diff --git a/src/local-model/install-job.ts b/src/local-model/install-job.ts
index 44098e9b..b518836a 100644
--- a/src/local-model/install-job.ts
+++ b/src/local-model/install-job.ts
@@ -84,6 +84,7 @@ import type {
   LocalModelConflict,
   LocalModelDeveloperTools,
   LocalModelErrorCode,
+  LocalModelInstallError,
   LocalModelInstallRequest,
   LocalModelInstallState,
   LocalModelInstallStep,
@@ -458,6 +459,16 @@ export interface LocalModelServiceDeps {
 export interface LocalModelService {
   /** The `install` object of the GET. Never throws. */
   view(): Promise<LocalModelInstallView>;
+  /**
+   * Whether a session may be started on the saved endpoint `endpointId` right now. `undefined`:
+   * yes, which is also the answer for every endpoint that is not this feature's. Otherwise the
+   * error that refuses the launch, in this order: `runtime-not-running` (the runtime child
+   * Codeman started is not alive, so whatever answers on the port is not ours),
+   * `port-in-use`, `runtime-stopped`, `model-changed` (the digest is read again and is not the
+   * stored one). The session launch path asks this before it starts a session with the
+   * managed endpoint, and `boot()` asks it once. Never throws.
+   */
+  launchRefusal(endpointId: string): Promise<LocalModelInstallError | undefined>;
   /** What the GET passes to `recommend()`: the stored measured total and the runtime download that is still needed. */
   recommendOptions(): Promise<RecommendOptions>;
   /** `POST /api/local-model/install`. Answers once the job is STARTED; the job runs on in the server. */
diff --git a/src/types/local-model-install.ts b/src/types/local-model-install.ts
index 5d625d7a..d964e53a 100644
--- a/src/types/local-model-install.ts
+++ b/src/types/local-model-install.ts
@@ -116,6 +116,8 @@ export const LOCAL_MODEL_INSTALL_STEPS: readonly LocalModelInstallStep[] = [
  * | `runtime-unpack-failed`   | `/usr/bin/tar` failed                                                    |
  * | `runtime-start-failed`    | the runtime was started and never answered `/api/version`                |
  * | `runtime-stopped`         | installed: the runtime crashed and was restarted 3 times, then given up  |
+ * | `runtime-not-running`     | installed: the runtime is not running (the person stopped it). Only a    |
+ * |                           | refused session start says it; the view shows no error for a stopped runtime |
  * | `port-in-use`             | another program listens on the stored port, or no port of the span is free |
  * | `disk-full`               | a write failed for lack of space                                         |
  * | `pull-failed`             | the pull still ends on an error line or a cut stream after its retries   |
@@ -137,6 +139,7 @@ export type LocalModelErrorCode =
   | 'runtime-unpack-failed'
   | 'runtime-start-failed'
   | 'runtime-stopped'
+  | 'runtime-not-running'
   | 'port-in-use'
   | 'disk-full'
   | 'pull-failed'
@@ -218,6 +221,7 @@ export const LOCAL_MODEL_INSTALL_LABELS = {
   errRuntimeUnpackFailed: 'The runtime could not be unpacked on this Mac.',
   errRuntimeStartFailed: 'The runtime did not start on this Mac.',
   errRuntimeStopped: 'The runtime keeps stopping, so Codeman no longer restarts it.',
+  errRuntimeNotRunning: 'The model on this Mac is not running. Start it first.',
   errPortInUse: 'Port {port} is in use by another program.',
   errDiskFull: 'The disk is full. Free up space, then try again.',
   errPullFailed: 'The download keeps stopping. The network may be damaging data. Try again or use another network.',
