When writing technical articles, a good architecture diagram is worth a thousand words. Mermaid is a tool that uses text-based code to create diagrams, making it perfect for use in Markdown blogs.

What is Mermaid?

Mermaid is a JavaScript-based diagramming tool that allows you to create various charts using simple syntax similar to Markdown:

Flowchart
Sequence Diagram
State Diagram
Gantt Chart
Entity Relationship (ER) Diagram

Example: AI Application Architecture

Below is a typical AI application architecture diagram:

graph LR
    A["User Input"] --> B["Prompt Template"]
    B --> C["LLM Large Model"]
    C --> D["Result Parsing"]
    D --> E["Business Logic"]
    E --> F["Return to User"]

Example: AI Agent Workflow

A typical workflow for an AI Agent:

graph LR
    A["Receive Task"] --> B{"Need Tools?"}
    B -->|"Yes"| C["Select Tool"]
    C --> D["Call Tool"]
    D --> E["Get Result"]
    E --> B
    B -->|"No"| F["Generate Answer"]
    F --> G["Return Result"]

Example: User Authentication Sequence Diagram

A typical user login sequence:

sequenceDiagram
    participant U as User
    participant F as Frontend
    participant B as Backend
    participant D as Database

    U->>F: Enter username and password
    F->>B: POST /api/login
    B->>D: Query user
    D-->>B: Return user info
    B-->>F: Return JWT Token
    F-->>U: Login successful

How to Use in a Blog?

In a Markdown file, just use three backticks followed by mermaid:

```mermaid
graph LR
    A["Start"] --> B["End"]
```

It's that simple! The blog framework will automatically render it into a beautiful diagram.

Tips

Keep it simple — Don't use too many nodes in a diagram; 7-10 is optimal.
Use meaningful text — Node labels should be self-explanatory.
Choose the right diagram type — Use flowcharts for processes and sequence diagrams for interactions.
Pay attention to direction — LR means left to right, TD means top to bottom.

Summary

Mermaid is a great helper for technical writers. Drawing diagrams with text-based code makes version control easy and ensures consistency between diagrams and articles.

I suggest that when writing technical blogs, if you encounter a complex process, draw a Mermaid diagram — your readers will thank you!

In my next article, I plan to share how to build a simple AI Agent using LangChain.