claudecode-boilerplate/.claude/skills/functional-design/template.md

Functional Design Document

System Architecture Diagram

graph TB
    User[User]
    CLI[CLI Layer]
    Service[Service Layer]
    Data[Data Layer]

    User --> CLI
    CLI --> Service
    Service --> Data

Technology Stack

Category	Technology	Selection Rationale
Language	[Language name]	[Rationale]
Framework	[Name]	[Rationale]
Database	[Name]	[Rationale]
Tools	[Name]	[Rationale]

Data Model Definition

Entity: [Entity Name]

interface [EntityName] {
  id: string;              // UUID
  [field1]: [type];        // [description]
  [field2]: [type];        // [description]
  createdAt: Date;         // Creation timestamp
  updatedAt: Date;         // Update timestamp
}

Constraints:

• [Constraint 1]
• [Constraint 2]

ER Diagram

erDiagram
    ENTITY1 ||--o{ ENTITY2 : has
    ENTITY1 {
        string id PK
        string field1
        datetime createdAt
    }
    ENTITY2 {
        string id PK
        string entity1Id FK
        string field1
    }

Component Design

[Component 1]

Responsibilities:

• [Responsibility 1]
• [Responsibility 2]

Interface:

class [ComponentName] {
  [method1]([params]): [return];
  [method2]([params]): [return];
}

Dependencies:

• [Dependency 1]
• [Dependency 2]

Use Case Diagram

[Use Case 1]

sequenceDiagram
    participant User
    participant CLI
    participant Service
    participant Data

    User->>CLI: [action1]
    CLI->>Service: [action2]
    Service->>Data: [action3]
    Data-->>Service: [response]
    Service-->>CLI: [response]
    CLI-->>User: [result]

Flow Description:

1. [Step 1]
2. [Step 2]
3. [Step 3]

Screen Transition Diagram (if applicable)

stateDiagram-v2
    [*] --> State1
    State1 --> State2: [action]
    State2 --> State3: [action]
    State3 --> [*]

API Design (if applicable)

[Endpoint 1]

POST /api/[resource]

Request:

{
  "[field]": "[value]"
}

Response:

{
  "id": "uuid",
  "[field]": "[value]"
}

Error Responses:

• 400 Bad Request: [Condition]
• 404 Not Found: [Condition]
• 500 Internal Server Error: [Condition]

Algorithm Design (if applicable)

[Algorithm Name]

Purpose: [Description]

Calculation Logic:

Step 1: [Step Name]

• [Detailed description]
• Formula: [formula]
• Score range: 0-100 points

Step 2: [Step Name]

• [Detailed description]
• Formula: [formula]
• Score range: 0-100 points

Step 3: Total Score Calculation

• Weighted average: Total Score = (Step 1 × Weight 1) + (Step 2 × Weight 2)
• Weight allocation:
  • Step 1: [%]
  • Step 2: [%]

Step 4: Classification

• [Classification 1]: Score >= [threshold]
• [Classification 2]: [threshold] <= Score < [threshold]
• [Classification 3]: Score < [threshold]

Implementation Example:

function [algorithmName]([params]): [return] {
  // Step 1
  const score1 = [calculation];

  // Step 2
  const score2 = [calculation];

  // Total score
  const totalScore = (score1 * weight1) + (score2 * weight2);

  // Classification
  if (totalScore >= threshold1) return '[classification1]';
  if (totalScore >= threshold2) return '[classification2]';
  return '[classification3]';
}

UI Design (if applicable)

Table Display

Display Items:

Item	Description	Format
[Item 1]	[Description]	[Format]
[Item 2]	[Description]	[Format]

Color Coding

Color Usage:

Interactive Mode (if applicable)

Operation Flow:

1. [Operation 1]
2. [Operation 2]
3. [Operation 3]

File Structure (if applicable)

Data Storage Format:

[directory]/
├── [file1].json    # [description]
└── [file2].json    # [description]

File Content Example:

{
  "[field]": "[value]"
}

Performance Optimization

Security Considerations

Error Handling

Error Classification

Error Category	Handling	Display to User
[Category 1]	[Handling details]	[Message]
[Category 2]	[Handling details]	[Message]

Testing Strategy

Unit Tests

• [Target 1]
• [Target 2]

Integration Tests

• [Scenario 1]
• [Scenario 2]

E2E Tests

• [Scenario 1]
• [Scenario 2]