Golang Backend Architecture Expert

Expert assistant for Golang backend architecture with Gin Server, Layered Architecture, sqlc, PostgreSQL (Supabase), and API authentication.

How It Works Analyzes service requirements and existing codebase Queries Gin documentation via Context7 (/websites/gin-gonic_en) Applies layered architecture patterns (Handler → Service → Repository) Provides implementation with proper error handling and testing Usage Initialize SQLC bash /mnt/skills/user/golang-architect/scripts/sqlc-init.sh [project-dir] [db-engine]

Arguments:

project-dir - Project directory (default: current directory) db-engine - Database engine: postgresql, mysql, sqlite3 (default: postgresql)

Examples:

bash /mnt/skills/user/golang-architect/scripts/sqlc-init.sh bash /mnt/skills/user/golang-architect/scripts/sqlc-init.sh ./my-project postgresql

Documentation Resources

Context7 Library ID: /websites/gin-gonic_en (117 snippets, Score: 90.8)

Official Documentation:

Gin: https://gin-gonic.com/en/docs/ sqlc: https://docs.sqlc.dev/ Supabase: Use mcp__supabase__* tools go-symphony: https://github.com/Tomlord1122/go-symphony Layered Architecture Template project/ ├── cmd/ │ └── api/ │ └── main.go # Entry point ├── internal/ │ ├── handler/ # HTTP handlers (Gin) │ │ └── user_handler.go │ ├── service/ # Business logic │ │ └── user_service.go │ ├── repository/ # Data access (sqlc) │ │ └── user_repository.go │ ├── middleware/ # Auth, logging, CORS │ │ └── auth.go │ └── dto/ # Data Transfer Objects │ └── user_dto.go ├── pkg/ # Shared utilities ├── db/ │ ├── migrations/ # SQL migrations │ └── queries/ # sqlc SQL files ├── sqlc.yaml └── go.mod

sqlc Configuration

sqlc.yaml

version: "2" sql: - engine: "postgresql" queries: "db/queries/" schema: "db/migrations/" gen: go: package: "repository" out: "internal/repository" sql_package: "pgx/v5" emit_json_tags: true emit_interface: true

Handler Pattern type UserHandler struct { service *service.UserService }

func NewUserHandler(s service.UserService) UserHandler { return &UserHandler{service: s} }

func (h UserHandler) GetUser(c gin.Context) { id := c.Param("id") user, err := h.service.GetUser(c.Request.Context(), id) if err != nil { c.JSON(http.StatusNotFound, gin.H{"error": err.Error()}) return } c.JSON(http.StatusOK, user) }

Middleware Pattern func AuthMiddleware(jwtSecret string) gin.HandlerFunc { return func(c *gin.Context) { token := c.GetHeader("Authorization") if token == "" { c.AbortWithStatusJSON(401, gin.H{"error": "unauthorized"}) return } // Validate token... c.Set("userID", claims.UserID) c.Next() } }

Error Handling // Custom error types type AppError struct { Code int json:"code" Message string json:"message" }

func (e *AppError) Error() string { return e.Message }

// Error middleware func ErrorHandler() gin.HandlerFunc { return func(c gin.Context) { c.Next() if len(c.Errors) > 0 { err := c.Errors.Last().Err if appErr, ok := err.(AppError); ok { c.JSON(appErr.Code, appErr) return } c.JSON(500, gin.H{"error": "internal server error"}) } } }

Present Results to User

When providing Go backend solutions:

Follow Go conventions (Effective Go, uber-go/guide) Use dependency injection for testability Provide complete error handling examples Include context propagation for cancellation Show corresponding tests when appropriate Troubleshooting

"sqlc generate fails"

Verify PostgreSQL syntax in queries Check schema matches query expectations Run sqlc vet for detailed errors

"Gin handler not receiving body"

Ensure Content-Type: application/json header Check if body was already read (bind only once) Use ShouldBindJSON instead of BindJSON for error control

"Context cancelled"

Propagate context through all layers Check for long-running operations without timeout