diff --git a/api/auth/center.go b/api/auth/center.go
index 4b809ef..5b27e64 100644
--- a/api/auth/center.go
+++ b/api/auth/center.go
@@ -14,7 +14,7 @@ import (
 	"time"
 
 	v4 "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/auth/signer/v4"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/tokens"
@@ -94,12 +94,12 @@ func New(creds tokens.Credentials, prefixes []string) *Center {
 func (c *Center) parseAuthHeader(header string) (*AuthHeader, error) {
 	submatches := c.reg.GetSubmatches(header)
 	if len(submatches) != authHeaderPartsNum {
-		return nil, fmt.Errorf("%w: %s", apiErrors.GetAPIError(apiErrors.ErrAuthorizationHeaderMalformed), header)
+		return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrAuthorizationHeaderMalformed), header)
 	}
 
 	accessKey := strings.Split(submatches["access_key_id"], "0")
 	if len(accessKey) != accessKeyPartsNum {
-		return nil, fmt.Errorf("%w: %s", apiErrors.GetAPIError(apiErrors.ErrInvalidAccessKeyID), accessKey)
+		return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrInvalidAccessKeyID), accessKey)
 	}
 
 	signedFields := strings.Split(submatches["signed_header_fields"], ";")
@@ -117,7 +117,7 @@ func (c *Center) parseAuthHeader(header string) (*AuthHeader, error) {
 func getAddress(accessKeyID string) (oid.Address, error) {
 	var addr oid.Address
 	if err := addr.DecodeString(strings.ReplaceAll(accessKeyID, "0", "/")); err != nil {
-		return addr, fmt.Errorf("%w: %s", apiErrors.GetAPIError(apiErrors.ErrInvalidAccessKeyID), accessKeyID)
+		return addr, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrInvalidAccessKeyID), accessKeyID)
 	}
 
 	return addr, nil
@@ -220,11 +220,11 @@ func checkFormatHashContentSHA256(hash string) error {
 	if !IsStandardContentSHA256(hash) {
 		hashBinary, err := hex.DecodeString(hash)
 		if err != nil {
-			return fmt.Errorf("%w: decode hash: %s: %s", apiErrors.GetAPIError(apiErrors.ErrContentSHA256Mismatch),
+			return fmt.Errorf("%w: decode hash: %s: %s", apierr.GetAPIError(apierr.ErrContentSHA256Mismatch),
 				hash, err.Error())
 		}
 		if len(hashBinary) != sha256.Size && len(hash) != 0 {
-			return fmt.Errorf("%w: invalid hash size %d", apiErrors.GetAPIError(apiErrors.ErrContentSHA256Mismatch), len(hashBinary))
+			return fmt.Errorf("%w: invalid hash size %d", apierr.GetAPIError(apierr.ErrContentSHA256Mismatch), len(hashBinary))
 		}
 	}
 
@@ -242,12 +242,12 @@ func (c Center) checkAccessKeyID(accessKeyID string) error {
 		}
 	}
 
-	return fmt.Errorf("%w: accesskeyID prefix isn't allowed", apiErrors.GetAPIError(apiErrors.ErrAccessDenied))
+	return fmt.Errorf("%w: accesskeyID prefix isn't allowed", apierr.GetAPIError(apierr.ErrAccessDenied))
 }
 
 func (c *Center) checkFormData(r *http.Request) (*middleware.Box, error) {
 	if err := r.ParseMultipartForm(maxFormSizeMemory); err != nil {
-		return nil, fmt.Errorf("%w: parse multipart form with max size %d", apiErrors.GetAPIError(apiErrors.ErrInvalidArgument), maxFormSizeMemory)
+		return nil, fmt.Errorf("%w: parse multipart form with max size %d", apierr.GetAPIError(apierr.ErrInvalidArgument), maxFormSizeMemory)
 	}
 
 	if err := prepareForm(r.MultipartForm); err != nil {
@@ -262,7 +262,7 @@ func (c *Center) checkFormData(r *http.Request) (*middleware.Box, error) {
 	creds := MultipartFormValue(r, "x-amz-credential")
 	submatches := c.postReg.GetSubmatches(creds)
 	if len(submatches) != 4 {
-		return nil, fmt.Errorf("%w: %s", apiErrors.GetAPIError(apiErrors.ErrAuthorizationHeaderMalformed), creds)
+		return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrAuthorizationHeaderMalformed), creds)
 	}
 
 	signatureDateTime, err := time.Parse("20060102T150405Z", MultipartFormValue(r, "x-amz-date"))
@@ -288,7 +288,7 @@ func (c *Center) checkFormData(r *http.Request) (*middleware.Box, error) {
 	signature := SignStr(secret, service, region, signatureDateTime, policy)
 	reqSignature := MultipartFormValue(r, "x-amz-signature")
 	if signature != reqSignature {
-		return nil, fmt.Errorf("%w: %s != %s", apiErrors.GetAPIError(apiErrors.ErrSignatureDoesNotMatch),
+		return nil, fmt.Errorf("%w: %s != %s", apierr.GetAPIError(apierr.ErrSignatureDoesNotMatch),
 			reqSignature, signature)
 	}
 
@@ -333,11 +333,11 @@ func (c *Center) checkSign(authHeader *AuthHeader, box *accessbox.Box, request *
 	if authHeader.IsPresigned {
 		now := time.Now()
 		if signatureDateTime.Add(authHeader.Expiration).Before(now) {
-			return fmt.Errorf("%w: expired: now %s, signature %s", apiErrors.GetAPIError(apiErrors.ErrExpiredPresignRequest),
+			return fmt.Errorf("%w: expired: now %s, signature %s", apierr.GetAPIError(apierr.ErrExpiredPresignRequest),
 				now.Format(time.RFC3339), signatureDateTime.Format(time.RFC3339))
 		}
 		if now.Before(signatureDateTime) {
-			return fmt.Errorf("%w: signature time from the future: now %s, signature %s", apiErrors.GetAPIError(apiErrors.ErrBadRequest),
+			return fmt.Errorf("%w: signature time from the future: now %s, signature %s", apierr.GetAPIError(apierr.ErrBadRequest),
 				now.Format(time.RFC3339), signatureDateTime.Format(time.RFC3339))
 		}
 		if _, err := signer.Presign(request, nil, authHeader.Service, authHeader.Region, authHeader.Expiration, signatureDateTime); err != nil {
@@ -352,7 +352,7 @@ func (c *Center) checkSign(authHeader *AuthHeader, box *accessbox.Box, request *
 	}
 
