Encore Go Authentication Instructions
Encore Go provides a built-in authentication system using the //encore:authhandler annotation.
- Create an Auth Handler package auth
import ( "context" "encore.dev/beta/auth" "encore.dev/beta/errs" )
// AuthParams defines what the auth handler receives
type AuthParams struct {
Authorization string header:"Authorization"
}
// AuthData defines what authenticated requests have access to type AuthData struct { UserID string Email string Role string }
//encore:authhandler func Authenticate(ctx context.Context, params AuthParams) (auth.UID, AuthData, error) { token := strings.TrimPrefix(params.Authorization, "Bearer ")
payload, err := verifyToken(token)
if err != nil {
return "", nil, &errs.Error{
Code: errs.Unauthenticated,
Message: "invalid token",
}
}
return auth.UID(payload.UserID), &AuthData{
UserID: payload.UserID,
Email: payload.Email,
Role: payload.Role,
}, nil
}
- Protect Endpoints package user
import "context"
// Protected endpoint - requires authentication //encore:api auth method=GET path=/profile func GetProfile(ctx context.Context) (*Profile, error) { // Only authenticated users reach here }
// Public endpoint - no authentication required //encore:api public method=GET path=/health func Health(ctx context.Context) (*HealthResponse, error) { return &HealthResponse{Status: "ok"}, nil }
- Access Auth Data in Endpoints package user
import ( "context" "encore.dev/beta/auth" myauth "myapp/auth" // Import your auth package )
//encore:api auth method=GET path=/profile func GetProfile(ctx context.Context) (*Profile, error) { // Get the user ID userID, ok := auth.UserID() if !ok { // Should not happen with auth endpoint }
// Get full auth data
data := auth.Data().(*myauth.AuthData)
return &Profile{
UserID: string(userID),
Email: data.Email,
Role: data.Role,
}, nil
}
Auth Handler Signature
The auth handler must:
Have the //encore:authhandler annotation Accept context.Context and a params struct pointer Return (auth.UID, YourAuthData, error) //encore:authhandler func MyAuthHandler(ctx context.Context, params Params) (auth.UID, *AuthData, error)
Auth Handler Behavior Scenario Returns Result Valid credentials (uid, data, nil) Request authenticated Invalid credentials ("", nil, err) with errs.Unauthenticated 401 response Other error ("", nil, err) Request aborted Common Auth Patterns JWT Token Validation import ( "github.com/golang-jwt/jwt/v5" "encore.dev/config" )
var secrets struct { JWTSecret config.String }
func verifyToken(tokenString string) (Claims, error) { token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(t jwt.Token) (interface{}, error) { return []byte(secrets.JWTSecret()), nil }) if err != nil { return nil, err }
claims, ok := token.Claims.(*Claims)
if !ok || !token.Valid {
return nil, errors.New("invalid token")
}
return claims, nil
}
API Key Authentication //encore:authhandler func Authenticate(ctx context.Context, params AuthParams) (auth.UID, AuthData, error) { apiKey := params.Authorization
user, err := db.QueryRow[User](ctx, `
SELECT id, email, role FROM users WHERE api_key = $1
`, apiKey)
if err != nil {
return "", nil, &errs.Error{
Code: errs.Unauthenticated,
Message: "invalid API key",
}
}
return auth.UID(user.ID), &AuthData{
UserID: user.ID,
Email: user.Email,
Role: user.Role,
}, nil
}
Cookie-Based Auth
type AuthParams struct {
Cookie string header:"Cookie"
}
//encore:authhandler func Authenticate(ctx context.Context, params AuthParams) (auth.UID, AuthData, error) { sessionID := parseCookie(params.Cookie, "session") if sessionID == "" { return "", nil, &errs.Error{ Code: errs.Unauthenticated, Message: "no session", } }
session, err := getSession(ctx, sessionID)
if err != nil || session.ExpiresAt.Before(time.Now()) {
return "", nil, &errs.Error{
Code: errs.Unauthenticated,
Message: "session expired",
}
}
return auth.UID(session.UserID), &AuthData{
UserID: session.UserID,
Email: session.Email,
Role: session.Role,
}, nil
}
Service-to-Service Auth
Auth data automatically propagates in internal service calls:
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 }
// Auth is automatically propagated to this call
profile, err := user.GetProfile(ctx)
if err != nil {
return nil, err
}
return &OrderWithUser{Order: order, User: profile}, nil
}
Guidelines Only one //encore:authhandler per application Return auth.UID as the first return value (user identifier) Return your custom AuthData struct as second value Use auth.UserID() to get the authenticated user ID Use auth.Data() and type assert to get full auth data Auth propagates automatically in service-to-service calls Keep auth handlers fast - they run on every authenticated request