a39e..9977c0a3c 100644
--- a/src/gateway/server-close.ts
+++ b/src/gateway/server-close.ts
@@ -3,6 +3,7 @@ import type { WebSocketServer } from "ws";
 import type { CanvasHostHandler, CanvasHostServer } from "../canvas-host/server.js";
 import { type ChannelId, listChannelPlugins } from "../channels/plugins/index.js";
 import { stopGmailWatcher } from "../hooks/gmail-watcher.js";
+import { killAllChildren, killAllChildrenSync } from "../infra/child-registry.js";
 import type { HeartbeatRunner } from "../infra/heartbeat-runner.js";
 import type { PluginServicesHandle } from "../plugins/services.js";
 
@@ -124,5 +125,11 @@ export function createGatewayCloseHandler(params: {
         httpServer.close((err) => (err ? reject(err) : resolve())),
       );
     }
+
+    // Phase 3: Kill any orphaned children not stopped by their own managers
+    await killAllChildren("SIGTERM", { excludeManaged: true, timeoutMs: 2000 });
+
+    // Phase 4: Force cleanup of any remaining children
+    killAllChildrenSync();
   };
 }
diff --git a/src/hooks/gmail-watcher.ts b/src/hooks/gmail-watcher.ts
index bf1b08b35..ad9093eb9 100644
--- a/src/hooks/gmail-watcher.ts
+++ b/src/hooks/gmail-watcher.ts
@@ -8,6 +8,7 @@
 import { type ChildProcess, spawn } from "node:child_process";
 import { hasBinary } from "../agents/skills.js";
 import type { MoltbotConfig } from "../config/config.js";
+import { registerChild } from "../infra/child-registry.js";
 import { createSubsystemLogger } from "../logging/subsystem.js";
 import { runCommandWithTimeout } from "../process/exec.js";
 import {
@@ -73,6 +74,9 @@ function spawnGogServe(cfg: GmailHookRuntimeConfig): ChildProcess {
     detached: false,
   });
 
