diff --git a/base/api.go b/base/api.go
index 04ff712..c4f03e3 100644
--- a/base/api.go
+++ b/base/api.go
@@ -3,11 +3,11 @@ package base
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
+	"strconv"
 	"strings"
 	"time"
-	"strconv"
 )
 
 // Exec execute a WarpScript on the backend, returning resultat as byte array
@@ -25,10 +25,19 @@ func (c *Client) Exec(warpScript string) ([]byte, error) {
 	}
 
 	if res.StatusCode != http.StatusOK {
-		return nil, errors.New(res.Header.Get(HeaderErrorMessage))
+
+		if h := res.Header.Get(HeaderErrorMessage); h != "" {
+			return nil, errors.New(h)
+		}
+
+		if body, err := io.ReadAll(res.Body); err == nil {
+			return nil, errors.New(string(body))
+		}
+
+		return nil, fmt.Errorf("received status code '%s'", res.Status)
 	}
 
-	bts, err := ioutil.ReadAll(res.Body)
+	bts, err := io.ReadAll(res.Body)
 	if err != nil {
 		return nil, err
 	}
@@ -59,7 +68,7 @@ func (c *Client) Find(selector Selector) ([]byte, error) {
 		return nil, err
 	}
 
-	bts, err := ioutil.ReadAll(res.Body)
+	bts, err := io.ReadAll(res.Body)
 	if err != nil {
 		return nil, err
 	}
@@ -90,7 +99,7 @@ func (c *Client) Update(gts GTSList) error {
 		return err
 	}
 
-	bts, err := ioutil.ReadAll(res.Body)
+	bts, err := io.ReadAll(res.Body)
 	if err != nil {
 		return err
 	}
@@ -122,13 +131,13 @@ func (c *Client) Meta(gtsList GTSList) ([]byte, error) {
 		return nil, err
 	}
 
-	bts, err := ioutil.ReadAll(res.Body)
+	bts, err := io.ReadAll(res.Body)
 	if err != nil {
 		return nil, err
 	}
 
 	if res.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("Headers: %+v\nBody: %+v", res.Header, string(bts))
+		return nil, fmt.Errorf("headers: %+v\nBody: %+v", res.Header, string(bts))
 	}
 
 	return nil, res.Body.Close()
@@ -159,7 +168,7 @@ func (c *Client) Fetch(selector Selector, start time.Time, stop time.Time) ([]by
 		return nil, err
 	}
 
-	bts, err := ioutil.ReadAll(res.Body)
+	bts, err := io.ReadAll(res.Body)
 	if err != nil {
 		return nil, err
 	}
@@ -205,7 +214,7 @@ func (c *Client) Delete(selector Selector, start time.Time, stop time.Time) ([]b
 		return nil, err
 	}
 
-	bts, err := ioutil.ReadAll(res.Body)
+	bts, err := io.ReadAll(res.Body)
 	if err != nil {
 		return nil, err
 	}
diff --git a/base/errors.go b/base/errors.go
index 870084a..012b46f 100644
--- a/base/errors.go
+++ b/base/errors.go
@@ -3,6 +3,6 @@ package base
 import "errors"
 
 var (
-	NoReadTokenError  = errors.New("This Warp10 call need a READ token access on the data")
-	NoWriteTokenError = errors.New("This Warp10 call need a WRITE token access on the data")
-)
\ No newline at end of file
+	NoReadTokenError  = errors.New("this Warp10 call need a READ token access on the data")
+	NoWriteTokenError = errors.New("this Warp10 call need a WRITE token access on the data")
+)
diff --git a/base/gts-helper.go b/base/gts-helper.go
index 492fd49..696dd85 100644
--- a/base/gts-helper.go
+++ b/base/gts-helper.go
@@ -100,24 +100,24 @@ func parseSensisionLine(in string) (int64, float64, float64, float64, string, La
 
