diff --git a/src/prerna/reactor/agent/AgentRunner.java b/src/prerna/reactor/agent/AgentRunner.java
index 4c785d2c04..4deb0f983d 100644
--- a/src/prerna/reactor/agent/AgentRunner.java
+++ b/src/prerna/reactor/agent/AgentRunner.java
@@ -278,6 +278,11 @@ private static AgentHarnessResult run(String roomId, String input, String engine
 		AgentConfig agentConfig = AgentConfigLoader.load(room, filePath, modelId, params, agentParams, maxTurns,
 				maxReflections, explicitWorkspaceId);
 
+		// A run that starts an empty room claims it for the agent, as CreateRoom would.
+		if (!resumeMode) {
+			persistWorkspaceOnEmptyRoom(room, insight, explicitWorkspaceId);
+		}
+
 		try {
 			SkillStager.stage(filePath, agentConfig.getSkills());
 		} catch (Exception e) {
@@ -410,6 +415,47 @@ private static final class WorkspaceOverlay {
 		}
 	}
 
+	/**
+	 * Saves {@code workspaceId} on a room that has no messages yet, both as the
+	 * {@code ROOM.WORKSPACE_ID} column and as {@code options.workspace}, so a room
+	 * started by RunAgent matches one created with {@code CreateRoom(workspaceId)}.
+	 * Rooms with messages keep their saved workspace; the run only overlays it.
+	 * Skipped when the workspace is missing, disabled, or not viewable by the
+	 * user.
+	 */
+	static void persistWorkspaceOnEmptyRoom(Room room, Insight insight, String workspaceId) {
+		if (workspaceId == null || workspaceId.trim().isEmpty()) {
+			return;
+		}
+		List<?> messages = room.getMessages();
+		if (messages != null && !messages.isEmpty()) {
+			return;
+		}
+		try {
+			Map<String, Object> ws = ModelInferenceLogsUtils.getWorkspaceEntry(workspaceId);
+			if (ws == null || !Boolean.TRUE.equals(ws.get("is_active")) || insight.getUser() == null
+					|| !SecurityProjectUtils.userCanViewProject(insight.getUser(), workspaceId)) {
+				return;
+			}
+
+			Map<String, Object> workspace = new HashMap<>();
+			workspace.put("workspace_id", workspaceId);
+			if (ws.get("name") != null) {
+				workspace.put("name", String.valueOf(ws.get("name")));
+			}
+			Map<String, Object> opts = new HashMap<>(room.getOptionsMap());
+			opts.put("workspace", workspace);
+
+			ModelInferenceLogsUtils.setRoomWorkspaceId(room.getId(), room.getUserId(), workspaceId);
+			ModelInferenceLogsUtils.setRoomOptions(room.getId(), room.getUserId(), opts);
+			room.setOptionsMap(opts);
+			logger.info("AgentRunner: saved workspace '{}' on empty room '{}'", workspaceId, room.getId());
+		} catch (Exception e) {
+			logger.warn("AgentRunner: could not save workspace '{}' on room '{}': {}", workspaceId, room.getId(),
+					e.getMessage(), e);
+		}
+	}
+
 	/**
 	 * Applies an in-memory workspace override for one run when needed.
 	 */