env working but auth not yet

internal/api/types.go

@@ -2,9 +2,27 @@ package api
 
 import (
 	"encoding/json"
+	"fmt"
 	"time"
 )
 
+// APIError represents an error returned by the API
+type APIError struct {
+	StatusCode int
+	Message    string
+}
+
+func (e *APIError) Error() string {
+	return fmt.Sprintf("API request failed with status %d: %s", e.StatusCode, e.Message)
+}
+
+// Error types for API responses
+type ErrNotFound struct{}
+func (e ErrNotFound) Error() string { return "resource not found" }
+
+type ErrBadRequest struct{}
+func (e ErrBadRequest) Error() string { return "bad request" }
+
 // Time represents a Garmin Connect time value
 type Time time.Time
 
@@ -74,4 +92,4 @@ type BodyComposition struct {
 type BodyCompositionRequest struct {
 	StartDate Time `json:"startDate"`
 	EndDate   Time `json:"endDate"`
-}
+}