 	if authHeader.SignatureV4 != signature {
-		return fmt.Errorf("%w: %s != %s: headers %v", apiErrors.GetAPIError(apiErrors.ErrSignatureDoesNotMatch),
+		return fmt.Errorf("%w: %s != %s: headers %v", apierr.GetAPIError(apierr.ErrSignatureDoesNotMatch),
 			authHeader.SignatureV4, signature, authHeader.SignedFields)
 	}
 
diff --git a/api/auth/center_test.go b/api/auth/center_test.go
index 23235eb..8066dc8 100644
--- a/api/auth/center_test.go
+++ b/api/auth/center_test.go
@@ -17,7 +17,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/tokens"
-	frostfsErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
+	frosterr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
@@ -419,7 +419,7 @@ func TestAuthenticate(t *testing.T) {
 			if tc.err {
 				require.Error(t, err)
 				if tc.errCode > 0 {
-					err = frostfsErrors.UnwrapErr(err)
+					err = frosterr.UnwrapErr(err)
 					require.Equal(t, errors.GetAPIError(tc.errCode), err)
 				}
 			} else {
@@ -596,7 +596,7 @@ func TestHTTPPostAuthenticate(t *testing.T) {
 			if tc.err {
 				require.Error(t, err)
 				if tc.errCode > 0 {
-					err = frostfsErrors.UnwrapErr(err)
+					err = frosterr.UnwrapErr(err)
 					require.Equal(t, errors.GetAPIError(tc.errCode), err)
 				}
 			} else {
diff --git a/api/handler/acl_test.go b/api/handler/acl_test.go
index fb1c46b..8bb6a06 100644
--- a/api/handler/acl_test.go
+++ b/api/handler/acl_test.go
@@ -11,7 +11,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
@@ -28,12 +28,12 @@ func TestPutObjectACLErrorAPE(t *testing.T) {
 
 	info := createBucket(hc, bktName)
 
-	putObjectWithHeadersAssertS3Error(hc, bktName, objName, map[string]string{api.AmzACL: basicACLPublic}, s3errors.ErrAccessControlListNotSupported)
+	putObjectWithHeadersAssertS3Error(hc, bktName, objName, map[string]string{api.AmzACL: basicACLPublic}, apierr.ErrAccessControlListNotSupported)
 	putObjectWithHeaders(hc, bktName, objName, map[string]string{api.AmzACL: basicACLPrivate}) // only `private` canned acl is allowed, that is actually ignored
 	putObjectWithHeaders(hc, bktName, objName, nil)
 
 	aclBody := &AccessControlPolicy{}
-	putObjectACLAssertS3Error(hc, bktName, objName, info.Box, nil, aclBody, s3errors.ErrAccessControlListNotSupported)
+	putObjectACLAssertS3Error(hc, bktName, objName, info.Box, nil, aclBody, apierr.ErrAccessControlListNotSupported)
 
 	aclRes := getObjectACL(hc, bktName, objName)
 	checkPrivateACL(t, aclRes, info.Key.PublicKey())
@@ -49,7 +49,7 @@ func TestCreateObjectACLErrorAPE(t *testing.T) {
 	copyObject(hc, bktName, objName, objNameCopy, CopyMeta{Headers: map[string]string{api.AmzACL: basicACLPublic}}, http.StatusBadRequest)
 	copyObject(hc, bktName, objName, objNameCopy, CopyMeta{Headers: map[string]string{api.AmzACL: basicACLPrivate}}, http.StatusOK)
 
-	createMultipartUploadAssertS3Error(hc, bktName, objName, map[string]string{api.AmzACL: basicACLPublic}, s3errors.ErrAccessControlListNotSupported)
+	createMultipartUploadAssertS3Error(hc, bktName, objName, map[string]string{api.AmzACL: basicACLPublic}, apierr.ErrAccessControlListNotSupported)
 	createMultipartUpload(hc, bktName, objName, map[string]string{api.AmzACL: basicACLPrivate})
 }
 
@@ -60,7 +60,7 @@ func TestBucketACLAPE(t *testing.T) {
 	info := createBucket(hc, bktName)
 
 	aclBody := &AccessControlPolicy{}
-	putBucketACLAssertS3Error(hc, bktName, info.Box, nil, aclBody, s3errors.ErrAccessControlListNotSupported)
+	putBucketACLAssertS3Error(hc, bktName, info.Box, nil, aclBody, apierr.ErrAccessControlListNotSupported)
 
 	aclRes := getBucketACL(hc, bktName)
 	checkPrivateACL(t, aclRes, info.Key.PublicKey())
@@ -113,7 +113,7 @@ func TestBucketPolicy(t *testing.T) {
 
 	createTestBucket(hc, bktName)
 
-	getBucketPolicy(hc, bktName, s3errors.ErrNoSuchBucketPolicy)
+	getBucketPolicy(hc, bktName, apierr.ErrNoSuchBucketPolicy)
 
 	newPolicy := engineiam.Policy{
 		Version: "2012-10-17",
@@ -125,7 +125,7 @@ func TestBucketPolicy(t *testing.T) {
 		}},
 	}
 
-	putBucketPolicy(hc, bktName, newPolicy, s3errors.ErrMalformedPolicy)
+	putBucketPolicy(hc, bktName, newPolicy, apierr.ErrMalformedPolicy)
 
 	newPolicy.Statement[0].Resource[0] = arnAwsPrefix + bktName + "/*"
 	putBucketPolicy(hc, bktName, newPolicy)
@@ -140,7 +140,7 @@ func TestBucketPolicyStatus(t *testing.T) {
 
 	createTestBucket(hc, bktName)
 
-	getBucketPolicy(hc, bktName, s3errors.ErrNoSuchBucketPolicy)
+	getBucketPolicy(hc, bktName, apierr.ErrNoSuchBucketPolicy)
 
 	newPolicy := engineiam.Policy{
 		Version: "2012-10-17",
@@ -152,7 +152,7 @@ func TestBucketPolicyStatus(t *testing.T) {
 		}},
 	}
 