+  // Register with child registry (managedExternally: true because we have our own stop logic)
+  registerChild("gog-gmail-watcher", child, { managedExternally: true });
+
   child.stdout?.on("data", (data: Buffer) => {
     const line = data.toString().trim();
     if (line) log.info(`[gog] ${line}`);
diff --git a/src/infra/child-registry.test.ts b/src/infra/child-registry.test.ts
new file mode 100644
index 000000000..b66fcc90d
--- /dev/null
+++ b/src/infra/child-registry.test.ts
@@ -0,0 +1,136 @@
+// src/infra/child-registry.test.ts
+import { describe, it, expect, beforeEach, vi, afterEach } from "vitest";
+import { spawn, type ChildProcess } from "node:child_process";
+import {
+  registerChild,
+  unregisterChild,
+  killAllChildren,
+  killAllChildrenSync,
+  getRegisteredChildren,
+  clearRegistry,
+} from "./child-registry.js";
+
+describe("child-registry", () => {
+  beforeEach(() => {
+    clearRegistry();
+  });
+
+  afterEach(() => {
+    clearRegistry();
+  });
+
+  it("registers a child process with PID", () => {
+    const mockProc = {
+      pid: 12345,
+      killed: false,
+      exitCode: null,
+      signalCode: null,
+      kill: vi.fn(),
+      on: vi.fn(),
+      once: vi.fn(),
+    } as unknown as ChildProcess;
+
+    registerChild("test-child", mockProc);
+
+    const children = getRegisteredChildren();
+    expect(children).toHaveLength(1);
+    expect(children[0].pid).toBe(12345);
+    expect(children[0].name).toBe("test-child");
+  });
+
+  it("does not register if no PID", () => {
+    const mockProc = {
+      pid: undefined,
+      on: vi.fn(),
+    } as unknown as ChildProcess;
+
+    registerChild("no-pid", mockProc);
+
+    expect(getRegisteredChildren()).toHaveLength(0);
+  });
+
+  it("respects managedExternally flag", () => {
+    const mockProc = {
+      pid: 11111,
+      killed: false,
+      exitCode: null,
+      signalCode: null,
+      kill: vi.fn(),
+      on: vi.fn(),
+      once: vi.fn(),
+    } as unknown as ChildProcess;
+
+    registerChild("managed", mockProc, { managedExternally: true });
+
+    const children = getRegisteredChildren();
+    expect(children[0].managedExternally).toBe(true);
+  });
+
+  it("unregisters a child by PID", () => {
+    const mockProc = {
+      pid: 22222,
+      killed: false,
+      exitCode: null,
+      signalCode: null,
+      kill: vi.fn(),
+      on: vi.fn(),
+      once: vi.fn(),
+    } as unknown as ChildProcess;
+
+    registerChild("to-remove", mockProc);
+    expect(getRegisteredChildren()).toHaveLength(1);
+
+    unregisterChild(22222);
+    expect(getRegisteredChildren()).toHaveLength(0);
+  });
+
+  it("killAllChildrenSync sends SIGKILL to all children", () => {
+    const killFn = vi.fn();
+    const mockProc = {
+      pid: 33333,
+      killed: false,
+      exitCode: null,
+      signalCode: null,
+      kill: killFn,
+      on: vi.fn(),
+      once: vi.fn(),
+    } as unknown as ChildProcess;
+
+    registerChild("to-kill", mockProc);
+    killAllChildrenSync();
+
+    expect(killFn).toHaveBeenCalledWith("SIGKILL");
+  });
+
+  it("skips already-dead processes", () => {
+    const killFn = vi.fn();
+    const mockProc = {
+      pid: 44444,
+      killed: false,
+      exitCode: 0, // Already exited
+      signalCode: null,
+      kill: killFn,
+      on: vi.fn(),
+      once: vi.fn(),
+    } as unknown as ChildProcess;
+
+    registerChild("already-dead", mockProc);
+    killAllChildrenSync();
+
+    expect(killFn).not.toHaveBeenCalled();
+  });
+});
+
+describe("child-registry integration", () => {
+  it("kills a real spawned process", async () => {
+    const proc = spawn("sleep", ["60"], { detached: false });
+    registerChild("sleep-test", proc);
+
+    expect(getRegisteredChildren()).toHaveLength(1);
+
+    await killAllChildren("SIGTERM", { timeoutMs: 1000 });
+
+    // Process should be killed
+    expect(proc.killed || proc.exitCode !== null || proc.signalCode !== null).toBe(true);
+  });
+});
diff --git a/src/infra/child-registry.ts b/src/infra/child-registry.ts
new file mode 100644
index 000000000..d09012401
--- /dev/null
+++ b/src/infra/child-registry.ts
@@ -0,0 +1,153 @@
+// src/infra/child-registry.ts
+import type { ChildProcess } from "node:child_process";
+import { createSubsystemLogger } from "../logging/subsystem.js";
