diff --git a/src/tui/index.ts b/src/tui/index.ts
index 61d6fdca..8ca4c8a4 100644
--- a/src/tui/index.ts
+++ b/src/tui/index.ts
@@ -257,12 +257,13 @@ async function isHealthy(origin: string): Promise<boolean> {
 }
 
 /**
- * Origins this project's running servers have published, confirmed healthy.
+ * Origins this process published for the project, confirmed healthy.
+ *
+ * Worker threads share process.pid; an attached TUI needs the instance-scoped scrape.
  *
  * A record is only a hint about where to look: `/health` decides whether
  * anything is actually serving there. That also covers a server that died
- * without cleaning up (its record is pruned by the reader) and an unrelated
- * service squatting the port.
+ * without cleaning up and an unrelated service squatting the port.
  */
 async function healthyRuntimeOrigins(api: TuiPluginApi): Promise<string[]> {
   let directory: string | undefined
@@ -275,6 +276,7 @@ async function healthyRuntimeOrigins(api: TuiPluginApi): Promise<string[]> {
   }
   const healthy: string[] = []
   for (const record of originsForProject(directory, worktree)) {
+    if (record.pid !== process.pid) continue
     for (const origin of candidateOrigins(record)) {
       if (await isHealthy(origin)) {
         healthy.push(origin)
@@ -359,8 +361,8 @@ async function bootstrapOrigin(api: TuiPluginApi): Promise<string | null> {
  * Resolve the PTY server origin, cheapest and quietest first:
  *
  *  1. cached, while it still answers
- *  2. an origin record this project published, confirmed by `/health` — the
- *     common case, and it costs no session
+ *  2. an origin record this process published for this project, confirmed by
+ *     `/health` — the same-process case, and it costs no session
  *  3. the instance-scoped scrape through a throwaway session — when nothing is
  *     advertised (starting one, if asked) or when several records match and only
  *     the caller's own opencode server can say which is ours
diff --git a/test/tui-index.test.ts b/test/tui-index.test.ts
index 11af0d5e..e6939e5e 100644
--- a/test/tui-index.test.ts
+++ b/test/tui-index.test.ts
@@ -16,8 +16,8 @@
 // effects, not rendering.
 // =============================================================================
 
-import { afterEach, beforeEach, describe, expect, mock, test } from 'bun:test'
-import { mkdtempSync, rmSync } from 'node:fs'
+import { afterEach, beforeEach, describe, expect, jest, mock, test } from 'bun:test'
+import { mkdtempSync, rmSync, writeFileSync } from 'node:fs'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { writeOrigin } from '../src/shared/runtime.ts'
@@ -276,6 +276,46 @@ describe('pty sidebar tui factory', () => {
     }
   })
 
+  test('does not adopt a healthy origin published by another process for the same project', async () => {
+    let sessionRequests = 0
+    const listener = Bun.serve({
+      hostname: '::1',
+      port: 0,
+      fetch: (req) => {
+        if (new URL(req.url).pathname === '/api/sessions') {
+          sessionRequests++
+          return Response.json([])
+        }
+        return Response.json({ status: 'healthy', sessions: { total: 0, active: 0 } })
+      },
+    })
+    writeFileSync(
+      join(runtimeDir, 'foreign.json'),
+      JSON.stringify({
+        pid: process.pid + 1,
+        hostname: '::1',
+        port: listener.port,
+        directory: PROJECT,
+      })
+    )
+    const realFetch = globalThis.fetch
+    const { api, sidebar, disposeNow } = stubApi()
+    jest.useFakeTimers()
+    try {
+      // Dispatch in-process so discovery settles on microtasks, not network timing.
+      globalThis.fetch = (async (input) => listener.fetch(String(input))) as typeof fetch
+      await plugin.tui(api as never)
+      while (textNodesOf(sidebar()).includes('▶ PTY  starting…')) await Promise.resolve()
+      expect(sessionRequests).toBe(0)
+      expect(textNodesOf(sidebar())).toContain('▶ PTY  not running — click to start')
+    } finally {
+      globalThis.fetch = realFetch
+      listener.stop(true)
+      disposeNow()
+      jest.useRealTimers()
+    }
+  })
+
   test('defers a start asked for while a refresh is in flight', async () => {
     // Hold the load refresh open so the ask lands while one is provably in
     // flight. The overlap guard must DEFER an explicit ask, never drop it — the