update design doc

docs/guide.md

@@ -7,13 +7,13 @@ nav_order: 1
 
 # LLM System Design Guidance
 
-{: .important }
-> Use LLMs to help with system design and implementation wherever possible.
 
-## Recommended LLM Project Structure:
+## Example LLM Project File Structure
 
 ```
 my_project/
+├── main.py
+├── flow.py
 ├── utils/
 │   ├── __init__.py
 │   ├── call_llm.py
@@ -22,32 +22,96 @@ my_project/
 │   ├── __init__.py
 │   ├── test_flow.py
 │   └── test_nodes.py
-├── main.py
-├── flow.py
 ├── requirements.txt
-└── design.md
+└── docs/
+    └── design.md
 ```
 
 
+### `docs/`
+
+Store the documentation of the project.
+
+It should include a `design.md` file, which describes 
+- Project requirements
+- Required utility functions
+- High-level flow with a mermaid diagram
+- Shared memory data structure
+- For each node, discuss
+  - Node purpose and design (e.g., should it be a batch or async node?)
+  - How the data shall be read (for `prep`) and written (for `post`)
+  - How the data shall be processed (for `exec`)
+
+### `utils/`
+
+Houses functions for external API calls (e.g., LLMs, web searches, etc.). 
+
+It’s recommended to dedicate one Python file per API call, with names like `call_llm.py` or `search_web.py`. Each file should include:
+
+- The function to call the API
+- A main function to run that API call
+
+For instance, here’s a simplified `call_llm.py` example:
+
+```python
+from openai import OpenAI
+
+def call_llm(prompt):
+    client = OpenAI(api_key="YOUR_API_KEY_HERE")
+    response = client.chat.completions.create(
+        model="gpt-4o",
+        messages=[{"role": "user", "content": prompt}]
+    )
+    return response.choices[0].message.content
+
+def main():
+    prompt = "Hello, how are you?"
+    print(call_llm(prompt))
+
+if __name__ == "__main__":
+    main()
+```
+
+### `main.py`
+
+Serves as the project’s entry point.
+
+### `flow.py`
+
+Implements the application’s flow, starting with node followed by the flow structure.
+
+
+### `tests/`
+
+Optionally contains all tests. Use `pytest` for testing flows, nodes, and utility functions.
+For example, `test_call_llm.py` might look like:
+
+```python
+from utils.call_llm import call_llm
+
+def test_call_llm():
+    prompt = "Hello, how are you?"
+    assert call_llm(prompt) is not None
+```
+
 ## System Design Steps:
 
 1. **Understand Requirements**  
-   - Clarify the app’s needs and requirements.  
-   - Determine data access (e.g., from files or databases). 
+   - Clarify application objectives.
+   - Determine and implement the necessary utility functions (e.g., for LLMs, web searches, file handling).
 
 2. **High-Level Flow Design**  
-   - Represent the process as a *Nested Directed Graph*.  
-   - Identify possible branching for *Node Action*.  
-   - Identify data-heavy steps for *Batch*.
+   - Design the flow on how to use the utility functions to achieve the objectives.
+   - Identify possible branching for *Node Action* and data-heavy steps for *Batch*.
 
 3. **Shared Memory Structure**  
    - For small apps, in-memory data is sufficient.  
    - For larger or persistent needs, use a database.  
-   - Define schemas or data structures and plan how states will be stored and updated.
+   - Define data schemas or structures and how states are stored or updated.
 
 4. **Implementation**  
-   - Rely on LLMs for coding tasks.  
    - Start with minimal, straightforward code (e.g., avoid heavy type checking initially).
+   - For each node, specify data access (for `prep` and `post`) and data processing (for `exec`).
 
 5. **Optimization**  
    - *Prompt Engineering:* Provide clear instructions and examples to reduce ambiguity.