fix(runtime): validate provider process identity

Persist the operating-system start timestamp for the detached Codex provider and require an exact identity match before signaling its PID or process group. Clear stale ownership metadata without killing a replacement process, with focused PID-reuse coverage.

Co-authored-by: Codex <codex@openai.com>

server/src/__tests__/heartbeat-process-recovery.test.ts

@@ -108,6 +108,7 @@ import {
 } from "../services/heartbeat.ts";
 import {
   readHotRestartIntent,
+  readProcessStartedAt,
   resolveLegacyHotRestartIntentPath,
   resolveHotRestartReportPath,
   writeHotRestartIntent,
@@ -490,6 +491,7 @@ describeEmbeddedPostgres("heartbeat orphaned process recovery", () => {
     processGroupId?: number | null;
     providerProcessPid?: number | null;
     providerProcessGroupId?: number | null;
+    providerProcessStartedAt?: Date | null;
     processLossRetryCount?: number;
     includeIssue?: boolean;
     runErrorCode?: string | null;
@@ -552,7 +554,8 @@ describeEmbeddedPostgres("heartbeat orphaned process recovery", () => {
       processGroupId: input?.processGroupId ?? null,
       providerProcessPid: input?.providerProcessPid ?? null,
       providerProcessGroupId: input?.providerProcessGroupId ?? null,
-      providerProcessStartedAt: input?.providerProcessPid ? now : null,
+      providerProcessStartedAt: input?.providerProcessStartedAt
+        ?? (input?.providerProcessPid ? now : null),
       processLossRetryCount: input?.processLossRetryCount ?? 0,
       errorCode: input?.runErrorCode ?? null,
       error: input?.runError ?? null,
@@ -1250,6 +1253,7 @@ describeEmbeddedPostgres("heartbeat orphaned process recovery", () => {
     const { runId } = await seedRunFixture({
       processPid: 999_999_999,
       providerProcessPid: provider.pid ?? null,
+      providerProcessStartedAt: new Date(await readProcessStartedAt(provider.pid ?? 0) ?? 0),
       includeIssue: false,
     });
     const heartbeat = heartbeatService(db);
@@ -1267,6 +1271,32 @@ describeEmbeddedPostgres("heartbeat orphaned process recovery", () => {
     });
   });
 
+  it("does not signal a reused provider pid with a different start time", async () => {
+    const replacement = spawnAliveProcess();
+    childProcesses.add(replacement);
+    expect(replacement.pid).toBeTypeOf("number");
+
+    const { runId } = await seedRunFixture({
+      processPid: 999_999_999,
+      providerProcessPid: replacement.pid ?? null,
+      providerProcessStartedAt: new Date("2020-01-01T00:00:00.000Z"),
+      includeIssue: false,
+    });
+    const heartbeat = heartbeatService(db);
+
+    const result = await heartbeat.reapOrphanedRuns();
+
+    expect(result.reaped).toBe(1);
+    expect(isPidAlive(replacement.pid)).toBe(true);
+    const run = await heartbeat.getRun(runId);
+    expect(run).toMatchObject({
+      status: "failed",
+      providerProcessPid: null,
+      providerProcessGroupId: null,
+      providerProcessStartedAt: null,
+    });
+  });
+
   it("skips generic timer wakes without invoking an adapter when no assigned work is actionable", async () => {
     const { companyId, agentId } = await seedIdleTimerAgentFixture();
     const heartbeat = heartbeatService(db);

server/src/services/heartbeat.ts

@@ -313,6 +313,7 @@ import {
 import {
   findMissingHotRestartSnapshotRunIds,
   readHotRestartIntent,
+  readProcessStartedAt,
   removeHotRestartIntent,
   shouldHonorHotRestartIntentForProcess,
   writeHotRestartReport,
@@ -9941,19 +9942,25 @@ export function heartbeatService(db: Db, options: HeartbeatServiceOptions = {})
   async function terminateRunProviderProcess(
     run: Pick<
       typeof heartbeatRuns.$inferSelect,
-      "id" | "providerProcessPid" | "providerProcessGroupId"
+      "id" | "providerProcessPid" | "providerProcessGroupId" | "providerProcessStartedAt"
     >,
   ): Promise<boolean> {
     const pid = run.providerProcessPid;
     const processGroupId = run.providerProcessGroupId;
     const alive = isProcessAlive(pid) || isProcessGroupAlive(processGroupId);
-    if (alive) {
+    let ownsLiveProcess = false;
+    if (alive && pid && run.providerProcessStartedAt) {
+      const observedStartedAt = await readProcessStartedAt(pid).catch(() => null);
+      ownsLiveProcess = observedStartedAt !== null
+        && Date.parse(observedStartedAt) === run.providerProcessStartedAt.getTime();
+    }
+    if (ownsLiveProcess) {
       await terminateHeartbeatRunProcess({ pid, processGroupId });
     }
     if (pid || processGroupId) {
       await clearRunProviderProcessMetadata(run.id);
     }
-    return alive;
+    return ownsLiveProcess;
   }
 
   async function clearDetachedRunWarning(runId: string) {

server/src/services/native-runtime/native-codex-runner.ts

@@ -10,6 +10,7 @@ import type { AdapterExecutionResult } from "@paperclipai/adapter-utils";
 import type { Db } from "@paperclipai/db";
 
 import { resolvePaperclipInstanceRoot } from "../../home-paths.js";
+import { readProcessStartedAt } from "../hot-restart.js";
 import { runnerPrpCoordinator } from "./runner-prp-coordinator.js";
 
 const moduleDirectory = dirname(fileURLToPath(import.meta.url));
@@ -286,10 +287,14 @@ export async function executeNativeCodexRunner(input: {
         stderr = `${stderr}${chunk}`.slice(-16_384);
       });
       if (!sharedCodexServer.pid) throw new Error("codex_app_server_process_not_started");
+      const providerStartedAt = await readProcessStartedAt(sharedCodexServer.pid);
+      if (!providerStartedAt) {
+        throw new Error("codex_app_server_process_identity_unavailable");
+      }
       await input.onProviderSpawn?.({
         pid: sharedCodexServer.pid,
         processGroupId: process.platform === "win32" ? null : sharedCodexServer.pid,
-        startedAt: new Date().toISOString(),
+        startedAt: providerStartedAt,
       });
       const startupDeadline = Date.now() + 10_000;
       while (