add action history even when empty (#1939)

skyvern/forge/agent.py

@@ -1563,7 +1563,7 @@ class ForgeAgent:
             for action, results in actions_and_results
             if len(results) > 0
         ]
-        return json.dumps(action_history) if action_history else ""
+        return json.dumps(action_history)
 
     async def get_extracted_information_for_task(self, task: Task) -> dict[str, Any] | list | str | None:
         """

skyvern/forge/prompts/skyvern/extract-action.j2

@@ -40,14 +40,12 @@ Reply in JSON format with the following keys:
     "verification_code_reasoning": str, // Let's think step by step. Describe what you see and think if a verification code is needed for login or any verification step. Explain why you believe a verification code is needed or not. Has the code been sent and is code available somewhere (email, phone or 2FA device)?
     "need_verification_code": bool, // Whether a verification code must be entered on this page now. True only if the code is available to user. If the code is not sent, return false {% endif %}
 }
-{% if action_history %}
-Consider the action history from the last step and the screenshot together, if actions from the last step don't yield positive impact, try other actions or other action combinations.
 
+Consider the action history from the last step and the screenshot together, if actions from the last step don't yield positive impact, try other actions or other action combinations.
 Action history from previous steps: (note: even if the action history suggests goal is achieved, check the screenshot and the DOM elements to make sure the goal is achieved)
 ```
 {{ action_history }}
 ```
-{% endif %}
 {% if complete_criterion %}
 Complete criterion:
 ```

skyvern/webeye/actions/caching.py

@@ -229,6 +229,7 @@ async def personalize_action(
         ActionType.COMPLETE,
         ActionType.WAIT,
         ActionType.SOLVE_CAPTCHA,
+        ActionType.NULL_ACTION,
     ]:
         return [action]
     elif action.action_type == ActionType.TERMINATE: