Update filter.mdx

docs/features/plugin/functions/filter.mdx

@@ -23,7 +23,8 @@ Filters sit in the middle of the flow—like checkpoints—where you decide what
 Here’s a quick summary of what Filters do:
 
 1. **Modify User Inputs (Inlet Function)**: Tweak the input data before it reaches the AI model. This is where you enhance clarity, add context, sanitize text, or reformat messages to match specific requirements.
-2. **Modify Model Outputs (Outlet Function)**: Adjust the AI's response **after it’s processed**, before showing it to the user. This can help refine, log, or adapt the data for a cleaner user experience.
+2. **Intercept Model Outputs (Stream Function)**: Capture and adjust the AI’s responses **as they’re generated** by the model. This is useful for real-time modifications, like filtering out sensitive information or formatting the output for better readability.
+3. **Modify Model Outputs (Outlet Function)**: Adjust the AI's response **after it’s processed**, before showing it to the user. This can help refine, log, or adapt the data for a cleaner user experience.
 
 > **Key Concept:** Filters are not standalone models but tools that enhance or transform the data traveling *to* and *from* models.  
 
@@ -55,6 +56,11 @@ class Filter:
         print(f"inlet called: {body}")
         return body  
 
+    def stream(self, event: dict) -> dict:
+        # This is where you modify streamed chunks of model output.
+        print(f"stream event: {event}")
+        return event
+
     def outlet(self, body: dict) -> None:
         # This is where you manipulate model outputs.
         print(f"outlet called: {body}")
@@ -149,7 +155,52 @@ Note: The user feels the same, but the model processes a cleaner and easier-to-u
 
 ---
 
-#### 3️⃣ **`outlet` Function (Output Post-Processing)**
+## 🆕 3️⃣ **`stream` Hook (New in Open WebUI 0.5.17)**
+
+### 🔄 What is the `stream` Hook?
+The **`stream` function** is a new feature introduced in Open WebUI **0.5.17** that allows you to **intercept and modify streamed model responses** in real time.
+
+Unlike `outlet`, which processes an entire completed response, `stream` operates on **individual chunks** as they are received from the model.
+
+#### 🛠️ When to Use the Stream Hook?
+- Modify **streaming responses** before they are displayed to users.
+- Implement **real-time censorship or cleanup**.
+- **Monitor streamed data** for logging/debugging.
+
+### 📜 Example: Logging Streaming Chunks
+
+Here’s how you can inspect and modify streamed LLM responses:
+```python
+def stream(self, event: dict) -> dict:
+    print(event)  # Print each incoming chunk for inspection
+    return event
+```
+
+> **Example Streamed Events:**
+```json
+{'id': 'chatcmpl-B4l99MMaP3QLGU5uV7BaBM0eDS0jb','choices': [{'delta': {'content': 'Hi'}}]}
+{'id': 'chatcmpl-B4l99MMaP3QLGU5uV7BaBM0eDS0jb','choices': [{'delta': {'content': '!'}}]}
+{'id': 'chatcmpl-B4l99MMaP3QLGU5uV7BaBM0eDS0jb','choices': [{'delta': {'content': ' 😊'}}]}
+```
+📖 **What Happens?**
+- Each line represents a **small fragment** of the model's streamed response.
+- The **`delta.content` field** contains the progressively generated text.
+
+### 🔄 Example: Filtering Out Emojis from Streamed Data
+```python
+def stream(self, event: dict) -> dict:
+    for choice in event.get("choices", []):
+        delta = choice.get("delta", {})
+        if "content" in delta:
+            delta["content"] = delta["content"].replace("😊", "")  # Strip emojis
+    return event
+```
+📖 **Before:** `"Hi 😊"`  
+📖 **After:** `"Hi"`
+
+---
+
+#### 4️⃣ **`outlet` Function (Output Post-Processing)**
 
 The `outlet` function is like a **proofreader**: tidy up the AI's response (or make final changes) *after it’s processed by the LLM.*  
 
@@ -229,9 +280,10 @@ You can, but **it’s not the best practice.**:
 
 By now, you’ve learned:
 1. **Inlet** manipulates **user inputs** (pre-processing).
-2. **Outlet** tweaks **AI outputs** (post-processing).
+2. **Stream** intercepts and modifies **streamed model outputs** (real-time).
-3. Filters are best for lightweight, real-time alterations to the data flow.
+3. **Outlet** tweaks **AI outputs** (post-processing).
-4. With **Valves**, you empower users to configure Filters dynamically for tailored behavior.
+4. Filters are best for lightweight, real-time alterations to the data flow.
+5. With **Valves**, you empower users to configure Filters dynamically for tailored behavior.
 
 ---