diff --git a/console/graph.go b/console/graph.go
index 1689daa6..0ed58605 100644
--- a/console/graph.go
+++ b/console/graph.go
@@ -15,11 +15,11 @@ import (
 // graphQuery describes the input for the /graph endpoint.
 type graphQuery struct {
 	Start      time.Time     `json:"start" binding:"required"`
-	End        time.Time     `json:"end" binding:"required"`
-	Points     int           `json:"points" binding:"required"` // minimum number of points
-	Dimensions []queryColumn `json:"dimensions"`                // group by ...
-	Limit      int           `json:"limit"`                     // limit product of dimensions
-	Filter     queryFilter   `json:"filter"`                    // where ...
+	End        time.Time     `json:"end" binding:"required,gtfield=Start"`
+	Points     int           `json:"points" binding:"required,min=5,max=2000"` // minimum number of points
+	Dimensions []queryColumn `json:"dimensions"`                               // group by ...
+	Limit      int           `json:"limit" binding:"isdefault|min=1,max=50"`   // limit product of dimensions
+	Filter     queryFilter   `json:"filter"`                                   // where ...
 }
 
 // graphQueryToSQL converts a graph query to an SQL request
@@ -96,21 +96,6 @@ func (c *Component) graphHandlerFunc(gc *gin.Context) {
 		gc.JSON(http.StatusBadRequest, gin.H{"message": helpers.Capitalize(err.Error())})
 		return
 	}
-	if query.Start.After(query.End) {
-		gc.JSON(http.StatusBadRequest, gin.H{"message": "Start should not be after end"})
-		return
-	}
-	if query.Points < 5 || query.Points > 2000 {
-		gc.JSON(http.StatusBadRequest, gin.H{"message": "Points should be >= 5 and <= 2000"})
-		return
-	}
-	if query.Limit == 0 {
-		query.Limit = 10
-	}
-	if query.Limit < 5 || query.Limit > 50 {
-		gc.JSON(http.StatusBadRequest, gin.H{"message": "Limit should be >= 5 and <= 50"})
-		return
-	}
 
 	sqlQuery, err := query.toSQL()
 	if err != nil {
diff --git a/console/widgets.go b/console/widgets.go
index 62f99eee..209f3c79 100644
--- a/console/widgets.go
+++ b/console/widgets.go
@@ -4,9 +4,10 @@ import (
 	"fmt"
 	"net/http"
 	"reflect"
-	"strconv"
 	"time"
 
+	"akvorado/common/helpers"
+
 	"github.com/gin-gonic/gin"
 )
 
@@ -169,19 +170,22 @@ LIMIT 5
 	gc.JSON(http.StatusOK, gin.H{"top": results})
 }
 
+type widgetParameters struct {
+	Points uint64 `form:"points" binding:"isdefault|min=5,max=1000"`
+}
+
 func (c *Component) widgetGraphHandlerFunc(gc *gin.Context) {
 	ctx := c.t.Context(gc.Request.Context())
 
-	points, err := strconv.ParseUint(gc.DefaultQuery("points", "200"), 10, 16)
-	if err != nil {
-		gc.JSON(http.StatusBadRequest, gin.H{"message": "Invalid value for points."})
+	var params widgetParameters
+	if err := gc.ShouldBindQuery(&params); err != nil {
+		gc.JSON(http.StatusBadRequest, gin.H{"message": helpers.Capitalize(err.Error())})
 		return
 	}
-	if points < 5 || points > 1000 {
-		gc.JSON(http.StatusBadRequest, gin.H{"message": "Points should be > 5 and < 1000"})
-		return
+	if params.Points == 0 {
+		params.Points = 200
 	}
-	interval := int64((24 * time.Hour).Seconds()) / int64(points)
+	interval := int64((24 * time.Hour).Seconds()) / int64(params.Points)
 	now := c.d.Clock.Now()
 	query := c.queryFlowsTable(fmt.Sprintf(`
 WITH
@@ -200,7 +204,7 @@ ORDER BY Time`, interval), now.Add(-24*time.Hour), now, time.Duration(interval)*
 		Time time.Time `json:"t"`
 		Gbps float64   `json:"gbps"`
 	}{}
-	err = c.d.ClickHouseDB.Conn.Select(ctx, &results, query)
+	err := c.d.ClickHouseDB.Conn.Select(ctx, &results, query)
 	if err != nil {
 		c.r.Err(err).Msg("unable to query database")
 		gc.JSON(http.StatusInternalServerError, gin.H{"message": "Unable to query database."})
diff --git a/inlet/core/http.go b/inlet/core/http.go
index 359c542a..3c7139c9 100644
--- a/inlet/core/http.go
+++ b/inlet/core/http.go
@@ -5,6 +5,8 @@ import (
 	"sync/atomic"
 	"time"
 
+	"akvorado/common/helpers"
+
 	"github.com/gin-gonic/gin"
 )
 
@@ -17,9 +19,10 @@ type flowsParameters struct {
 // is intended for debug only.
 func (c *Component) FlowsHTTPHandler(gc *gin.Context) {
 	var params flowsParameters
-	var limit, count uint64
-	if gc.ShouldBindQuery(&params) == nil {
-		limit = params.Limit
+	var count uint64
+	if err := gc.ShouldBindQuery(&params); err != nil {
+		gc.JSON(http.StatusBadRequest, gin.H{"message": helpers.Capitalize(err.Error())})
+		return
 	}
 
 	atomic.AddUint32(&c.httpFlowClients, 1)
@@ -36,14 +39,14 @@ func (c *Component) FlowsHTTPHandler(gc *gin.Context) {
 		case <-gc.Request.Context().Done():
 			return
 		case msg := <-c.httpFlowChannel:
-			if limit == 1 {
+			if params.Limit == 1 {
 				gc.IndentedJSON(http.StatusOK, msg)
 			} else {
 				gc.JSON(http.StatusOK, msg)
 				gc.Writer.Write([]byte("\n"))
 			}
 			count++
-			if limit > 0 && count == limit {
+			if params.Limit > 0 && count == params.Limit {
 				return
 			}
 		case <-tickerChan: