diff --git a/main.go b/main.go
index f0831e8..f39c0c2 100644
--- a/main.go
+++ b/main.go
@@ -74,16 +74,38 @@ func NewReading(glucose, ketone float64) Reading {
 	}
 }
 
-/*
-// GKI calculates and returns the Glucose Ketone Index of the reading.
-// The Glucose Ketone Index helps determine the efficiency of glucose and ketone levels within the body. It is
-// calculated as (glucose level in mg/dL / 18) divided by the ketone level.
-func (r Reading) GKI() (float64, error) {
-	if r.Ketone == 0 {
-		return 0, errors.New("ketone level must not be zero to calculate GKI")
+// AppContext is the application data store that holds Records
+type AppContext struct {
+	Records []Record
+}
+
+// LoadRecords will load records from file
+func (ctx *AppContext) LoadRecords(filename string) error {
+	data, err := os.ReadFile(filename)
+	if err != nil {
+		return err
 	}
-	return (r.Glucose / 18) / r.Ketone, nil
-}*/
+	return json.Unmarshal(data, &ctx.Records)
+}
+
+// SaveRecords will save records to a file
+func (ctx *AppContext) SaveRecords(filename string) error {
+	jsonData, err := json.Marshal(ctx.Records)
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(filename, jsonData, 0660)
+}
+
+// AddReading will add a Reading to the AppContext
+func (ctx *AppContext) AddReading(reading Reading) {
+	ctx.Records = append(ctx.Records, Record{Reading: &reading})
+}
+
+// AddNote will a add a Note to the AppContext
+func (ctx *AppContext) AddNote(note Note) {
+	ctx.Records = append(ctx.Records, Record{Note: &note})
+}
 
 func main() {
 	// Take a new reading from the user