+
+const log = createSubsystemLogger("child-registry");
+
+type ChildEntry = {
+  name: string;
+  process: ChildProcess;
+  managedExternally: boolean;
+};
+
+const children = new Map<number, ChildEntry>();
+
+export function registerChild(
+  name: string,
+  proc: ChildProcess,
+  opts?: { managedExternally?: boolean },
+): void {
+  if (!proc.pid) {
+    log.warn(`Cannot register child "${name}": no PID (spawn may have failed)`);
+    return;
+  }
+
+  children.set(proc.pid, {
+    name,
+    process: proc,
+    managedExternally: opts?.managedExternally ?? false,
+  });
+
+  const cleanup = () => {
+    if (proc.pid) children.delete(proc.pid);
+  };
+  proc.on("exit", cleanup);
+  proc.on("error", cleanup);
+}
+
+export function unregisterChild(pid: number): void {
+  children.delete(pid);
+}
+
+export async function killAllChildren(
+  signal: NodeJS.Signals = "SIGTERM",
+  opts?: { excludeManaged?: boolean; timeoutMs?: number },
+): Promise<void> {
+  const timeoutMs = opts?.timeoutMs ?? (signal === "SIGKILL" ? 500 : 3000);
+  const excludeManaged = opts?.excludeManaged ?? false;
+  const promises: Promise<void>[] = [];
+
+  // Copy entries to avoid mutation during iteration
+  const entries = [...children.entries()];
+  for (const [pid, entry] of entries) {
+    const { name, process: proc, managedExternally } = entry;
+
+    if (excludeManaged && managedExternally) {
+      continue;
+    }
+
+    if (proc.killed || proc.exitCode !== null || proc.signalCode !== null) {
+      children.delete(pid);
+      continue;
+    }
+
+    log.info(`Killing child process: ${name} (pid=${pid}) with ${signal}`);
+    promises.push(killWithTimeout(pid, proc, signal, timeoutMs, name));
+  }
+
+  await Promise.all(promises);
+}
+
+async function killWithTimeout(
+  pid: number,
+  proc: ChildProcess,
+  signal: NodeJS.Signals,
+  timeoutMs: number,
+  name: string,
+): Promise<void> {
+  if (proc.exitCode !== null || proc.signalCode !== null) {
+    return;
+  }
+
+  try {
+    proc.kill(signal);
+  } catch (err) {
+    const errnoErr = err as NodeJS.ErrnoException;
+    if (errnoErr.code !== "ESRCH") {
+      log.warn(`Failed to send ${signal} to ${name}: ${errnoErr.message}`);
+    }
+    return;
+  }
+
+  if (timeoutMs <= 0) return;
+
+  await Promise.race([
+    new Promise<void>((resolve) => proc.once("exit", resolve)),
+    new Promise<void>((resolve) => setTimeout(resolve, timeoutMs)),
+  ]);
+
+  if (proc.exitCode === null && proc.signalCode === null) {
+    if (signal !== "SIGKILL") {
+      log.warn(`${name} did not exit after ${timeoutMs}ms; sending SIGKILL`);
+      try {
+        proc.kill("SIGKILL");
+      } catch {
+        /* ignore */
+      }
+
+      await new Promise<void>((resolve) => setTimeout(resolve, 500));
+
+      if (proc.exitCode === null && proc.signalCode === null) {
+        log.warn(`Process ${name} (pid=${pid}) did not respond to SIGKILL; proceeding anyway`);
+      }
+    } else {
+      log.warn(
+        `Process ${name} (pid=${pid}) did not respond to SIGKILL after ${timeoutMs}ms; proceeding anyway`,
+      );
+    }
+  }
+
+  children.delete(pid);
+}
+
+export function killAllChildrenSync(): void {
+  // Copy entries to avoid mutation during iteration
+  const entries = [...children.entries()];
+  for (const [pid, { name, process: proc }] of entries) {
+    if (proc.exitCode !== null || proc.signalCode !== null) continue;
+    try {
+      // Use console.error since logging may be unreliable during process exit
+      console.error(`[child-registry] Force-killing child process: ${name} (pid=${pid})`);
+      proc.kill("SIGKILL");
+    } catch {
+      /* ignore */
+    }
+  }
+  children.clear();
+}
+
+export function getRegisteredChildren(): Array<{
+  pid: number;
+  name: string;
+  managedExternally: boolean;
+}> {
+  return [...children.entries()].map(([pid, entry]) => ({
+    pid,
+    name: entry.name,
+    managedExternally: entry.managedExternally,
+  }));
+}
+
+export function clearRegistry(): void {
+  children.clear();
+}
diff --git a/src/infra/ssh-tunnel.ts b/src/infra/ssh-tunnel.ts
index 399dc22e3..9cdb6460a 100644
--- a/src/infra/ssh-tunnel.ts
+++ b/src/infra/ssh-tunnel.ts
@@ -1,6 +1,7 @@
 import { spawn } from "node:child_process";
 import net from "node:net";
 
