diff --git a/packages/cli/src/services/server-connection.ts b/packages/cli/src/services/server-connection.ts
index 4eccc95bc94f..666f113034a7 100644
--- a/packages/cli/src/services/server-connection.ts
+++ b/packages/cli/src/services/server-connection.ts
@@ -49,10 +49,12 @@ export const resolve = Effect.fn("cli.server-connection.resolve")(function* (arg
   } satisfies Resolved
 })
 
+/** Passive reconnect: ensure-running with no version replacement authority. */
+export const managedReconnect = (options: EnsureOptions) => Service.ensure({ ...options, version: undefined })
+
 function managedService(options: EnsureOptions) {
-  const reconnectOptions = { ...options, version: undefined }
   return {
-    reconnect: () => Service.ensure(reconnectOptions),
+    reconnect: () => managedReconnect(options),
     restart: () =>
       Effect.gen(function* () {
         yield* Service.stop(options)
diff --git a/packages/cli/test/server-connection.test.ts b/packages/cli/test/server-connection.test.ts
index 41a061f57c03..b72ffae5c707 100644
--- a/packages/cli/test/server-connection.test.ts
+++ b/packages/cli/test/server-connection.test.ts
@@ -1,14 +1,65 @@
 import { NodeFileSystem } from "@effect/platform-node"
+import type { EnsureReason } from "@opencode-ai/client/effect/service"
 import { Global } from "@opencode-ai/core/global"
 import { InstallationVersion } from "@opencode-ai/core/installation/version"
 import { expect, test } from "bun:test"
-import { Effect, FileSystem, Scope } from "effect"
+import { Effect, Exit, FileSystem, Scope } from "effect"
 import fs from "node:fs/promises"
 import os from "node:os"
 import path from "node:path"
 import { ServerConnection } from "../src/services/server-connection"
 import { ServiceConfig } from "../src/services/service-config"
 
+const runReconnect = <A, E>(effect: Effect.Effect<A, E, FileSystem.FileSystem>) =>
+  Effect.runPromise(effect.pipe(Effect.provide(NodeFileSystem.layer)))
+
+test("managed reconnect ensures the service on the first failure", async () => {
+  const root = await fs.mkdtemp(path.join(os.tmpdir(), "opencode-service-reconnect-"))
+  const starts: EnsureReason[] = []
+  try {
+    // Short-circuit ensure once it decides to spawn — we only need the reason.
+    const exit = await runReconnect(
+      ServerConnection.managedReconnect({
+        file: path.join(root, "service.json"),
+        onStart: (reason) => {
+          starts.push(reason)
+          throw new Error("service ensure invoked")
+        },
+      }).pipe(Effect.exit),
+    )
+    expect(Exit.isFailure(exit)).toBe(true)
+    expect(starts).toEqual(["missing"])
+  } finally {
+    await fs.rm(root, { recursive: true, force: true })
+  }
+})
+
+test("managed reconnect reuses a healthy service from another version", async () => {
+  const root = await fs.mkdtemp(path.join(os.tmpdir(), "opencode-service-reconnect-version-"))
+  const server = Bun.serve({
+    port: 0,
+    fetch() {
+      return Response.json({ healthy: true, version: "older", pid: process.pid })
+    },
+  })
+  const file = path.join(root, "service.json")
+  const url = server.url.toString()
+  await Bun.write(file, JSON.stringify({ url, pid: process.pid, version: "older" }))
+  try {
+    const endpoint = await runReconnect(
+      ServerConnection.managedReconnect({
+        file,
+        version: "newer",
+        command: [path.join(root, "must-not-start")],
+      }),
+    )
+    expect(endpoint.url).toBe(url)
+  } finally {
+    await server.stop(true)
+    await fs.rm(root, { recursive: true, force: true })
+  }
+})
+
 test("resolution groups Effect-native lifecycle operations only for the managed service", async () => {
   const root = await fs.mkdtemp(path.join(os.tmpdir(), "opencode-server-resolution-"))
   const id = "server-resolution-test"