/mermaid-skill

Worked Examples

Four complete prompt → .mmd → output walkthroughs. Copy the structure, not the content.

Example 1: API Authentication Flow

User prompt:

Create a sequence diagram for JWT authentication

Generated .mmd:

sequenceDiagram
  participant C as Client
  participant G as API Gateway
  participant A as Auth Service
  participant D as Database

  C->>G: POST /login {email, password}
  G->>A: validate(credentials)
  A->>D: SELECT user WHERE email=?
  D-->>A: user record
  A-->>A: verify password hash
  A-->>G: 200 OK + JWT token
  G-->>C: {token: "eyJhbG..."}

Output files: auth-flow.mmd + auth-flow.png

Example 2: Microservices Architecture

User prompt:

Draw an e-commerce microservices architecture

Generated .mmd:

flowchart TD
  subgraph Clients
    M[Mobile App]
    W[Web App]
  end

  GW[API Gateway]

  subgraph Services
    US[User Service]
    OS[Order Service]
    PS[Product Service]
    PAY[Payment Service]
  end

  subgraph Data
    UDB[(User DB)]
    ODB[(Order DB)]
    PDB[(Product DB)]
    REDIS[(Redis Cache)]
  end

  M & W --> GW
  GW --> US & OS & PS & PAY
  US --> UDB
  OS --> ODB
  PS --> PDB
  PAY --> REDIS

Output files: ecommerce-arch.mmd + ecommerce-arch.png

Example 3: Order State Machine

User prompt:

Show order lifecycle states

Generated .mmd:

stateDiagram-v2
  [*] --> Pending : order created
  Pending --> Confirmed : payment success
  Pending --> Cancelled : timeout/cancel
  Confirmed --> Shipped : dispatched
  Shipped --> Delivered : received
  Delivered --> [*]
  Cancelled --> [*]

Output files: order-states.mmd + order-states.png

Example 4: Cloud Architecture

User prompt:

Draw a simple service architecture for an API

Generated .mmd:

architecture-beta
  group api(cloud)[API]

  service gateway(internet)[Gateway] in api
  service db(database)[Database] in api
  service cache(disk)[Cache] in api

  gateway:R --> L:db
  gateway:B --> T:cache

Output files: api-architecture.mmd + api-architecture.png