-	putBucketPolicy(hc, bktName, newPolicy, s3errors.ErrMalformedPolicyNotPrincipal)
+	putBucketPolicy(hc, bktName, newPolicy, apierr.ErrMalformedPolicyNotPrincipal)
 
 	newPolicy.Statement[0].NotPrincipal = nil
 	newPolicy.Statement[0].Principal = map[engineiam.PrincipalType][]string{engineiam.Wildcard: {}}
@@ -221,7 +221,7 @@ func TestPutBucketPolicy(t *testing.T) {
 	assertStatus(hc.t, w, http.StatusOK)
 }
 
-func getBucketPolicy(hc *handlerContext, bktName string, errCode ...s3errors.ErrorCode) engineiam.Policy {
+func getBucketPolicy(hc *handlerContext, bktName string, errCode ...apierr.ErrorCode) engineiam.Policy {
 	w, r := prepareTestRequest(hc, bktName, "", nil)
 	hc.Handler().GetBucketPolicyHandler(w, r)
 
@@ -231,13 +231,13 @@ func getBucketPolicy(hc *handlerContext, bktName string, errCode ...s3errors.Err
 		err := json.NewDecoder(w.Result().Body).Decode(&policy)
 		require.NoError(hc.t, err)
 	} else {
-		assertS3Error(hc.t, w, s3errors.GetAPIError(errCode[0]))
+		assertS3Error(hc.t, w, apierr.GetAPIError(errCode[0]))
 	}
 
 	return policy
 }
 
-func getBucketPolicyStatus(hc *handlerContext, bktName string, errCode ...s3errors.ErrorCode) PolicyStatus {
+func getBucketPolicyStatus(hc *handlerContext, bktName string, errCode ...apierr.ErrorCode) PolicyStatus {
 	w, r := prepareTestRequest(hc, bktName, "", nil)
 	hc.Handler().GetBucketPolicyStatusHandler(w, r)
 
@@ -247,13 +247,13 @@ func getBucketPolicyStatus(hc *handlerContext, bktName string, errCode ...s3erro
 		err := xml.NewDecoder(w.Result().Body).Decode(&policyStatus)
 		require.NoError(hc.t, err)
 	} else {
-		assertS3Error(hc.t, w, s3errors.GetAPIError(errCode[0]))
+		assertS3Error(hc.t, w, apierr.GetAPIError(errCode[0]))
 	}
 
 	return policyStatus
 }
 
-func putBucketPolicy(hc *handlerContext, bktName string, bktPolicy engineiam.Policy, errCode ...s3errors.ErrorCode) {
+func putBucketPolicy(hc *handlerContext, bktName string, bktPolicy engineiam.Policy, errCode ...apierr.ErrorCode) {
 	body, err := json.Marshal(bktPolicy)
 	require.NoError(hc.t, err)
 
@@ -263,7 +263,7 @@ func putBucketPolicy(hc *handlerContext, bktName string, bktPolicy engineiam.Pol
 	if len(errCode) == 0 {
 		assertStatus(hc.t, w, http.StatusOK)
 	} else {
-		assertS3Error(hc.t, w, s3errors.GetAPIError(errCode[0]))
+		assertS3Error(hc.t, w, apierr.GetAPIError(errCode[0]))
 	}
 }
 
@@ -312,9 +312,9 @@ func createBucket(hc *handlerContext, bktName string) *createBucketInfo {
 	}
 }
 
-func createBucketAssertS3Error(hc *handlerContext, bktName string, box *accessbox.Box, code s3errors.ErrorCode) {
+func createBucketAssertS3Error(hc *handlerContext, bktName string, box *accessbox.Box, code apierr.ErrorCode) {
 	w := createBucketBase(hc, bktName, box)
-	assertS3Error(hc.t, w, s3errors.GetAPIError(code))
+	assertS3Error(hc.t, w, apierr.GetAPIError(code))
 }
 
 func createBucketBase(hc *handlerContext, bktName string, box *accessbox.Box) *httptest.ResponseRecorder {
@@ -330,9 +330,9 @@ func putBucketACL(hc *handlerContext, bktName string, box *accessbox.Box, header
 	assertStatus(hc.t, w, http.StatusOK)
 }
 
-func putBucketACLAssertS3Error(hc *handlerContext, bktName string, box *accessbox.Box, header map[string]string, body *AccessControlPolicy, code s3errors.ErrorCode) {
+func putBucketACLAssertS3Error(hc *handlerContext, bktName string, box *accessbox.Box, header map[string]string, body *AccessControlPolicy, code apierr.ErrorCode) {
 	w := putBucketACLBase(hc, bktName, box, header, body)
-	assertS3Error(hc.t, w, s3errors.GetAPIError(code))
+	assertS3Error(hc.t, w, apierr.GetAPIError(code))
 }
 
 func putBucketACLBase(hc *handlerContext, bktName string, box *accessbox.Box, header map[string]string, body *AccessControlPolicy) *httptest.ResponseRecorder {
@@ -360,9 +360,9 @@ func getBucketACLBase(hc *handlerContext, bktName string) *httptest.ResponseReco
 	return w
 }
 
-func putObjectACLAssertS3Error(hc *handlerContext, bktName, objName string, box *accessbox.Box, header map[string]string, body *AccessControlPolicy, code s3errors.ErrorCode) {
+func putObjectACLAssertS3Error(hc *handlerContext, bktName, objName string, box *accessbox.Box, header map[string]string, body *AccessControlPolicy, code apierr.ErrorCode) {
 	w := putObjectACLBase(hc, bktName, objName, box, header, body)
-	assertS3Error(hc.t, w, s3errors.GetAPIError(code))
+	assertS3Error(hc.t, w, apierr.GetAPIError(code))
 }
 
 func putObjectACLBase(hc *handlerContext, bktName, objName string, box *accessbox.Box, header map[string]string, body *AccessControlPolicy) *httptest.ResponseRecorder {
@@ -396,9 +396,9 @@ func putObjectWithHeaders(hc *handlerContext, bktName, objName string, headers m
 	return w.Header()
 }
 
