diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 0000000..4ae0279
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,49 @@
+# golangci-lint configuration
+
+run:
+  skip-dirs:
+    - build
+    - examples
+
+  timeout: 10m
+
+issues:
+
+linters:
+  enable:
+    - asciicheck  # check for non-ascii characters
+    - errorlint   # enure error wrapping is safely done
+    - gocritic    # check for certain simplifications
+    - gofmt       # ensure code is formatted
+    - gosec       # check for security concerns
+    - nilerr      # ensure errors aren't mishandled
+    - staticcheck # check for suspicious constructs
+    - unused      # check for unused constructs
+
+linters-settings:
+  errcheck:
+    # report when type assertions aren't checked for errors as in
+    #         a := b.(MyStruct)
+    #
+    check-type-assertions: true
+
+  gocritic:
+    disabled-tags:
+      - experimental
+      - opinionated
+
+    disabled-checks:
+      - ifElseChain
+      - assignOp
+      - unlambda
+      - exitAfterDefer
+
+  gosec:
+    excludes:
+      - G404  # checks that random numbers are securely generated
+
+  govet:
+    enable-all: true
+    disable:
+      - shadow
+      - fieldalignment
diff --git a/api/http_api.go b/api/http_api.go
index 4067a54..5220f93 100644
--- a/api/http_api.go
+++ b/api/http_api.go
@@ -96,6 +96,9 @@ func (api *HttpApi) putFileHandler(ctx *fiber.Ctx) error {
 		return api.writeErrResponse(ctx, http.StatusBadRequest, errors.New("got content length < 2"))
 	}
 	f, err := fileHeader.Open()
+	if err != nil {
+		return err
+	}
 	defer f.Close()
 
 	cmd := &engine.PutFileCmd{}
@@ -121,20 +124,21 @@ func (api *HttpApi) downloadFileHandler(ctx *fiber.Ctx) error {
 		return api.writeErrResponse(ctx, http.StatusBadRequest, errors.New("invalid request"))
 	}
 	_, buff, err := api.engine.DownloadFile(fId)
-
+	if err != nil {
+		return err
+	}
 	zr := lz4.NewReader(buff)
 	if err := zr.Apply(lz4.ConcurrencyOption(4)); err != nil {
 		return err
 	}
 
-	ctx.SendStream(zr)
-	return err
+	return ctx.SendStream(zr)
 }
 
 // TODO For browsers use attachment+file name
-func (api *HttpApi) downloadFileAttachHandler(ctx *fiber.Ctx) error {
-	return nil
-}
+// func (api *HttpApi) downloadFileAttachHandler(ctx *fiber.Ctx) error {
+//	return nil
+// }
 
 func (api *HttpApi) getFileMetadata(ctx *fiber.Ctx) error {
 	fIdParam := ctx.Params("fId")
diff --git a/build.sh b/build.sh
index bfa6fd2..34ee6d5 100644
--- a/build.sh
+++ b/build.sh
@@ -1,3 +1,5 @@
+golangci-lint run
+
 go build -ldflags "-s -w" -o build/mosaic
 #env GOOS=windows GOARCH=amd64 go build -ldflags "-s -w" -o build/mosaic.exe
 #env GOOS=darwin GOARCH=amd64 go build -ldflags "-s -w" -o build/mosaic-darwin
diff --git a/engine/cmd_put_file.go b/engine/cmd_put_file.go
index 5afac3c..fc0deed 100644
--- a/engine/cmd_put_file.go
+++ b/engine/cmd_put_file.go
@@ -70,6 +70,9 @@ func (cmd *PutFileCmd) Prepare(engine *Engine) error {
 
 	// check if file already uploaded
 	checkMeta, err := cmd.engine.db.GetFileMetadataById(fileHash)
+	if err != nil {
+		return err
+	}
 	if checkMeta != nil {
 		cmd.FileMetadata = checkMeta
 		slog.Info("File already exists", "fId", fileHash.String(), "oSize", checkMeta.OriginalFileSize)
diff --git a/engine/cmd_upload_err.go b/engine/cmd_upload_err.go
index 6b05025..7e4a50f 100644
--- a/engine/cmd_upload_err.go
+++ b/engine/cmd_upload_err.go
@@ -17,7 +17,9 @@ func (cmd *FileUploadErrCmd) Execute() error {
 	err := cmd.Err
 	slog.Info("Try resolve upload err", "fId", fileMeta.Id.String(), "err", err.Error())
 	// decrease used space by file
-	cmd.engine.db.UpdateShardsSize(fileMeta.UsedSpace(), false)
+	if err := cmd.engine.db.UpdateShardsSize(fileMeta.UsedSpace(), false); err != nil {
+		return err
+	}
 	// async free resources on shards
 	go func() {
 		for _, chunk := range fileMeta.Chunks {
diff --git a/engine/engine_test.go b/engine/engine_test.go
index 08a630e..987ab58 100644
--- a/engine/engine_test.go
+++ b/engine/engine_test.go
@@ -42,16 +42,6 @@ func buildShardState() map[types.ShardId]uint64 {
 	return shards
 }
 
-func buildShardState2() map[types.ShardId]uint64 {
-	shards := map[types.ShardId]uint64{
-		1: 10,
-		2: 8,
-		3: 12,
-		4: 11,
-	}
-	return shards
-}
-
 func buildShardState3() map[types.ShardId]uint64 {
 	shards := map[types.ShardId]uint64{
 		1: 10,
diff --git a/engine/file_downloader_test.go b/engine/file_downloader_test.go
index be081c4..1b1e0d9 100644
--- a/engine/file_downloader_test.go
+++ b/engine/file_downloader_test.go
@@ -2,6 +2,7 @@ package engine
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"github.com/pierrec/lz4/v4"
 	"io"
@@ -17,7 +18,7 @@ import (
 func TestFileUploader(t *testing.T) {
 	database := mosaicdb.NewDatabase("")
 	storage := storage.NewStorage()
-	engine, err := NewEngine("/tmp/masaic/temp", database, storage, 10)
+	engine, err := NewEngine(context.Background(), "/tmp/masaic/temp", database, storage, 10)
 	if err != nil {
 		panic(err)
 	}
diff --git a/mosaicdb/db.go b/mosaicdb/db.go
index 4452da6..749b8f4 100644
--- a/mosaicdb/db.go
+++ b/mosaicdb/db.go
@@ -33,9 +33,9 @@ func NewDatabase(dbPath string) *Database {
 		slog.Info("Initialize db", "path", dbPath)
 		os.MkdirAll(dbPath, 0774)
 		db, err = pebble.Open(dbPath, &pebble.Options{})
-		if err != nil {
-			panic(err)
-		}
+	}
+	if err != nil {
+		panic(err)
 	}
 	return &Database{
 		db: db,
diff --git a/utils/utils.go b/utils/utils.go
index e13a979..703bb92 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -33,7 +33,9 @@ func RandomString(count int) string {
 
 func RandomBytes(count int) []byte {
 	buf := make([]byte, count)
-	cp.Read(buf)
+	if _, err := cp.Read(buf); err != nil {
+		panic(err)
+	}
 	return buf
 }
 
@@ -81,6 +83,8 @@ func Btou32(val []byte) uint32 {
 
 func HashFrom(data []byte) types.H256 {
 	hasher := blake3.New()
-	hasher.Write(data)
+	if _, err := hasher.Write(data); err != nil {
+		panic(err)
+	}
 	return hasher.Sum(nil)
 }