diff --git a/crates/team-agent/src/lifecycle/tests/harvest2_a_batch_red.rs b/crates/team-agent/src/lifecycle/tests/harvest2_a_batch_red.rs
index 21f7af01..734d47f7 100644
--- a/crates/team-agent/src/lifecycle/tests/harvest2_a_batch_red.rs
+++ b/crates/team-agent/src/lifecycle/tests/harvest2_a_batch_red.rs
@@ -229,7 +229,7 @@ got {status:?}"
 #[test]
 #[serial(t3_event)]
 fn t3_unknown_business_status_is_preserved_without_normalized_event() {
-    let harness = McpSimHarness::new();
+    let harness = McpSimHarness::new_without_tmux();
     let mut worker = harness.spawn_mcp_client("worker_a", "teamA");
     let status = "garbage-status-xyz";
     let call = worker.call_tool(
diff --git a/crates/team-agent/tests/support/mcp_sim_harness.rs b/crates/team-agent/tests/support/mcp_sim_harness.rs
index 65a58b0d..d7e287bf 100644
--- a/crates/team-agent/tests/support/mcp_sim_harness.rs
+++ b/crates/team-agent/tests/support/mcp_sim_harness.rs
@@ -60,27 +60,8 @@ pub struct McpSimHarness {
 
 impl McpSimHarness {
     pub fn new() -> Self {
-        static N: AtomicU64 = AtomicU64::new(0);
-        let run_tag = format!(
-            "{}-{}",
-            std::process::id(),
-            SystemTime::now()
-                .duration_since(UNIX_EPOCH)
-                .expect("system clock after unix epoch")
-                .as_nanos()
-        );
-        let workspace = std::env::temp_dir().join(format!(
-            "ta-rs-mcp-sim-{run_tag}-{}",
-            N.fetch_add(1, Ordering::Relaxed)
-        ));
-        let _ = std::fs::remove_dir_all(&workspace);
-        std::fs::create_dir_all(&workspace).unwrap();
-        let workspace = std::fs::canonicalize(workspace).unwrap();
+        let (workspace, session) = fresh_mcp_workspace();
         let backend = TmuxBackend::for_workspace(&workspace);
-        let session = SessionName::new(format!(
-            "team-mcp-sim-{run_tag}-{}",
-            N.fetch_add(1, Ordering::Relaxed)
-        ));
         let mut harness = Self {
             workspace,
             backend,
@@ -97,6 +78,23 @@ impl McpSimHarness {
         harness
     }
 
+    /// Build an MCP-only fixture for contracts whose assertion does not exercise
+    /// pane delivery. This keeps the stdio ingress test runnable on hosts without
+    /// a tmux binary (for example, the Grok full-test image).
+    pub fn new_without_tmux() -> Self {
+        let (workspace, session) = fresh_mcp_workspace();
+        let backend = TmuxBackend::for_workspace(&workspace);
+        let harness = Self {
+            workspace,
+            backend,
+            session,
+            panes: BTreeMap::new(),
+        };
+        harness.seed_mcp_report_state();
+        let _ = MessageStore::open(&harness.workspace).unwrap();
+        harness
+    }
+
     pub fn spawn_mcp_client(&self, worker_id: &str, owner_team_id: &str) -> McpClient {
         spawn_mcp_client(&self.workspace, worker_id, owner_team_id)
     }
@@ -332,6 +330,47 @@ impl McpSimHarness {
         )
         .unwrap();
     }
+
+    fn seed_mcp_report_state(&self) {
+        team_agent::state::persist::save_runtime_state(
+            &self.workspace,
+            &json!({
+                "active_team_key": "teamA",
+                "teams": {
+                    "teamA": {
+                        "tasks": [
+                            {"id": "task_mcp", "assignee": "worker_a", "status": "pending"}
+                        ]
+                    }
+                }
+            }),
+        )
+        .unwrap();
+    }
+}
+
+fn fresh_mcp_workspace() -> (PathBuf, SessionName) {
+    static N: AtomicU64 = AtomicU64::new(0);
+    let run_tag = format!(
+        "{}-{}",
+        std::process::id(),
+        SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .expect("system clock after unix epoch")
+            .as_nanos()
+    );
+    let workspace = std::env::temp_dir().join(format!(
+        "ta-rs-mcp-sim-{run_tag}-{}",
+        N.fetch_add(1, Ordering::Relaxed)
+    ));
+    let _ = std::fs::remove_dir_all(&workspace);
+    std::fs::create_dir_all(&workspace).unwrap();
+    let workspace = std::fs::canonicalize(workspace).unwrap();
+    let session = SessionName::new(format!(
+        "team-mcp-sim-{run_tag}-{}",
+        N.fetch_add(1, Ordering::Relaxed)
+    ));
+    (workspace, session)
 }
 
 impl Drop for McpSimHarness {