diff --git a/cloud/apps/push/src/push-delivery-message.ts b/cloud/apps/push/src/push-delivery-message.ts
index 3bd2dae6e7c..1d37f621573 100644
--- a/cloud/apps/push/src/push-delivery-message.ts
+++ b/cloud/apps/push/src/push-delivery-message.ts
@@ -6,6 +6,7 @@ export type PushOrcaData = {
   hostFingerprint: string
   worktreeId?: string
   paneKey?: string
+  executionHost?: string
   notificationId?: string
   notificationSeq: number
   notificationEpoch: string
@@ -54,6 +55,9 @@ export function buildPushDelivery(input: {
       hostFingerprint,
       ...(notification.paneKey === undefined ? {} : { paneKey: notification.paneKey }),
       ...(notification.worktreeId === undefined ? {} : { worktreeId: notification.worktreeId }),
+      ...(notification.executionHost === undefined
+        ? {}
+        : { executionHost: notification.executionHost }),
       ...(notification.notificationId === undefined
         ? {}
         : { notificationId: notification.notificationId }),
diff --git a/cloud/apps/push/src/push-execution-host-routing.test.ts b/cloud/apps/push/src/push-execution-host-routing.test.ts
new file mode 100644
index 00000000000..fcc688e6bcc
--- /dev/null
+++ b/cloud/apps/push/src/push-execution-host-routing.test.ts
@@ -0,0 +1,35 @@
+import { expect, it } from 'vitest'
+import { PushNotificationSchema } from '@orca-cloud/push-contract'
+import { buildPushDelivery, orcaDataStrings } from './push-delivery-message.js'
+
+const base = {
+  notificationSeq: 1,
+  notificationEpoch: 'epoch',
+  source: 'agent-task-complete',
+  agentState: 'finished',
+  title: 'Done',
+  body: '',
+  worktreeId: 'repo-1::/srv/work'
+}
+
+it('carries the workspace server to APNs and FCM, and accepts older messages without one', () => {
+  const executionHost = 'runtime:env%201'
+  for (const extra of [{}, { executionHost }]) {
+    const delivery = buildPushDelivery({
+      notification: PushNotificationSchema.parse({ ...base, ...extra }),
+      hostFingerprint: 'host',
+      registrationId: 'phone',
+      expiresAt: Date.now() + 300000
+    })
+    const expected = 'executionHost' in extra ? executionHost : undefined
+    expect(delivery.orca.executionHost).toBe(expected)
+    expect(orcaDataStrings(delivery.orca).executionHost).toBe(expected)
+  }
+})
+
+it('accepts only runtime execution hosts', () => {
+  const invalid = ['local', 'ssh:box', 'runtime:', 'runtime:a|b', `runtime:${'x'.repeat(2048)}`]
+  for (const executionHost of invalid) {
+    expect(PushNotificationSchema.safeParse({ ...base, executionHost }).success).toBe(false)
+  }
+})
diff --git a/cloud/packages/push-contract/src/send-messages.ts b/cloud/packages/push-contract/src/send-messages.ts
index a8959c18b05..61e4c1b9166 100644
--- a/cloud/packages/push-contract/src/send-messages.ts
+++ b/cloud/packages/push-contract/src/send-messages.ts
@@ -27,7 +27,13 @@ export const PushNotificationSchema = z
     title: z.string().min(1).max(PUSH_LIMITS.titleMaxChars),
     body: z.string().max(PUSH_LIMITS.bodyMaxChars),
     worktreeId: z.string().min(1).max(2048).optional(),
-    paneKey: z.string().min(1).max(2048).optional()
+    paneKey: z.string().min(1).max(2048).optional(),
+    // The workspace's server; mirrors the app's runtime host id (cannot import src/shared).
+    executionHost: z
+      .string()
+      .max(2048)
+      .regex(/^runtime:[^|\s]+$/)
+      .optional()
   })
   .strict()
   .refine(