+import { registerChild } from "./child-registry.js";
 import { ensurePortAvailable } from "./ports.js";
 
 export type SshParsedTarget = {
@@ -145,6 +146,8 @@ export async function startSshPortForward(opts: {
   const child = spawn("/usr/bin/ssh", args, {
     stdio: ["ignore", "ignore", "pipe"],
   });
+  // Register with child registry (managedExternally: true because tunnel has its own stop logic)
+  registerChild("ssh-tunnel", child, { managedExternally: true });
   child.stderr?.setEncoding("utf8");
   child.stderr?.on("data", (chunk) => {
     const lines = String(chunk)
diff --git a/src/infra/unhandled-rejections.test.ts b/src/infra/unhandled-rejections.test.ts
index 1ec144ba1..a4f637c5a 100644
--- a/src/infra/unhandled-rejections.test.ts
+++ b/src/infra/unhandled-rejections.test.ts
@@ -127,3 +127,63 @@ describe("isTransientNetworkError", () => {
     expect(isTransientNetworkError(error)).toBe(false);
   });
 });
+
+describe("isTransientNetworkError - expanded patterns", () => {
+  it("recognizes EAI_NODATA as transient", () => {
+    const err = { code: "EAI_NODATA", message: "DNS lookup failed" };
+    expect(isTransientNetworkError(err)).toBe(true);
+  });
+
+  it("recognizes EAI_NONAME as transient", () => {
+    const err = { code: "EAI_NONAME", message: "DNS name not found" };
+    expect(isTransientNetworkError(err)).toBe(true);
+  });
+
+  it("recognizes HTTP 502 as transient", () => {
+    const err = { status: 502, message: "Bad Gateway" };
+    expect(isTransientNetworkError(err)).toBe(true);
+  });
+
+  it("recognizes HTTP 503 as transient", () => {
+    const err = { statusCode: 503, message: "Service Unavailable" };
+    expect(isTransientNetworkError(err)).toBe(true);
+  });
+
+  it("recognizes HTTP 429 rate limit as transient", () => {
+    const err = { status: 429, message: "Too Many Requests" };
+    expect(isTransientNetworkError(err)).toBe(true);
+  });
+
+  it("recognizes socket closed message as transient", () => {
+    const err = new Error("socket closed unexpectedly");
+    expect(isTransientNetworkError(err)).toBe(true);
+  });
+
+  it("recognizes client network socket disconnected as transient", () => {
+    const err = new Error("Client network socket disconnected before secure TLS connection");
+    expect(isTransientNetworkError(err)).toBe(true);
+  });
+
+  it("recognizes TLS certificate errors as transient", () => {
+    const err1 = { code: "CERT_HAS_EXPIRED", message: "certificate has expired" };
+    expect(isTransientNetworkError(err1)).toBe(true);
+
+    const err2 = { code: "ERR_TLS_CERT_ALTNAME_INVALID", message: "Hostname mismatch" };
+    expect(isTransientNetworkError(err2)).toBe(true);
+  });
+
+  it("does not recognize HTTP 400 as transient", () => {
+    const err = { status: 400, message: "Bad Request" };
+    expect(isTransientNetworkError(err)).toBe(false);
+  });
+
+  it("does not recognize HTTP 401 as transient", () => {
+    const err = { status: 401, message: "Unauthorized" };
+    expect(isTransientNetworkError(err)).toBe(false);
+  });
+
+  it("handles string status codes", () => {
+    const err = { status: "503", message: "Service Unavailable" };
+    expect(isTransientNetworkError(err)).toBe(true);
+  });
+});
diff --git a/src/infra/unhandled-rejections.ts b/src/infra/unhandled-rejections.ts
index d186c6a78..3e3041157 100644
--- a/src/infra/unhandled-rejections.ts
+++ b/src/infra/unhandled-rejections.ts
@@ -28,6 +28,10 @@ const TRANSIENT_NETWORK_CODES = new Set([
   "EHOSTUNREACH",
   "ENETUNREACH",
   "EAI_AGAIN",
+  "EAI_NODATA",
+  "EAI_NONAME",
+  "CERT_HAS_EXPIRED",
+  "ERR_TLS_CERT_ALTNAME_INVALID",
   "UND_ERR_CONNECT_TIMEOUT",
   "UND_ERR_DNS_RESOLVE_FAILED",
   "UND_ERR_CONNECT",
@@ -99,6 +103,34 @@ export function isTransientNetworkError(err: unknown): boolean {
     return err.errors.some((e) => isTransientNetworkError(e));
   }
 
+  // Message-based fallback detection
+  const message = err instanceof Error ? err.message?.toLowerCase() : "";
+  if (
+    message.includes("fetch failed") ||
+    message.includes("network error") ||
+    message.includes("socket hang up") ||
+    message.includes("socket closed") ||
+    message.includes("client network socket disconnected")
+  ) {
+    return true;
+  }
+
+  // Check for transient HTTP error responses (handle both number and string status codes)
+  const statusRaw =
+    (err as { status?: unknown }).status ?? (err as { statusCode?: unknown }).statusCode;
+  const status =
+    typeof statusRaw === "number"
+      ? statusRaw
+      : typeof statusRaw === "string"
+        ? parseInt(statusRaw, 10)
+        : NaN;
+  if (
+    Number.isFinite(status) &&
+    (status === 429 || status === 502 || status === 503 || status === 504)
+  ) {
+    return true;
+  }
+
   return false;
 }
 
diff --git a/src/signal/daemon.ts b/src/signal/daemon.ts
index ca1b01b60..ce75b6fbf 100644
--- a/src/signal/daemon.ts
+++ b/src/signal/daemon.ts
@@ -1,5 +1,6 @@
 import { spawn } from "node:child_process";
 import type { RuntimeEnv } from "../runtime.js";
+import { registerChild } from "../infra/child-registry.js";
 
 export type SignalDaemonOpts = {
   cliPath: string;
@@ -52,6 +53,10 @@ export function spawnSignalDaemon(opts: SignalDaemonOpts): SignalDaemonHandle {
   const child = spawn(opts.cliPath, args, {
     stdio: ["ignore", "pipe", "pipe"],
   });
+
+  // Register with child registry (managedExternally: true because signal daemon has its own lifecycle)
+  registerChild("signal-cli-daemon", child, { managedExternally: true });
+
   const log = opts.runtime?.log ?? (() => {});
   const error = opts.runtime?.error ?? (() => {});