diff --git a/docs/index.md b/docs/index.md
index 3258b51..cd3c002 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -8,6 +8,12 @@ nav_order: 1
 
 A [100-line](https://github.com/zachary62/miniLLMFlow/blob/main/minillmflow/__init__.py) minimalist LLM framework for *Agents, Task Decomposition, RAG, etc*.
 
+<div align="center">
+  <img src="https://github.com/zachary62/miniLLMFlow/blob/main/assets/minillmflow.jpg?raw=true" width="400"/>
+</div>
+
+## Core Abstraction
+
 We model the LLM workflow as a **Nested Directed Graph**:
 - **Nodes** handle simple (LLM) tasks.
 - Nodes connect through **Actions** (labeled edges) for *Agents*.  
@@ -16,12 +22,7 @@ We model the LLM workflow as a **Nested Directed Graph**:
 - **Batch** Nodes/Flows for data-intensive tasks.
 - **Async** Nodes/Flows allow waits or **Parallel** execution
 
-<div align="center">
-  <img src="https://github.com/zachary62/miniLLMFlow/blob/main/assets/minillmflow.jpg?raw=true" width="400"/>
-</div>
-
-## Core Abstraction
-
+To learn more:
 - [Node](./node.md)
 - [Flow](./flow.md)
 - [Communication](./communication.md)
@@ -29,20 +30,32 @@ We model the LLM workflow as a **Nested Directed Graph**:
 - [(Advanced) Async](./async.md)
 - [(Advanced) Parallel](./parallel.md)
 
-## Preparation
+## LLM Wrapper & Tools
 
+**We DO NOT provide built-in LLM wrappers and tools!**
+
+I believe it is a *bad practice* to provide low-level implementations in a general framework:
+- **APIs change frequently.** Hardcoding them makes maintenance a nightmare.
+- You may need **flexibility.** E.g., using fine-tunined LLMs or deploying local ones.
+- You may need **optimizations.** E.g., prompt caching, request batching, response streaming...
+
+We provide some simple example implementations:
 - [LLM Wrapper](./llm.md)
 - [Tool](./tool.md)
 
-## Paradigm Implementation
+## Paradigm
 
+Based on the core abstraction, we implement common high-level paradigms:
+
+- [Structured Output](./structure.md)
 - Task Decomposition
-- Agent
-- Map Reduce
 - RAG
-- Structured Output
+- Chat Memory
+- Map Reduce
+- Agent
+- Multi-Agent
 - Evaluation
 
 ## Example Projects
 
-- TODO
+- Coming soon ... 
diff --git a/docs/llm.md b/docs/llm.md
index 9229940..55e44ab 100644
--- a/docs/llm.md
+++ b/docs/llm.md
@@ -62,9 +62,3 @@ def call_llm(prompt):
     return response
 ```
 
-## Why Not Provide a Built-in LLM Wrapper?
-I believe it is a **bad practice** to provide LLM-specific implementations in a general framework:
-- **LLM APIs change frequently**. Hardcoding them makes maintenance a nighmare.
-- You may need **flexibility** to switch vendors, use fine-tuned models, or deploy local LLMs.
-- You may need **optimizations** like prompt caching, request batching, or response streaming.
-
diff --git a/docs/paradigm.md b/docs/paradigm.md
new file mode 100644
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+++ b/docs/paradigm.md
@@ -0,0 +1,6 @@
+---
+layout: default
+title: "Paradigm"
+nav_order: 4
+has_children: true
+---
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diff --git a/docs/structure.md b/docs/structure.md
new file mode 100644
index 0000000..1138f5c
--- /dev/null
+++ b/docs/structure.md
@@ -0,0 +1,111 @@
+---
+layout: default
+title: "Structured Output"
+parent: "Paradigm"
+nav_order: 1
+---
+
+# Structured Output
+
+In many use cases, you may want the LLM to output a specific structure, such as a list or a dictionary with predefined keys.
+
+There are several approaches to achieve a structured output:
+- **Prompting** the LLM to strictly return a defined structure.
+- Using LLMs that natively support **schema enforcement**.
+- **Post-processing** the LLM’s response to extract structured content.
+
+In practice, **Prompting** is simple and reliable for modern LLMs.
+
+## Example Use Cases
+
+1. **Extracting Key Information**  
+
+```yaml
+product:
+  name: Widget Pro
+  price: 199.99
+  description: |
+    A high-quality widget designed for professionals.
+    Recommended for advanced users.
+```
+
+2. **Summarizing Documents into Bullet Points**  
+
+```yaml
+summary:
+  - This product is easy to use.
+  - It is cost-effective.
+  - Suitable for all skill levels.
+```
+
+3. **Generating Configuration Files**  
+
+```yaml
+server:
+  host: 127.0.0.1
+  port: 8080
+  ssl: true
+```
+
+## Prompt Engineering
+
+When prompting the LLM to produce **structured** output:
+1. **Wrap** the structure in code fences (e.g., ```yaml).
+2. **Validate** that all required fields exist (and retry if necessary).
+
+### Example Text Summarization
+
+```python
+class SummarizeNode(Node):
+    def exec(self, prep_res):
+        # Suppose `prep_res` is the text to summarize.
+        prompt = f"""
+Please summarize the following text as YAML, with exactly 3 bullet points
+
+{prep_res}
+
+Now, output:
+```yaml
+summary:
+  - bullet 1
+  - bullet 2
+  - bullet 3
+```"""
+        response = call_llm(prompt)
+        yaml_str = response.split("```yaml")[1].split("```")[0].strip()
+        
+        import yaml
+        structured_result = yaml.safe_load(yaml_str)
+
+        assert "summary" in structured_result
+        assert isinstance(structured_result["summary"], list)
+
+        return structured_result
+```
+
+### Why YAML instead of JSON?
+
+Current LLMs struggle with escaping. YAML is easier with strings since they don’t always need quotes.
+
+**In JSON**  
+
+```json
+{
+  "dialogue": "Alice said: \"Hello Bob.\\nHow are you?\\nI am good.\""
+}
+```
+
+- Every double quote inside the string must be escaped with `\"`.
+- Each newline in the dialogue must be represented as `\n`.
+
+**In YAML**  
+
+```yaml
+dialogue: |
+  Alice said: "Hello Bob.
+  How are you?
+  I am good."
+```
+
+- No need to escape interior quotes—just place the entire text under a block literal (`|`).
+- Newlines are naturally preserved without needing `\n`.
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