Task Management REST API - Go Implementation

A task management REST API built with Go and the Gin framework. This implementation provides CRUD operations for tasks with support for pagination, filtering, and status management.

Directory Structure

.
├── cmd/
│   └── rest-server/        # REST server entry point
│       └── main.go
├── internal/               # Private application code
│   ├── models/            # Data models and types
│   │   └── task.go
│   └── services/          # Business logic
│       └── task_service.go
├── rest/                   # REST API implementation
│   └── server/            # HTTP handlers and routing
│       └── handlers.go
├── go.mod                  # Go module definition
└── README.md

Prerequisites

• Go 1.21 or higher

Installation

# Download dependencies
go mod download

Running the Server

# Run directly
go run cmd/rest-server/main.go

# Or build and run
go build -o bin/rest-server cmd/rest-server/main.go
./bin/rest-server

Port Configuration: The server reads the port from the PORT environment variable. If not set, it defaults to 8080.

# Run on custom port
PORT=3000 go run cmd/rest-server/main.go

API Endpoints

Health Check

• GET /health - Server health status

Tasks

• GET /api/v1/tasks - List all tasks
  • Query params: page_size, page_token, status, assigned_to, tags, sort_order
• GET /api/v1/tasks/:id - Get a specific task
• POST /api/v1/tasks - Create a new task
• PUT /api/v1/tasks/:id - Update a task
• PATCH /api/v1/tasks/:id/status - Update task status only
• DELETE /api/v1/tasks/:id - Delete a task

Task Model

Task Statuses

• pending - Task is pending
• in_progress - Task is being worked on
• completed - Task is completed
• cancelled - Task is cancelled
• on_hold - Task is on hold

Task Priorities

• low - Low priority
• medium - Medium priority
• high - High priority
• critical - Critical priority

Task Fields

{
  "id": "uuid",
  "title": "string (required, 1-200 chars)",
  "description": "string",
  "status": "TaskStatus",
  "priority": "TaskPriority",
  "tags": ["string"],
  "created_by": "string",
  "assigned_to": "string (optional)",
  "created_at": "timestamp",
  "updated_at": "timestamp",
  "due_date": "timestamp (optional)",
  "completed_at": "timestamp (optional)"
}

Example Usage

Create a Task

curl -X POST http://localhost:8080/api/v1/tasks \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Learn Go",
    "description": "Complete the Go tutorial",
    "priority": "high",
    "tags": ["learning", "go"]
  }'

List Tasks

# All tasks
curl http://localhost:8080/api/v1/tasks

# Filtered by status
curl http://localhost:8080/api/v1/tasks?status=pending

# With pagination
curl http://localhost:8080/api/v1/tasks?page_size=10&sort_order=priority_desc

Update Task Status

curl -X PATCH http://localhost:8080/api/v1/tasks/{id}/status \
  -H "Content-Type: application/json" \
  -d '{"status": "in_progress"}'

Delete a Task

curl -X DELETE http://localhost:8080/api/v1/tasks/{id}

Features

• Gin Framework - Fast HTTP router with middleware support
• In-memory Storage - Task data stored in memory (no database required)
• Validation - Request validation with struct tags
• Error Handling - Consistent error responses with status codes
• CORS Support - Cross-origin resource sharing enabled
• Pagination - Page-based pagination with tokens
• Filtering & Sorting - Query by status, assignee, tags; sort by various fields
• UUID-based IDs - Unique identifiers for all tasks

HTTP Status Codes

• 200 OK - Successful GET/PUT/PATCH request
• 201 Created - Successful POST request
• 204 No Content - Successful DELETE request
• 400 Bad Request - Validation error or invalid input
• 404 Not Found - Resource not found
• 500 Internal Server Error - Server error

Error Response Format

{
  "error": {
    "code": "ERROR_CODE",
    "message": "Human readable error message"
  }
}

Common error codes:

• VALIDATION_ERROR - Invalid input data
• NOT_FOUND - Resource not found
• INTERNAL_ERROR - Server error