-func putObjectWithHeadersAssertS3Error(hc *handlerContext, bktName, objName string, headers map[string]string, code s3errors.ErrorCode) {
+func putObjectWithHeadersAssertS3Error(hc *handlerContext, bktName, objName string, headers map[string]string, code apierr.ErrorCode) {
 	w := putObjectWithHeadersBase(hc, bktName, objName, headers, nil, nil)
-	assertS3Error(hc.t, w, s3errors.GetAPIError(code))
+	assertS3Error(hc.t, w, apierr.GetAPIError(code))
 }
 
 func putObjectWithHeadersBase(hc *handlerContext, bktName, objName string, headers map[string]string, box *accessbox.Box, data []byte) *httptest.ResponseRecorder {
diff --git a/api/handler/delete_test.go b/api/handler/delete_test.go
index 2bf71e3..80d23c8 100644
--- a/api/handler/delete_test.go
+++ b/api/handler/delete_test.go
@@ -10,7 +10,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/encryption"
 	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
@@ -131,7 +131,7 @@ func TestDeleteObjectsError(t *testing.T) {
 	addr.SetContainer(bktInfo.CID)
 	addr.SetObject(nodeVersion.OID)
 
-	expectedError := apiErrors.GetAPIError(apiErrors.ErrAccessDenied)
+	expectedError := apierr.GetAPIError(apierr.ErrAccessDenied)
 	hc.tp.SetObjectError(addr, expectedError)
 
 	w := deleteObjectsBase(hc, bktName, [][2]string{{objName, nodeVersion.OID.EncodeToString()}})
@@ -553,9 +553,9 @@ func checkNotFound(t *testing.T, hc *handlerContext, bktName, objName, version s
 	assertStatus(t, w, http.StatusNotFound)
 }
 
-func headObjectAssertS3Error(hc *handlerContext, bktName, objName, version string, code apiErrors.ErrorCode) {
+func headObjectAssertS3Error(hc *handlerContext, bktName, objName, version string, code apierr.ErrorCode) {
 	w := headObjectBase(hc, bktName, objName, version)
-	assertS3Error(hc.t, w, apiErrors.GetAPIError(code))
+	assertS3Error(hc.t, w, apierr.GetAPIError(code))
 }
 
 func checkFound(t *testing.T, hc *handlerContext, bktName, objName, version string) {
diff --git a/api/handler/get_test.go b/api/handler/get_test.go
index e117f9d..30304e1 100644
--- a/api/handler/get_test.go
+++ b/api/handler/get_test.go
@@ -2,7 +2,7 @@ package handler
 
 import (
 	"bytes"
-	stderrors "errors"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -13,7 +13,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
 	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
 	"github.com/stretchr/testify/require"
@@ -89,7 +89,7 @@ func TestPreconditions(t *testing.T) {
 			name:     "IfMatch false",
 			info:     newInfo(etag, today),
 			args:     &conditionalArgs{IfMatch: etag2},
-			expected: errors.GetAPIError(errors.ErrPreconditionFailed)},
+			expected: apierr.GetAPIError(apierr.ErrPreconditionFailed)},
 		{
 			name:     "IfNoneMatch true",
 			info:     newInfo(etag, today),
@@ -99,7 +99,7 @@ func TestPreconditions(t *testing.T) {
 			name:     "IfNoneMatch false",
 			info:     newInfo(etag, today),
 			args:     &conditionalArgs{IfNoneMatch: etag},
-			expected: errors.GetAPIError(errors.ErrNotModified)},
+			expected: apierr.GetAPIError(apierr.ErrNotModified)},
 		{
 			name:     "IfModifiedSince true",
 			info:     newInfo(etag, today),
@@ -109,7 +109,7 @@ func TestPreconditions(t *testing.T) {
 			name:     "IfModifiedSince false",
 			info:     newInfo(etag, yesterday),
 			args:     &conditionalArgs{IfModifiedSince: &today},
-			expected: errors.GetAPIError(errors.ErrNotModified)},
+			expected: apierr.GetAPIError(apierr.ErrNotModified)},
 		{
 			name:     "IfUnmodifiedSince true",
 			info:     newInfo(etag, yesterday),
@@ -119,7 +119,7 @@ func TestPreconditions(t *testing.T) {
 			name:     "IfUnmodifiedSince false",
 			info:     newInfo(etag, today),
 			args:     &conditionalArgs{IfUnmodifiedSince: &yesterday},
-			expected: errors.GetAPIError(errors.ErrPreconditionFailed)},
+			expected: apierr.GetAPIError(apierr.ErrPreconditionFailed)},
 
 		{
 			name:     "IfMatch true, IfUnmodifiedSince false",
@@ -131,19 +131,19 @@ func TestPreconditions(t *testing.T) {
 			name:     "IfMatch false, IfUnmodifiedSince true",
 			info:     newInfo(etag, yesterday),
 			args:     &conditionalArgs{IfMatch: etag2, IfUnmodifiedSince: &today},
-			expected: errors.GetAPIError(errors.ErrPreconditionFailed),
+			expected: apierr.GetAPIError(apierr.ErrPreconditionFailed),
 		},
 		{
 			name:     "IfNoneMatch false, IfModifiedSince true",
 			info:     newInfo(etag, today),
 			args:     &conditionalArgs{IfNoneMatch: etag, IfModifiedSince: &yesterday},
-			expected: errors.GetAPIError(errors.ErrNotModified),
+			expected: apierr.GetAPIError(apierr.ErrNotModified),
 		},
 		{
 			name:     "IfNoneMatch true, IfModifiedSince false",
 			info:     newInfo(etag, yesterday),
 			args:     &conditionalArgs{IfNoneMatch: etag2, IfModifiedSince: &today},
-			expected: errors.GetAPIError(errors.ErrNotModified),
+			expected: apierr.GetAPIError(apierr.ErrNotModified),
 		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
@@ -151,7 +151,7 @@ func TestPreconditions(t *testing.T) {
 			if tc.expected == nil {
 				require.NoError(t, actual)
 			} else {
-				require.True(t, stderrors.Is(actual, tc.expected), tc.expected, actual)
+				require.True(t, errors.Is(actual, tc.expected), tc.expected, actual)
 			}
 		})
 	}
@@ -193,8 +193,8 @@ func TestGetObject(t *testing.T) {
 	hc.tp.SetObjectError(addr, &apistatus.ObjectNotFound{})
 	hc.tp.SetObjectError(objInfo.Address(), &apistatus.ObjectNotFound{})
 