@@ -259,6 +263,7 @@ export const LOCAL_MODEL_ERROR_LABELS: Record<LocalModelErrorCode, LocalModelIns
   'runtime-unpack-failed': LOCAL_MODEL_INSTALL_LABELS.errRuntimeUnpackFailed,
   'runtime-start-failed': LOCAL_MODEL_INSTALL_LABELS.errRuntimeStartFailed,
   'runtime-stopped': LOCAL_MODEL_INSTALL_LABELS.errRuntimeStopped,
+  'runtime-not-running': LOCAL_MODEL_INSTALL_LABELS.errRuntimeNotRunning,
   'port-in-use': LOCAL_MODEL_INSTALL_LABELS.errPortInUse,
   'disk-full': LOCAL_MODEL_INSTALL_LABELS.errDiskFull,
   'pull-failed': LOCAL_MODEL_INSTALL_LABELS.errPullFailed,
@@ -282,6 +287,7 @@ export const LOCAL_MODEL_ERROR_NEXT: Record<LocalModelErrorCode, LocalModelNextS
   'runtime-unpack-failed': 'retry',
   'runtime-start-failed': 'retry',
   'runtime-stopped': 'start',
+  'runtime-not-running': 'start',
   'port-in-use': 'other-port',
   'disk-full': 'retry',
   'pull-failed': 'retry',
diff --git a/test/fixtures/fake-ollama.ts b/test/fixtures/fake-ollama.ts
index fa680ea7..3b889027 100644
--- a/test/fixtures/fake-ollama.ts
+++ b/test/fixtures/fake-ollama.ts
@@ -67,12 +67,12 @@ export const REAL_INFERENCE_COMPUTE_LINE_MAC_MINI =
   'time=2026-11-06T13:21:49.885+01:00 level=INFO source=types.go:32 msg="inference compute" id=0 filter_id=0 library=Metal compute=0.0 name=MTL0 description="Apple M4" libdirs="" driver=0.0 pci_id="" type=iGPU total="11.8 GiB" available="11.8 GiB"';
 
 /**
- * The same line as the 48 GB MacBook (Apple M5 Pro) printed it on 2026-11-06. The measurement
- * notes quote `total="37.4 GiB" available="37.4 GiB"`; the rest of the line is the Mac mini's
- * with the chip name and a time filled in. `parseInferenceComputeTotal()` must read
- * 40,157,944,217 bytes from it.
+ * The same line for the 48 GB MacBook (Apple M5 Pro), RECONSTRUCTED: the measurement notes of
+ * 2026-11-06 quote only `total="37.4 GiB" available="37.4 GiB"` from it, so the rest is the
+ * Mac mini's line with the chip name and a time filled in (hence no `REAL_` in the name).
+ * `parseInferenceComputeTotal()` must read 40,157,944,217 bytes from it.
  */
-export const REAL_INFERENCE_COMPUTE_LINE_MACBOOK =
+export const INFERENCE_COMPUTE_LINE_MACBOOK =
   'time=2026-11-06T15:04:12.371+01:00 level=INFO source=types.go:32 msg="inference compute" id=0 filter_id=0 library=Metal compute=0.0 name=MTL0 description="Apple M5 Pro" libdirs="" driver=0.0 pci_id="" type=iGPU total="37.4 GiB" available="37.4 GiB"';
 
 /** 37.4 GiB in bytes, rounded down: what the MacBook line stands for. */
diff --git a/test/local-model-fake-ollama.test.ts b/test/local-model-fake-ollama.test.ts
index 35440acd..ccd207de 100644
--- a/test/local-model-fake-ollama.test.ts
+++ b/test/local-model-fake-ollama.test.ts
@@ -23,9 +23,9 @@ import {
   fakeRuntimeLog,
   FakeRuntimeChild,
   freeLoopbackPort,
+  INFERENCE_COMPUTE_LINE_MACBOOK,
   MACBOOK_MEASURED_TOTAL_BYTES,
   REAL_INFERENCE_COMPUTE_LINE_MAC_MINI,
-  REAL_INFERENCE_COMPUTE_LINE_MACBOOK,
   REAL_PULL_ERROR_LINE,
   startFakeOllama,
   type FakeOllama,
@@ -364,7 +364,7 @@ describe('the fake runtime: the archive', () => {
 describe('the fake runtime: the child process', () => {
   it('holds the real log lines with the device total', () => {
     expect(REAL_INFERENCE_COMPUTE_LINE_MAC_MINI).toContain('total="11.8 GiB" available="11.8 GiB"');
-    expect(REAL_INFERENCE_COMPUTE_LINE_MACBOOK).toContain('total="37.4 GiB" available="37.4 GiB"');
+    expect(INFERENCE_COMPUTE_LINE_MACBOOK).toContain('total="37.4 GiB" available="37.4 GiB"');
     expect(MACBOOK_MEASURED_TOTAL_BYTES).toBe(Math.floor(37.4 * 1024 ** 3));
     expect(fakeRuntimeLog('37.4 GiB')[2]).toContain('msg="inference compute"');
   });