diff --git a/src/lib/onboard/machine/flow-slices.test.ts b/src/lib/onboard/machine/flow-slices.test.ts
index 5afd843e4a..3810c34342 100644
--- a/src/lib/onboard/machine/flow-slices.test.ts
+++ b/src/lib/onboard/machine/flow-slices.test.ts
@@ -12,10 +12,15 @@ import {
   type SessionUpdates,
 } from "../../state/onboard-session";
 import type { OnboardFlowContext } from "./flow-context";
-import { advanceTo } from "./result";
+import { advanceTo, branchTo } from "./result";
 import { OnboardRuntime, type OnboardRuntimeDeps } from "./runtime";
 import type { OnboardSequencePhase } from "./sequence-runner";
-import { initialOnboardFlowPhases, runInitialOnboardFlowSequence } from "./flow-slices";
+import {
+  coreOnboardFlowPhases,
+  initialOnboardFlowPhases,
+  runCoreOnboardFlowSequence,
+  runInitialOnboardFlowSequence,
+} from "./flow-slices";
 
 function cloneSession(session: Session): Session {
   return normalizeSession(JSON.parse(JSON.stringify(session))) ?? session;
@@ -132,4 +137,47 @@ describe("onboard flow slices", () => {
 
     expect(result.session.machine.state).toBe("provider_selection");
   });
+
+  it("selects only core provider/sandbox phases", () => {
+    expect(
+      coreOnboardFlowPhases([
+        phase("gateway", "provider_selection"),
+        phase("provider_selection", "sandbox"),
+        phase("sandbox", "openclaw"),
+        phase("openclaw", "policies"),
+      ]).map((entry) => entry.state),
+    ).toEqual(["provider_selection", "sandbox"]);
+  });
+
+  it("runs the core slice and stops at the selected branch state", async () => {
+    const result = await runCoreOnboardFlowSequence({
+      context: context(),
+      runtime: runtime(
+        createSession({
+          machine: {
+            version: MACHINE_SNAPSHOT_VERSION,
+            state: "provider_selection",
+            stateEnteredAt: "2026-05-29T00:00:00.000Z",
+            revision: 0,
+          },
+        }),
+      ),
+      phases: [
+        {
+          state: "provider_selection",
+          run: (ctx) => ({
+            context: ctx,
+            result: [
+              advanceTo("inference", { metadata: { state: "provider_selection" } }),
+              advanceTo("sandbox", { metadata: { state: "inference" } }),
+            ],
+          }),
+        },
+        { state: "sandbox", run: (ctx) => ({ context: ctx, result: branchTo("openclaw") }) },
+        phase("openclaw", "policies"),
+      ],
+    });
+
+    expect(result.session.machine.state).toBe("openclaw");
+  });
 });
diff --git a/src/lib/onboard/machine/flow-slices.ts b/src/lib/onboard/machine/flow-slices.ts
index bf88e7e75b..cefa3b8bff 100644
--- a/src/lib/onboard/machine/flow-slices.ts
+++ b/src/lib/onboard/machine/flow-slices.ts
@@ -20,6 +20,14 @@ export function initialOnboardFlowPhases<Context extends OnboardFlowContext>(
   ];
 }
 
+export function coreOnboardFlowPhases<Context extends OnboardFlowContext>(
+  phases: readonly OnboardSequencePhase<Context>[],
+): OnboardSequencePhase<Context>[] {
+  return phases.filter(
+    (phase) => phase.state === "provider_selection" || phase.state === "sandbox",
+  );
+}
+
 export async function runInitialOnboardFlowSequence<Context extends OnboardFlowContext>(options: {
   context: Context;
   runtime: OnboardMachineRunnerRuntime;
@@ -31,3 +39,15 @@ export async function runInitialOnboardFlowSequence<Context extends OnboardFlowC
     stopStates: ["provider_selection"],
   });
 }
+
+export async function runCoreOnboardFlowSequence<Context extends OnboardFlowContext>(options: {
+  context: Context;
+  runtime: OnboardMachineRunnerRuntime;
+  phases: readonly OnboardSequencePhase<Context>[];
+}) {
+  return runOnboardSequenceWithRunner({
+    ...options,
+    phases: coreOnboardFlowPhases(options.phases),
+    stopStates: ["openclaw", "agent_setup"],
+  });
+}
diff --git a/test/sandbox-connect-inference/auto-pair-approval.test.ts b/test/sandbox-connect-inference/auto-pair-approval.test.ts
index 770d8befb6..653756acf9 100644
--- a/test/sandbox-connect-inference/auto-pair-approval.test.ts
+++ b/test/sandbox-connect-inference/auto-pair-approval.test.ts
@@ -292,12 +292,9 @@ describe("sandbox connect scope-upgrade approval on recover/probe (#4504)", () =
         "claude-sonnet-4-20250514",
       );
 
-      const result = runConnect(
-        tmpDir,
-        sandboxName,
-        { NEMOCLAW_TEST_FAIL_APPROVAL_PASS: "1" },
-        ["--probe-only"],
-      );
+      const result = runConnect(tmpDir, sandboxName, { NEMOCLAW_TEST_FAIL_APPROVAL_PASS: "1" }, [
+        "--probe-only",
+      ]);
       expect(result.status).toBe(0);
 
       const state = JSON.parse(fs.readFileSync(stateFile, "utf-8"));
@@ -326,12 +323,9 @@ describe("sandbox connect scope-upgrade approval on recover/probe (#4504)", () =
         "claude-sonnet-4-20250514",
       );
 
-      const result = runConnect(
-        tmpDir,
-        sandboxName,
-        { NEMOCLAW_TEST_GATEWAY_DOWN: "1" },
-        ["--probe-only"],
-      );
+      const result = runConnect(tmpDir, sandboxName, { NEMOCLAW_TEST_GATEWAY_DOWN: "1" }, [
+        "--probe-only",
+      ]);
       expect(result.status).toBe(1);
 
       const state = JSON.parse(fs.readFileSync(stateFile, "utf-8"));