-	getObjectAssertS3Error(hc, bktName, objName, objInfo.VersionID(), errors.ErrNoSuchVersion)
-	getObjectAssertS3Error(hc, bktName, objName, emptyVersion, errors.ErrNoSuchKey)
+	getObjectAssertS3Error(hc, bktName, objName, objInfo.VersionID(), apierr.ErrNoSuchVersion)
+	getObjectAssertS3Error(hc, bktName, objName, emptyVersion, apierr.ErrNoSuchKey)
 }
 
 func TestGetObjectEnabledMD5(t *testing.T) {
@@ -236,9 +236,9 @@ func getObjectVersion(tc *handlerContext, bktName, objName, version string) []by
 	return content
 }
 
-func getObjectAssertS3Error(hc *handlerContext, bktName, objName, version string, code errors.ErrorCode) {
+func getObjectAssertS3Error(hc *handlerContext, bktName, objName, version string, code apierr.ErrorCode) {
 	w := getObjectBaseResponse(hc, bktName, objName, version)
-	assertS3Error(hc.t, w, errors.GetAPIError(code))
+	assertS3Error(hc.t, w, apierr.GetAPIError(code))
 }
 
 func getObjectBaseResponse(hc *handlerContext, bktName, objName, version string) *httptest.ResponseRecorder {
diff --git a/api/handler/head_test.go b/api/handler/head_test.go
index 9f0c88f..47d7417 100644
--- a/api/handler/head_test.go
+++ b/api/handler/head_test.go
@@ -6,7 +6,7 @@ import (
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
 	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
@@ -95,8 +95,8 @@ func TestHeadObject(t *testing.T) {
 	hc.tp.SetObjectError(addr, &apistatus.ObjectNotFound{})
 	hc.tp.SetObjectError(objInfo.Address(), &apistatus.ObjectNotFound{})
 
-	headObjectAssertS3Error(hc, bktName, objName, objInfo.VersionID(), s3errors.ErrNoSuchVersion)
-	headObjectAssertS3Error(hc, bktName, objName, emptyVersion, s3errors.ErrNoSuchKey)
+	headObjectAssertS3Error(hc, bktName, objName, objInfo.VersionID(), apierr.ErrNoSuchVersion)
+	headObjectAssertS3Error(hc, bktName, objName, emptyVersion, apierr.ErrNoSuchKey)
 }
 
 func TestIsAvailableToResolve(t *testing.T) {
diff --git a/api/handler/lifecycle.go b/api/handler/lifecycle.go
index 624859d..93fe2cc 100644
--- a/api/handler/lifecycle.go
+++ b/api/handler/lifecycle.go
@@ -9,7 +9,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 )
@@ -52,7 +52,7 @@ func (h *handler) PutBucketLifecycleHandler(w http.ResponseWriter, r *http.Reque
 	// Content-Md5 is required and should be set
 	// https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutBucketLifecycleConfiguration.html
 	if _, ok := r.Header[api.ContentMD5]; !ok {
-		h.logAndSendError(w, "missing Content-MD5", reqInfo, apiErr.GetAPIError(apiErr.ErrMissingContentMD5))
+		h.logAndSendError(w, "missing Content-MD5", reqInfo, apierr.GetAPIError(apierr.ErrMissingContentMD5))
 		return
 	}
 
@@ -64,12 +64,12 @@ func (h *handler) PutBucketLifecycleHandler(w http.ResponseWriter, r *http.Reque
 
 	cfg := new(data.LifecycleConfiguration)
 	if err = h.cfg.NewXMLDecoder(tee).Decode(cfg); err != nil {
-		h.logAndSendError(w, "could not decode body", reqInfo, fmt.Errorf("%w: %s", apiErr.GetAPIError(apiErr.ErrMalformedXML), err.Error()))
+		h.logAndSendError(w, "could not decode body", reqInfo, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrMalformedXML), err.Error()))
 		return
 	}
 
 	if err = checkLifecycleConfiguration(cfg); err != nil {
-		h.logAndSendError(w, "invalid lifecycle configuration", reqInfo, fmt.Errorf("%w: %s", apiErr.GetAPIError(apiErr.ErrMalformedXML), err.Error()))
+		h.logAndSendError(w, "invalid lifecycle configuration", reqInfo, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrMalformedXML), err.Error()))
 		return
 	}
 
diff --git a/api/handler/lifecycle_test.go b/api/handler/lifecycle_test.go
index 9f48089..77aef64 100644
--- a/api/handler/lifecycle_test.go
+++ b/api/handler/lifecycle_test.go
@@ -14,7 +14,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"github.com/mr-tron/base58"
 	"github.com/stretchr/testify/require"
 )
@@ -340,7 +340,7 @@ func TestPutBucketLifecycleConfiguration(t *testing.T) {
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			if tc.error {
-				putBucketLifecycleConfigurationErr(hc, bktName, tc.body, apiErrors.GetAPIError(apiErrors.ErrMalformedXML))
+				putBucketLifecycleConfigurationErr(hc, bktName, tc.body, apierr.GetAPIError(apierr.ErrMalformedXML))
 				return
 			}
 
@@ -350,7 +350,7 @@ func TestPutBucketLifecycleConfiguration(t *testing.T) {
 			require.Equal(t, *tc.body, *cfg)
 
 			deleteBucketLifecycleConfiguration(hc, bktName)
-			getBucketLifecycleConfigurationErr(hc, bktName, apiErrors.GetAPIError(apiErrors.ErrNoSuchLifecycleConfiguration))
+			getBucketLifecycleConfigurationErr(hc, bktName, apierr.GetAPIError(apierr.ErrNoSuchLifecycleConfiguration))
 		})
 	}
 }
@@ -374,17 +374,17 @@ func TestPutBucketLifecycleInvalidMD5(t *testing.T) {
 
 	w, r := prepareTestRequest(hc, bktName, "", lifecycle)
 	hc.Handler().PutBucketLifecycleHandler(w, r)
-	assertS3Error(hc.t, w, apiErrors.GetAPIError(apiErrors.ErrMissingContentMD5))
+	assertS3Error(hc.t, w, apierr.GetAPIError(apierr.ErrMissingContentMD5))
 
