type User struct { ID string json:"id" Email string json:"email" Name string json:"name" }

//encore:api public method=GET path=/users/:id func GetUser(ctx context.Context, params *GetUserParams) (*User, error) { // This makes "user" a service }


### Minimal Service Structure

user/ ├── user.go # API endpoints ├── db.go # Database (if needed) └── migrations/ # SQL migrations └── 1_create_users.up.sql


## Application Patterns

### Single Service (Recommended Start)

Best for new projects - start simple, split later if needed:

my-app/ ├── encore.app ├── go.mod ├── api.go # All endpoints ├── db.go # Database └── migrations/ └── 1_initial.up.sql


### Multi-Service

For distributed systems with clear domain boundaries:

my-app/ ├── encore.app ├── go.mod ├── user/ │ ├── user.go │ ├── db.go │ └── migrations/ ├── order/ │ ├── order.go │ ├── db.go │ └── migrations/ └── notification/ └── notification.go


### Large Application (System-based)

Group related services into systems:

my-app/ ├── encore.app ├── go.mod ├── commerce/ │ ├── order/ │ │ └── order.go │ ├── cart/ │ │ └── cart.go │ └── payment/ │ └── payment.go ├── identity/ │ ├── user/ │ │ └── user.go │ └── auth/ │ └── auth.go └── comms/ ├── email/ │ └── email.go └── push/ └── push.go


## Service-to-Service Calls

Just import and call the function directly - Encore handles the RPC:

```go
package order

import (
    "context"
    "myapp/user"  // Import the user service
)

//encore:api auth method=GET path=/orders/:id
func GetOrderWithUser(ctx context.Context, params *GetOrderParams) (*OrderWithUser, error) {
    order, err := getOrder(ctx, params.ID)
    if err != nil {
        return nil, err
    }
    
    // This becomes an RPC call - Encore handles it
    orderUser, err := user.GetUser(ctx, &user.GetUserParams{ID: order.UserID})
    if err != nil {
        return nil, err
    }
    
    return &OrderWithUser{Order: order, User: orderUser}, nil
}

When to Split Services

Split when you have:

Signal	Action
Different scaling needs	Split (e.g., auth vs analytics)
Different deployment cycles	Split
Clear domain boundaries	Split
Shared database tables	Keep together
Tightly coupled logic	Keep together
Just organizing code	Use sub-packages, not services

Internal Helpers (Non-Service Packages)

Create packages without //encore:api endpoints for shared code:

my-app/
├── user/
│   └── user.go       # Service (has API)
├── order/
│   └── order.go      # Service (has API)
└── internal/
    ├── util/
    │   └── util.go   # Not a service (no API)
    └── validation/
        └── validate.go

Guidelines

A package becomes a service when it has //encore:api endpoints
Services cannot be nested within other services
Start with one service, split when there's a clear reason
Cross-service calls look like regular function calls
Each service can have its own database
Package names should be lowercase, descriptive
Don't create services just for code organization - use sub-packages instead

encore-go-service

Encore Go Service Structure

Instructions

Creating a Service