Go Backend Init

Go Backend Repository Initialization Skill

Initialize a production-grade Go backend repository following battle-tested patterns from real microservice projects.

When to Use

• User asks to create a new Go backend project
• User wants to scaffold a Go microservice repo
• User needs a Go project template with CI/CD, linting, Docker, etc.

Initialization Checklist

When invoked, walk through these steps in order. Ask the user for project-specific details first:

1. Project name (Go module path, e.g., github.com/org/my-service)
2. Service names (e.g., platform, api, worker — at least one)
3. Go version (default: latest stable, currently 1.25)
4. Database (PostgreSQL with Ent ORM is default; ask if needed)
5. Proto/gRPC (yes/no — if yes, set up buf + generated code structure)
6. System dependencies (any C libraries like libsoxr, etc.)

Directory Structure

Create this structure, adapting service names to the user's input:

.
├── cmd/
│   └── <service>/
│       └── main.go              # Uber FX app entry point
├── internal/
│   ├── configs/                 # Config loading (.env + optional config center)
│   ├── datastore/               # Database client initialization (Ent)
│   ├── grpc/
│   │   ├── servers/             # gRPC + HTTP server lifecycle
│   │   ├── services/            # gRPC service implementations (business logic)
│   │   └── registers/           # Service registration with gRPC server
│   └── models/                  # Data access layer (Ent ORM CRUD)
├── pkg/                         # Reusable packages (errors, utils)
│   └── apierrors/               # Standardized error handling
├── libs/                        # Shared test/logging utilities
├── schema/                      # Ent ORM schema definitions
│   └── generate.go              # go:generate directive for Ent
├── ent/                         # (generated) Ent ORM code — DO NOT EDIT
├── api/
│   └── generated/               # (generated) Proto/gRPC code — DO NOT EDIT
├── hack/                        # Dev scripts
├── .github/
│   ├── actions/
│   │   └── setup-go-env/
│   │       └── action.yml       # Composite action: Go + system deps
│   └── workflows/
│       └── ci.yml               # Lint + Test + Build + Autofix
├── .vscode/
│   ├── settings.json
│   └── extensions.json
├── .editorconfig
├── .gitignore
├── .golangci.yml
├── .tool-versions
├── .env.example
├── cspell.config.yaml
├── renovate.json
├── Dockerfile
├── go.mod
└── CLAUDE.md                    # AI assistant context

File Templates

1. go.mod

module {{MODULE_PATH}}

go {{GO_VERSION}}

require (
	go.uber.org/fx v1.23.0
	// Add Ent ORM if using database
	entgo.io/ent v0.14.4
	// Add gRPC if using proto
	google.golang.org/grpc v1.72.0
	google.golang.org/protobuf v1.36.6
	// Add Echo if using HTTP
	github.com/labstack/echo/v4 v4.13.4
)

After creating, run go mod tidy to resolve dependencies.

2. .editorconfig

root = true

[*.toml]
indent_size = 4
indent_style = space
max_line_length = 100
trim_trailing_whitespace = true

[*.rs]
indent_size = 2
indent_style = space
max_line_length = 100
trim_trailing_whitespace = true

[*.md]
# double whitespace at end of line
# denotes a line break in Markdown
trim_trailing_whitespace = false

[*.{js,ts,vue,tsx,jsx,html,css,json,yaml,yml}]
indent_size = 2
indent_style = space
trim_trailing_whitespace = true

[*.go]
indent_size = 2
indent_style = tab
trim_trailing_whitespace = true

[*.proto]
indent_size = 2
indent_style = space

[*]
charset = utf-8
end_of_line = lf
insert_final_newline = true

3. .golangci.yml

See references/golangci.yml for the full config.

