diff --git a/packages/adapters/grok-local/src/server/execute.test.ts b/packages/adapters/grok-local/src/server/execute.test.ts
index 3d7f5d6c9b..2b03c7dcbd 100644
--- a/packages/adapters/grok-local/src/server/execute.test.ts
+++ b/packages/adapters/grok-local/src/server/execute.test.ts
@@ -139,8 +139,6 @@ describe("grok_local execute", () => {
   });
 
   it("reports real per-run token usage, marks it as per_run, and only surfaces cost for API billing", async () => {
-    const root = await makeTempRoot();
-
     runProcessMock.mockImplementation(async () => ({
       exitCode: 0,
       signal: null,
@@ -159,8 +157,8 @@ describe("grok_local execute", () => {
       stderr: "",
     }));
 
-    const baseCtx: AdapterExecutionContext = {
-      runId: "run-1",
+    const makeCtx = async (runId: string): Promise<AdapterExecutionContext> => ({
+      runId,
       agent: {
         id: "agent-1",
         companyId: "company-1",
@@ -169,27 +167,30 @@ describe("grok_local execute", () => {
         adapterConfig: {},
       },
       runtime: { sessionId: null, sessionParams: null, sessionDisplayId: null, taskKey: null },
-      config: { cwd: root },
+      config: { cwd: await makeTempRoot() },
       context: {},
       authToken: "run-token",
       onLog: async () => {},
-    };
-
-    // Subscription billing (no XAI_API_KEY): token usage is populated, but
-    // there is no marginal dollar cost so costUsd stays null.
-    const subscriptionResult = await execute(baseCtx);
-    expect(subscriptionResult).toMatchObject({
-      usage: { inputTokens: 2384, outputTokens: 261, cachedInputTokens: 23040 },
-      usageBasis: "per_run",
-      billingType: "subscription",
-      costUsd: null,
     });
 
-    // API-key billing: same token usage, plus the real dollar cost.
     const previousApiKey = process.env.XAI_API_KEY;
-    process.env.XAI_API_KEY = "test-key";
     try {
-      const apiResult = await execute(baseCtx);
+      // Subscription billing (no XAI_API_KEY): token usage is populated, but
+      // there is no marginal dollar cost so costUsd stays null. Clear the key
+      // explicitly so the ambient environment (dev machine or CI with provider
+      // secrets) cannot flip this branch to API billing.
+      delete process.env.XAI_API_KEY;
+      const subscriptionResult = await execute(await makeCtx("run-subscription"));
+      expect(subscriptionResult).toMatchObject({
+        usage: { inputTokens: 2384, outputTokens: 261, cachedInputTokens: 23040 },
+        usageBasis: "per_run",
+        billingType: "subscription",
+        costUsd: null,
+      });
+
+      // API-key billing: same token usage, plus the real dollar cost.
+      process.env.XAI_API_KEY = "test-key";
+      const apiResult = await execute(await makeCtx("run-api"));
       expect(apiResult).toMatchObject({
         usage: { inputTokens: 2384, outputTokens: 261, cachedInputTokens: 23040 },
         usageBasis: "per_run",