 	w, r = prepareTestRequest(hc, bktName, "", lifecycle)
 	r.Header.Set(api.ContentMD5, "")
 	hc.Handler().PutBucketLifecycleHandler(w, r)
-	assertS3Error(hc.t, w, apiErrors.GetAPIError(apiErrors.ErrInvalidDigest))
+	assertS3Error(hc.t, w, apierr.GetAPIError(apierr.ErrInvalidDigest))
 
 	w, r = prepareTestRequest(hc, bktName, "", lifecycle)
 	r.Header.Set(api.ContentMD5, "some-hash")
 	hc.Handler().PutBucketLifecycleHandler(w, r)
-	assertS3Error(hc.t, w, apiErrors.GetAPIError(apiErrors.ErrInvalidDigest))
+	assertS3Error(hc.t, w, apierr.GetAPIError(apierr.ErrInvalidDigest))
 }
 
 func TestPutBucketLifecycleInvalidXML(t *testing.T) {
@@ -396,7 +396,7 @@ func TestPutBucketLifecycleInvalidXML(t *testing.T) {
 	w, r := prepareTestRequest(hc, bktName, "", &data.CORSConfiguration{})
 	r.Header.Set(api.ContentMD5, "")
 	hc.Handler().PutBucketLifecycleHandler(w, r)
-	assertS3Error(hc.t, w, apiErrors.GetAPIError(apiErrors.ErrMalformedXML))
+	assertS3Error(hc.t, w, apierr.GetAPIError(apierr.ErrMalformedXML))
 }
 
 func putBucketLifecycleConfiguration(hc *handlerContext, bktName string, cfg *data.LifecycleConfiguration) {
@@ -404,7 +404,7 @@ func putBucketLifecycleConfiguration(hc *handlerContext, bktName string, cfg *da
 	assertStatus(hc.t, w, http.StatusOK)
 }
 
-func putBucketLifecycleConfigurationErr(hc *handlerContext, bktName string, cfg *data.LifecycleConfiguration, err apiErrors.Error) {
+func putBucketLifecycleConfigurationErr(hc *handlerContext, bktName string, cfg *data.LifecycleConfiguration, err apierr.Error) {
 	w := putBucketLifecycleConfigurationBase(hc, bktName, cfg)
 	assertS3Error(hc.t, w, err)
 }
@@ -430,7 +430,7 @@ func getBucketLifecycleConfiguration(hc *handlerContext, bktName string) *data.L
 	return res
 }
 
-func getBucketLifecycleConfigurationErr(hc *handlerContext, bktName string, err apiErrors.Error) {
+func getBucketLifecycleConfigurationErr(hc *handlerContext, bktName string, err apierr.Error) {
 	w := getBucketLifecycleConfigurationBase(hc, bktName)
 	assertS3Error(hc.t, w, err)
 }
diff --git a/api/handler/locking.go b/api/handler/locking.go
index fa07774..f9dce14 100644
--- a/api/handler/locking.go
+++ b/api/handler/locking.go
@@ -9,7 +9,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 )
@@ -36,7 +36,7 @@ func (h *handler) PutBucketObjectLockConfigHandler(w http.ResponseWriter, r *htt
 
 	if !bktInfo.ObjectLockEnabled {
 		h.logAndSendError(w, "couldn't put object locking configuration", reqInfo,
-			apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotAllowed))
+			apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotAllowed))
 		return
 	}
 
@@ -83,7 +83,7 @@ func (h *handler) GetBucketObjectLockConfigHandler(w http.ResponseWriter, r *htt
 
 	if !bktInfo.ObjectLockEnabled {
 		h.logAndSendError(w, "object lock disabled", reqInfo,
-			apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotFound))
+			apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotFound))
 		return
 	}
 
@@ -116,7 +116,7 @@ func (h *handler) PutObjectLegalHoldHandler(w http.ResponseWriter, r *http.Reque
 
 	if !bktInfo.ObjectLockEnabled {
 		h.logAndSendError(w, "object lock disabled", reqInfo,
-			apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotFound))
+			apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotFound))
 		return
 	}
 
@@ -168,7 +168,7 @@ func (h *handler) GetObjectLegalHoldHandler(w http.ResponseWriter, r *http.Reque
 
 	if !bktInfo.ObjectLockEnabled {
 		h.logAndSendError(w, "object lock disabled", reqInfo,
-			apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotFound))
+			apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotFound))
 		return
 	}
 
@@ -204,7 +204,7 @@ func (h *handler) PutObjectRetentionHandler(w http.ResponseWriter, r *http.Reque
 	}
 	if !bktInfo.ObjectLockEnabled {
 		h.logAndSendError(w, "object lock disabled", reqInfo,
-			apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotFound))
+			apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotFound))
 		return
 	}
 
@@ -252,7 +252,7 @@ func (h *handler) GetObjectRetentionHandler(w http.ResponseWriter, r *http.Reque
 
 	if !bktInfo.ObjectLockEnabled {
 		h.logAndSendError(w, "object lock disabled", reqInfo,
-			apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotFound))
+			apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotFound))
 		return
 	}
 
@@ -269,7 +269,7 @@ func (h *handler) GetObjectRetentionHandler(w http.ResponseWriter, r *http.Reque
 	}
 
 	if !lockInfo.IsRetentionSet() {
-		h.logAndSendError(w, "retention lock isn't set", reqInfo, apiErrors.GetAPIError(apiErrors.ErrNoSuchKey))
+		h.logAndSendError(w, "retention lock isn't set", reqInfo, apierr.GetAPIError(apierr.ErrNoSuchKey))
 		return
 	}
 