Key principles:

• Use version: "2" format
• Start with default: all, then disable noisy/opinionated linters
• Enable gofmt + goimports formatters
• Exclude generated code paths (api/, ent/) with generated: lax
• Set sane thresholds: dupl: 600, nestif: min-complexity: 9

4. .gitignore

# Binaries for programs and plugins
*.exe
*.exe~
*.dll
*.so
*.dylib
bin/*
dist/*
out/*

# Test binary, built with `go test -c`
*.test

# Output of the go coverage tool
*.out

# Go workspace file
go.work

# Editor and IDE
.idea
*.swp
*.swo
*~
.DS_Store

# Config files (keep example)
config/*
!config/config.yaml

__debug*
.env
.env.local

# Binary outputs (add your service names)
./main

5. CI Workflow (.github/workflows/ci.yml)

See references/ci.yml for the full workflow.

Key jobs:

• Lint (push only): golangci-lint with 7m timeout
• Unit Test: go test ./...
• Nilaway (null safety): static analysis excluding generated code
• Build Test (PR only): go build ./...
• Autofix (PR only): auto-fix lint and commit with [autofix] tag, with conflict guard

6. Composite Action (.github/actions/setup-go-env/action.yml)

name: setup-go-env
description: Setup Go environment with required dependencies
runs:
  using: composite
  steps:
    - uses: actions/setup-go@v6
      with:
        go-version: "^{{GO_VERSION}}"
        cache: true
    # Add system dependencies if needed:
    # - run: |
    #     sudo apt-get update -qq
    #     sudo apt-get install --no-install-recommends -y \
    #       libsoxr-dev \
    #       pkg-config
    #   shell: bash

7. .vscode/settings.json

{
  "go.useLanguageServer": true,
  "go.lintOnSave": "package",
  "go.vetOnSave": "workspace",
  "go.coverOnSave": false,
  "go.lintTool": "golangci-lint-v2",
  "go.lintFlags": [
    "--fast-only",
    "--config=${workspaceFolder}/.golangci.yml"
  ],
  "go.formatTool": "gofmt",
  "go.inferGopath": true,
  "go.coverOnSingleTest": true,
  "go.testTimeout": "900s",
  "go.testFlags": ["-v", "-count=1"],
  "go.toolsManagement.autoUpdate": true,
  "gopls": {
    "build.buildFlags": [],
    "ui.completion.usePlaceholders": true,
    "ui.semanticTokens": true
  },
  "[go]": {
    "editor.insertSpaces": false,
    "editor.formatOnSave": true,
    "editor.codeActionsOnSave": {
      "source.organizeImports": "always"
    }
  },
  "go.testEnvVars": {
    "LOG_LEVEL": "debug"
  }
}

8. .vscode/extensions.json

{
  "recommendations": [
    "streetsidesoftware.code-spell-checker",
    "mikestead.dotenv",
    "EditorConfig.EditorConfig",
    "yzhang.markdown-all-in-one",
    "redhat.vscode-yaml",
    "golang.go",
    "bufbuild.vscode-buf"
  ]
}

9. renovate.json

{
  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
  "extends": [
    "config:recommended",
    ":dependencyDashboard",
    ":semanticPrefixFixDepsChoreOthers",
    ":prHourlyLimitNone",
    ":prConcurrentLimitNone",
    ":ignoreModulesAndTests",
    "group:monorepos",
    "group:recommended",
    "group:allNonMajor",
    "replacements:all",
    "workarounds:all"
  ],
  "rangeStrategy": "bump",
  "labels": ["dependencies"],
  "minimumReleaseAge": "3 days"
}

10. .tool-versions

golang {{GO_VERSION}}

11. cspell.config.yaml

version: "0.2"
ignorePaths: []
dictionaryDefinitions: []
dictionaries: []
words:
  - entgo
  - Ents
  - entsql
  - enttest
  - fxevent
  - nolint
  - stretchr
  - structpb
  - timestamppb
  # Add project-specific words as they arise

12. Dockerfile (multi-stage)

See references/Dockerfile for the full template.