 	ctx := strings.Split(g[0], "/")
 	if len(ctx) != 3 {
-		err = errors.New("Cannot parse datapoint: " + in)
+		err = errors.New("cannot parse datapoint: " + in)
 		return ts, lat, long, alt, c, l, a, v, err
 	}
 
 	if ctx[0] == "" {
-		err = errors.New("No timestamp provided")
+		err = errors.New("no timestamp provided")
 		return ts, lat, long, alt, c, l, a, v, err
 	}
 	ts, err = strconv.ParseInt(ctx[0], 10, 64)
 	if err != nil {
-		err = errors.New("Cannot parse " + ctx[0] + " as valid timestamp")
+		err = errors.New("cannot parse " + ctx[0] + " as valid timestamp")
 		return ts, lat, long, alt, c, l, a, v, err
 	}
 
 	if ctx[2] != "" {
 		alt, err = strconv.ParseFloat(ctx[2], 64)
 		if err != nil {
-			err = errors.New("Cannot parse " + ctx[0] + " as valid altitude")
+			err = errors.New("cannot parse " + ctx[0] + " as valid altitude")
 			return ts, lat, long, alt, c, l, a, v, err
 		}
 	}
@@ -125,19 +125,19 @@ func parseSensisionLine(in string) (int64, float64, float64, float64, string, La
 	if ctx[1] != "" {
 		latlong := strings.Split(ctx[1], ":")
 		if len(latlong) != 2 {
-			err = errors.New("Cannot parse " + ctx[1] + " as valid latitude:longitude")
+			err = errors.New("cannot parse " + ctx[1] + " as valid latitude:longitude")
 			return ts, lat, long, alt, c, l, a, v, err
 		}
 
 		lat, err = strconv.ParseFloat(latlong[0], 64)
 		if err != nil {
-			err = errors.New("Cannot parse " + ctx[0] + " as valid latitude")
+			err = errors.New("cannot parse " + ctx[0] + " as valid latitude")
 			return ts, lat, long, alt, c, l, a, v, err
 		}
 
 		long, err = strconv.ParseFloat(latlong[1], 64)
 		if err != nil {
-			err = errors.New("Cannot parse " + ctx[0] + " as valid latitude")
+			err = errors.New("cannot parse " + ctx[0] + " as valid latitude")
 			return ts, lat, long, alt, c, l, a, v, err
 		}
 	}
@@ -149,7 +149,7 @@ func parseSensisionLine(in string) (int64, float64, float64, float64, string, La
 	// test }
 	//fmt.Println(fmt.Sprintf("%+v", classLabelsAttributes))
 	if len(classLabelsAttributes) != 2 {
-		err = errors.New("Cannot parse " + g[1] + " as valid class + labels + attributes")
+		err = errors.New("cannot parse " + g[1] + " as valid class + labels + attributes")
 		return ts, lat, long, alt, c, l, a, v, err
 	}
 
@@ -168,7 +168,7 @@ func parseSensisionLine(in string) (int64, float64, float64, float64, string, La
 		for _, labelPair := range labelsValue {
 			keyVal := strings.Split(labelPair, "=")
 			if len(keyVal) != 2 {
-				err = errors.New("Cannot parse " + labelPair + " as valid key and value label")
+				err = errors.New("cannot parse " + labelPair + " as valid key and value label")
 				return ts, lat, long, alt, c, l, a, v, err
 			}
 			l[keyVal[0]] = keyVal[1]
@@ -179,7 +179,7 @@ func parseSensisionLine(in string) (int64, float64, float64, float64, string, La
 	vStr = strings.Trim(vStr, "'")
 
 	if len(vStr) == 0 {
-		err = errors.New("Cannot parse " + strings.Join(g[2:], " ") + " as valid value")
+		err = errors.New("cannot parse " + strings.Join(g[2:], " ") + " as valid value")
 		return ts, lat, long, alt, c, l, a, v, err
 	}