@@ -314,7 +314,7 @@ func checkLockConfiguration(conf *data.ObjectLockConfiguration) error {
 func formObjectLock(ctx context.Context, bktInfo *data.BucketInfo, defaultConfig *data.ObjectLockConfiguration, header http.Header) (*data.ObjectLock, error) {
 	if !bktInfo.ObjectLockEnabled {
 		if existLockHeaders(header) {
-			return nil, apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotFound)
+			return nil, apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotFound)
 		}
 		return nil, nil
 	}
@@ -346,7 +346,7 @@ func formObjectLock(ctx context.Context, bktInfo *data.BucketInfo, defaultConfig
 	until := header.Get(api.AmzObjectLockRetainUntilDate)
 
 	if mode != "" && until == "" || mode == "" && until != "" {
-		return nil, apiErrors.GetAPIError(apiErrors.ErrObjectLockInvalidHeaders)
+		return nil, apierr.GetAPIError(apierr.ErrObjectLockInvalidHeaders)
 	}
 
 	if mode != "" {
@@ -355,7 +355,7 @@ func formObjectLock(ctx context.Context, bktInfo *data.BucketInfo, defaultConfig
 		}
 
 		if mode != complianceMode && mode != governanceMode {
-			return nil, apiErrors.GetAPIError(apiErrors.ErrUnknownWORMModeDirective)
+			return nil, apierr.GetAPIError(apierr.ErrUnknownWORMModeDirective)
 		}
 
 		objectLock.Retention.IsCompliance = mode == complianceMode
@@ -364,7 +364,7 @@ func formObjectLock(ctx context.Context, bktInfo *data.BucketInfo, defaultConfig
 	if until != "" {
 		retentionDate, err := time.Parse(time.RFC3339, until)
 		if err != nil {
-			return nil, apiErrors.GetAPIError(apiErrors.ErrInvalidRetentionDate)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidRetentionDate)
 		}
 		if objectLock.Retention == nil {
 			objectLock.Retention = &data.RetentionLock{}
@@ -382,7 +382,7 @@ func formObjectLock(ctx context.Context, bktInfo *data.BucketInfo, defaultConfig
 		}
 
 		if objectLock.Retention.Until.Before(layer.TimeNow(ctx)) {
-			return nil, apiErrors.GetAPIError(apiErrors.ErrPastObjectLockRetainDate)
+			return nil, apierr.GetAPIError(apierr.ErrPastObjectLockRetainDate)
 		}
 	}
 
@@ -397,16 +397,16 @@ func existLockHeaders(header http.Header) bool {
 
 func formObjectLockFromRetention(ctx context.Context, retention *data.Retention, header http.Header) (*data.ObjectLock, error) {
 	if retention.Mode != governanceMode && retention.Mode != complianceMode {
-		return nil, apiErrors.GetAPIError(apiErrors.ErrMalformedXML)
+		return nil, apierr.GetAPIError(apierr.ErrMalformedXML)
 	}
 
 	retentionDate, err := time.Parse(time.RFC3339, retention.RetainUntilDate)
 	if err != nil {
-		return nil, apiErrors.GetAPIError(apiErrors.ErrMalformedXML)
+		return nil, apierr.GetAPIError(apierr.ErrMalformedXML)
 	}
 
 	if retentionDate.Before(layer.TimeNow(ctx)) {
-		return nil, apiErrors.GetAPIError(apiErrors.ErrPastObjectLockRetainDate)
+		return nil, apierr.GetAPIError(apierr.ErrPastObjectLockRetainDate)
 	}
 
 	var bypass bool
diff --git a/api/handler/locking_test.go b/api/handler/locking_test.go
index 234e777..d2a8568 100644
--- a/api/handler/locking_test.go
+++ b/api/handler/locking_test.go
@@ -12,7 +12,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/encryption"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"github.com/stretchr/testify/require"
@@ -270,23 +270,23 @@ func TestPutBucketLockConfigurationHandler(t *testing.T) {
 	for _, tc := range []struct {
 		name          string
 		bucket        string
-		expectedError apiErrors.Error
+		expectedError apierr.Error
 		noError       bool
 		configuration *data.ObjectLockConfiguration
 	}{
 		{
 			name:          "bkt not found",
-			expectedError: apiErrors.GetAPIError(apiErrors.ErrNoSuchBucket),
+			expectedError: apierr.GetAPIError(apierr.ErrNoSuchBucket),
 		},
 		{
 			name:          "bkt lock disabled",
 			bucket:        bktLockDisabled,
-			expectedError: apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotAllowed),
+			expectedError: apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotAllowed),
 		},
 		{
 			name:          "invalid configuration",
 			bucket:        bktLockEnabled,
-			expectedError: apiErrors.GetAPIError(apiErrors.ErrInternalError),
+			expectedError: apierr.GetAPIError(apierr.ErrInternalError),
 			configuration: &data.ObjectLockConfiguration{ObjectLockEnabled: "dummy"},
 		},
 		{
@@ -359,18 +359,18 @@ func TestGetBucketLockConfigurationHandler(t *testing.T) {
 	for _, tc := range []struct {
 		name          string
 		bucket        string
-		expectedError apiErrors.Error
+		expectedError apierr.Error
 		noError       bool
 		expectedConf  *data.ObjectLockConfiguration
 	}{
 		{
 			name:          "bkt not found",
-			expectedError: apiErrors.GetAPIError(apiErrors.ErrNoSuchBucket),
+			expectedError: apierr.GetAPIError(apierr.ErrNoSuchBucket),
 		},
 		{
 			name:          "bkt lock disabled",
 			bucket:        bktLockDisabled,
-			expectedError: apiErrors.GetAPIError(apiErrors.ErrObjectLockConfigurationNotFound),
+			expectedError: apierr.GetAPIError(apierr.ErrObjectLockConfigurationNotFound),
 		},
 		{
 			name:         "bkt lock enabled empty default",
@@ -407,7 +407,7 @@ func TestGetBucketLockConfigurationHandler(t *testing.T) {
 	}
 }
 
-func assertS3Error(t *testing.T, w *httptest.ResponseRecorder, expectedError apiErrors.Error) {
+func assertS3Error(t *testing.T, w *httptest.ResponseRecorder, expectedError apierr.Error) {
 	actualErrorResponse := &middleware.ErrorResponse{}
 	err := xml.NewDecoder(w.Result().Body).Decode(actualErrorResponse)
 	require.NoError(t, err)
@@ -415,7 +415,7 @@ func assertS3Error(t *testing.T, w *httptest.ResponseRecorder, expectedError api
 	require.Equal(t, expectedError.HTTPStatusCode, w.Code)
 	require.Equal(t, expectedError.Code, actualErrorResponse.Code)
 
-	if expectedError.ErrCode != apiErrors.ErrInternalError {
+	if expectedError.ErrCode != apierr.ErrInternalError {
 		require.Equal(t, expectedError.Description, actualErrorResponse.Message)
 	}
 }
@@ -473,33 +473,33 @@ func TestObjectRetention(t *testing.T) {
 	objName := "obj-for-retention"
 	createTestObject(hc, bktInfo, objName, encryption.Params{})
 