Key patterns:

• Build stage: golang:<version>-bookworm with system deps
• Go mod download first (layer caching)
• Build all services under ./cmd/* dynamically
• Runtime stage: debian:bookworm-slim (minimal image)
• Use --mount=type=cache for Go build cache

13. Uber FX Entry Point (cmd/<service>/main.go)

package main

import (
	"log/slog"
	"os"

	"go.uber.org/fx"
	"go.uber.org/fx/fxevent"

	"{{MODULE_PATH}}/internal/configs"
	"{{MODULE_PATH}}/internal/datastore"
	"{{MODULE_PATH}}/internal/models"
)

func main() {
	app := fx.New(
		fx.WithLogger(func(logger *slog.Logger) fxevent.Logger {
			return &fxevent.SlogLogger{Logger: logger}
		}),
		fx.Provide(func() *slog.Logger {
			return slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
				Level: slog.LevelDebug,
			}))
		}),
		configs.Module(),
		datastore.Module(),
		models.Modules(),
		// Add service-specific modules here
	)
	app.Run()
}

14. Uber FX Constructor Pattern

All services and models MUST follow this pattern:

type NewXXXModelParams struct {
	fx.In
	Client *ent.Client
	Logger *slog.Logger
	Config *configs.Config
}

func NewXXXModel() func(NewXXXModelParams) *XXXModel {
	return func(params NewXXXModelParams) *XXXModel {
		return &XXXModel{
			client: params.Client,
			logger: params.Logger,
			config: params.Config,
		}
	}
}

Register in module files:

// internal/models/models.go
func Modules() fx.Option {
	return fx.Options(
		fx.Provide(xxx.NewXXXModel()),
		// ... other models
	)
}

15. Ent ORM Schema (schema/generate.go)

package schema

//go:generate go run -mod=mod entgo.io/ent/cmd/ent generate ./ --target ../ent --feature=sql/execquery,sql/schemaconfig,sql/lock,sql/upsert

Schema conventions:

• UUID primary keys: field.UUID("id", uuid.UUID{}).Default(uuid.New).Unique().Immutable()
• Soft delete: field.Time("deleted_at").Optional().Nillable()
• Enum status fields: field.Enum("status").Values("ACTIVE", "INACTIVE")
• Timestamps: field.Time("created_at").Default(time.Now).Immutable()

16. .env.example

# =============================================================================
# Application Configuration
# =============================================================================

# Log level: debug, info, warn, error
LOG_LEVEL=info

# =============================================================================
# Database
# =============================================================================
DATABASE_DSN=postgres://user:pass@localhost:5432/dbname?sslmode=disable

# =============================================================================
# Service Ports
# =============================================================================
HTTP_PORT=8080
GRPC_PORT=9090

# =============================================================================
# Authentication
# =============================================================================
# JWT_SECRET=your-secret-here

# =============================================================================
# External Services
# =============================================================================
# REDIS_URL=redis://localhost:6379/0

17. CLAUDE.md Template

Generate a CLAUDE.md that documents:

• Project overview (what it does, key capabilities)
• Technology stack
• Essential commands (run, test, lint, generate)
• Architecture (services, layers, communication)
• Directory structure
• Development workflow (schema changes, API changes, service implementation)
• DI patterns (Uber FX constructors)
• Code style and best practices

Use the reference project's CLAUDE.md as a structural template, but tailor content to the new project.

Post-Initialization Steps

After scaffolding, run these commands:

# Initialize Go module
go mod init {{MODULE_PATH}}
go mod tidy

# Initialize git
git init

# Generate Ent code (if using database)
go generate ./...

# Verify lint config
golangci-lint run

# Verify build
go build ./...

# Create initial commit
git add .
git commit -m "feat: initial project scaffold"

Key Principles

1. Config via .env — no YAML config files; use environment variables with .env for local dev
2. Uber FX everywhere — all DI through FX constructors, never manual instantiation
3. Generated code is sacred — never edit ent/ or api/generated/, always regenerate
4. Soft delete by default — deleted_at field on user-facing entities
5. Structured logging — *slog.Logger injected via FX, never fmt.Println
6. Factory pattern for providers — when supporting multiple backends (TTS, storage, etc.)
7. Layered architecture — Model (CRUD) → Service (business logic) → Registration → Server