diff --git a/server/src/__tests__/workspace-runtime.test.ts b/server/src/__tests__/workspace-runtime.test.ts
index 9c77635745c..35ca5601c50 100644
--- a/server/src/__tests__/workspace-runtime.test.ts
+++ b/server/src/__tests__/workspace-runtime.test.ts
@@ -1,6 +1,7 @@
 import { execFile } from "node:child_process";
 import { randomUUID } from "node:crypto";
 import fs from "node:fs/promises";
+import net from "node:net";
 import os from "node:os";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
@@ -37,7 +38,7 @@ import {
   stopRuntimeServicesForExecutionWorkspace,
   type RealizedExecutionWorkspace,
 } from "../services/workspace-runtime.ts";
-import { writeLocalServiceRegistryRecord } from "../services/local-service-supervisor.ts";
+import { readLocalServicePortOwner, writeLocalServiceRegistryRecord } from "../services/local-service-supervisor.ts";
 import { resolvePaperclipConfigPath } from "../paths.ts";
 import type { WorkspaceOperation } from "@paperclipai/shared";
 import type { WorkspaceOperationRecorder } from "../services/workspace-operations.ts";
@@ -2915,6 +2916,34 @@ describe("resolveShell (shell fallback)", () => {
   });
 });
 
+describe("readLocalServicePortOwner", () => {
+  it("detects the owner of a listening TCP port", async () => {
+    try {
+      await execFileAsync("lsof", ["-v"]);
+    } catch {
+      return;
+    }
+
+    const server = net.createServer();
+    await new Promise<void>((resolve) => server.listen(0, "127.0.0.1", resolve));
+    try {
+      const address = server.address();
+      const port = typeof address === "object" && address ? address.port : null;
+      expect(port).toBeTypeOf("number");
+
+      const owner = await readLocalServicePortOwner(port!);
+      expect(owner).toBe(process.pid);
+    } finally {
+      await new Promise<void>((resolve, reject) => {
+        server.close((err) => {
+          if (err) reject(err);
+          else resolve();
+        });
+      });
+    }
+  });
+});
+
 describeEmbeddedPostgres("workspace runtime startup reconciliation", () => {
   let db!: ReturnType<typeof createDb>;
   let tempDb: Awaited<ReturnType<typeof startEmbeddedPostgresTestDatabase>> | null = null;
diff --git a/server/src/services/local-service-supervisor.ts b/server/src/services/local-service-supervisor.ts
index 17738e727d7..86d270e37ad 100644
--- a/server/src/services/local-service-supervisor.ts
+++ b/server/src/services/local-service-supervisor.ts
@@ -249,12 +249,17 @@ async function isLikelyMatchingCommand(record: LocalServiceRegistryRecord) {
 
 export async function findAdoptableLocalService(input: {
   serviceKey: string;
+  profileKind?: string | null;
+  serviceName?: string | null;
   command?: string | null;
   cwd?: string | null;
   envFingerprint?: string | null;
   port?: number | null;
+  url?: string | null;
 }) {
-  const record = await readLocalServiceRegistryRecord(input.serviceKey);
+  const record =
+    await readLocalServiceRegistryRecord(input.serviceKey)
+    ?? await adoptLocalServiceFromPortOwner(input);
   if (!record) return null;
 
   if (!isPidAlive(record.pid)) {
@@ -272,6 +277,59 @@ export async function findAdoptableLocalService(input: {
   return record;
 }
 
+async function readProcessGroupId(pid: number) {
+  if (process.platform === "win32") return null;
+  try {
+    const { stdout } = await execFileAsync("ps", ["-o", "pgid=", "-p", String(pid)]);
+    const parsed = Number.parseInt(stdout.trim(), 10);
+    return Number.isInteger(parsed) && parsed > 0 ? parsed : null;
+  } catch {
+    return null;
+  }
+}
+
+async function adoptLocalServiceFromPortOwner(input: {
+  serviceKey: string;
+  profileKind?: string | null;
+  serviceName?: string | null;
+  command?: string | null;
+  cwd?: string | null;
+  envFingerprint?: string | null;
+  port?: number | null;
+  url?: string | null;
+}) {
+  if (!input.port) return null;
+  const ownerPid = await readLocalServicePortOwner(input.port);
+  if (!ownerPid) return null;
+
+  const processGroupId = await readProcessGroupId(ownerPid);
+  const pid = processGroupId && isPidAlive(processGroupId) ? processGroupId : ownerPid;
+  const now = new Date().toISOString();
+  const record: LocalServiceRegistryRecord = {
+    version: 1,
+    serviceKey: input.serviceKey,
+    profileKind: input.profileKind ?? "workspace-runtime",
+    serviceName: input.serviceName ?? "service",
+    command: input.command ?? input.serviceName ?? "service",
+    cwd: input.cwd ?? process.cwd(),
+    envFingerprint: input.envFingerprint ?? "",
+    port: input.port,
+    url: input.url ?? null,
+    pid,
+    processGroupId: processGroupId ?? pid,
+    provider: "local_process",
+    runtimeServiceId: null,
+    reuseKey: input.envFingerprint ?? null,
+    startedAt: now,
+    lastSeenAt: now,
+    metadata: null,
+  };
+
+  if (!(await isLikelyMatchingCommand(record))) return null;
+  await writeLocalServiceRegistryRecord(record);
+  return record;
+}
+
 export async function touchLocalServiceRegistryRecord(
   serviceKey: string,
   patch?: Partial<Omit<LocalServiceRegistryRecord, "serviceKey" | "version">>,
@@ -334,7 +392,7 @@ export async function terminateLocalService(
 export async function readLocalServicePortOwner(port: number) {
   if (!Number.isInteger(port) || port <= 0 || process.platform === "win32") return null;
   try {
-    const { stdout } = await execFileAsync("lsof", ["-nPiTCP", `:${port}`, "-sTCP:LISTEN", "-t"]);
+    const { stdout } = await execFileAsync("lsof", ["-nP", `-iTCP:${port}`, "-sTCP:LISTEN", "-t"]);
     const firstPid = stdout
       .split("\n")
       .map((line) => Number.parseInt(line.trim(), 10))
diff --git a/server/src/services/workspace-runtime.ts b/server/src/services/workspace-runtime.ts
index 5d22c74348c..9681b574250 100644
--- a/server/src/services/workspace-runtime.ts
+++ b/server/src/services/workspace-runtime.ts
@@ -2125,9 +2125,7 @@ async function startLocalRuntimeService(input: {
   });
   const reusableStoppedPort =
     asString(portConfig.type, "") === "auto" && stoppedReuseCandidate?.port
-      ? (await readLocalServicePortOwner(stoppedReuseCandidate.port))
-        ? null
-        : stoppedReuseCandidate.port
+      ? stoppedReuseCandidate.port
       : null;
   const port =
     asString(portConfig.type, "") === "auto"
@@ -2181,10 +2179,13 @@ async function startLocalRuntimeService(input: {
   });
   const adoptedRecord = await findAdoptableLocalService({
     serviceKey,
+    profileKind: "workspace-runtime",
+    serviceName,
     command,
     cwd: serviceCwd,
     envFingerprint: serviceIdentityFingerprint,
-    port: identityPort,
+    port: port ?? identityPort,
+    url,
   });
   if (adoptedRecord) {
     return {