Update README.md

update action space

README.md

@@ -223,6 +223,25 @@ response = predict(instruction, image)
 print(response)
 ```
 
+### Action Space
+
+At each step, the agent outputs is a single JSON object that contains:
+- One (and only one) primitive action, chosen from the list below;
+- Optional modifiers (`duration`, `thought`) and/or a task-level flag (`STATUS`).
+
+Note that all keywords are **case-sensitive**, and we use **compact JSON** (i.e., no extra whitespace), which affects the tokenizer’s behavior.
+
+| Action         | Required field(s)                                                                                           | Optional field(s)             | Purpose                                                                     |  Example                                  |
+| --------------------- | ----------------------------------------------------------------------------------------------------------- | ----------------------------- | --------------------------------------------------------------------------- | ------------------------------------------------ |
+| **Click**               | `POINT:[x,y]`                                                                                               | `duration`,`thought`,`STATUS` | Single tap at the normalized screen coordinate (0–1000, origin = top-left). | `{"POINT":[480,320]}`                            |
+| **Long Press**               | `POINT:[x,y]`<br>`duration:1000`                                                                                               | `duration`,`thought`,`STATUS` | Touch-and-hold at coordinate (set a longer duration, e.g. >200 ms). | `{"POINT":[480,320],"duration":1000}`                            |
+| **Swipe**      | `POINT:[x,y]`<br>`to:"up" \| "down" \| "left" \| "right"` **or** `to:[x,y]`                                 | `duration`,`thought`,`STATUS` | Swipe from the start point toward a direction **or** another coordinate.     | `{"POINT":[500,200],"to":"down"}` |
+| **Press key**         | `PRESS:"HOME" \| "BACK" \| "ENTER"`                                                                         | `duration`,`thought`,`STATUS` | Trigger a hardware / navigation button.                                     | `{"PRESS":"HOME"}`                |
+| **Type text**         | `TYPE:"<text>"`                                                                    | `duration`,`thought`,`STATUS` | Insert the given text at the current input focus.                           | `{"TYPE":"Hello, world!"}`                       |
+| **Wait**              | `duration`                                                                              | `thought`,`STATUS`            | Idle for the specified time without any other action.                       | `{"duration":500}`                               |
+| **Task-level status** | `STATUS:"start" \| "continue" \| "finish" \| "satisfied" \| "impossible" \| "interrupt" \| "need_feedback"` | `duration`,`thought`          | Report task progress; may appear **alone** or **with a primitive action**.  | `{"STATUS":"finish"}`                        |
+
+
 ## Fine-tuning
 
 Source code for SFT and RFT training is provided — see [GitHub](https://github.com/OpenBMB/AgentCPM-GUI).