-	getObjectRetention(hc, bktName, objName, nil, apiErrors.ErrNoSuchKey)
+	getObjectRetention(hc, bktName, objName, nil, apierr.ErrNoSuchKey)
 
 	retention := &data.Retention{Mode: governanceMode, RetainUntilDate: time.Now().Add(time.Minute).UTC().Format(time.RFC3339)}
 	putObjectRetention(hc, bktName, objName, retention, false, 0)
 	getObjectRetention(hc, bktName, objName, retention, 0)
 
 	retention = &data.Retention{Mode: governanceMode, RetainUntilDate: time.Now().UTC().Add(time.Minute).Format(time.RFC3339)}
-	putObjectRetention(hc, bktName, objName, retention, false, apiErrors.ErrInternalError)
+	putObjectRetention(hc, bktName, objName, retention, false, apierr.ErrInternalError)
 
 	retention = &data.Retention{Mode: complianceMode, RetainUntilDate: time.Now().Add(time.Minute).UTC().Format(time.RFC3339)}
 	putObjectRetention(hc, bktName, objName, retention, true, 0)
 	getObjectRetention(hc, bktName, objName, retention, 0)
 
-	putObjectRetention(hc, bktName, objName, retention, true, apiErrors.ErrInternalError)
+	putObjectRetention(hc, bktName, objName, retention, true, apierr.ErrInternalError)
 }
 
-func getObjectRetention(hc *handlerContext, bktName, objName string, retention *data.Retention, errCode apiErrors.ErrorCode) {
+func getObjectRetention(hc *handlerContext, bktName, objName string, retention *data.Retention, errCode apierr.ErrorCode) {
 	w, r := prepareTestRequest(hc, bktName, objName, nil)
 	hc.Handler().GetObjectRetentionHandler(w, r)
 	if errCode == 0 {
 		assertRetention(hc.t, w, retention)
 	} else {
-		assertS3Error(hc.t, w, apiErrors.GetAPIError(errCode))
+		assertS3Error(hc.t, w, apierr.GetAPIError(errCode))
 	}
 }
 
-func putObjectRetention(hc *handlerContext, bktName, objName string, retention *data.Retention, byPass bool, errCode apiErrors.ErrorCode) {
+func putObjectRetention(hc *handlerContext, bktName, objName string, retention *data.Retention, byPass bool, errCode apierr.ErrorCode) {
 	w, r := prepareTestRequest(hc, bktName, objName, retention)
 	if byPass {
 		r.Header.Set(api.AmzBypassGovernanceRetention, strconv.FormatBool(true))
@@ -508,7 +508,7 @@ func putObjectRetention(hc *handlerContext, bktName, objName string, retention *
 	if errCode == 0 {
 		assertStatus(hc.t, w, http.StatusOK)
 	} else {
-		assertS3Error(hc.t, w, apiErrors.GetAPIError(errCode))
+		assertS3Error(hc.t, w, apierr.GetAPIError(errCode))
 	}
 }
 
@@ -572,37 +572,37 @@ func TestPutLockErrors(t *testing.T) {
 	createTestBucketWithLock(hc, bktName, nil)
 
 	headers := map[string]string{api.AmzObjectLockMode: complianceMode}
-	putObjectWithLockFailed(t, hc, bktName, objName, headers, apiErrors.ErrObjectLockInvalidHeaders)
+	putObjectWithLockFailed(t, hc, bktName, objName, headers, apierr.ErrObjectLockInvalidHeaders)
 
 	delete(headers, api.AmzObjectLockMode)
 	headers[api.AmzObjectLockRetainUntilDate] = time.Now().Add(time.Minute).Format(time.RFC3339)
-	putObjectWithLockFailed(t, hc, bktName, objName, headers, apiErrors.ErrObjectLockInvalidHeaders)
+	putObjectWithLockFailed(t, hc, bktName, objName, headers, apierr.ErrObjectLockInvalidHeaders)
 
 	headers[api.AmzObjectLockMode] = "dummy"
-	putObjectWithLockFailed(t, hc, bktName, objName, headers, apiErrors.ErrUnknownWORMModeDirective)
+	putObjectWithLockFailed(t, hc, bktName, objName, headers, apierr.ErrUnknownWORMModeDirective)
 
 	headers[api.AmzObjectLockMode] = complianceMode
 	headers[api.AmzObjectLockRetainUntilDate] = time.Now().Format(time.RFC3339)
-	putObjectWithLockFailed(t, hc, bktName, objName, headers, apiErrors.ErrPastObjectLockRetainDate)
+	putObjectWithLockFailed(t, hc, bktName, objName, headers, apierr.ErrPastObjectLockRetainDate)
 
 	headers[api.AmzObjectLockRetainUntilDate] = "dummy"
-	putObjectWithLockFailed(t, hc, bktName, objName, headers, apiErrors.ErrInvalidRetentionDate)
+	putObjectWithLockFailed(t, hc, bktName, objName, headers, apierr.ErrInvalidRetentionDate)
 
 	putObject(hc, bktName, objName)
 
 	retention := &data.Retention{Mode: governanceMode}
-	putObjectRetentionFailed(t, hc, bktName, objName, retention, apiErrors.ErrMalformedXML)
+	putObjectRetentionFailed(t, hc, bktName, objName, retention, apierr.ErrMalformedXML)
 
 	retention.Mode = "dummy"
 	retention.RetainUntilDate = time.Now().Add(time.Minute).UTC().Format(time.RFC3339)
-	putObjectRetentionFailed(t, hc, bktName, objName, retention, apiErrors.ErrMalformedXML)
+	putObjectRetentionFailed(t, hc, bktName, objName, retention, apierr.ErrMalformedXML)
 
 	retention.Mode = governanceMode
 	retention.RetainUntilDate = time.Now().UTC().Format(time.RFC3339)
-	putObjectRetentionFailed(t, hc, bktName, objName, retention, apiErrors.ErrPastObjectLockRetainDate)
+	putObjectRetentionFailed(t, hc, bktName, objName, retention, apierr.ErrPastObjectLockRetainDate)
 }
 
-func putObjectWithLockFailed(t *testing.T, hc *handlerContext, bktName, objName string, headers map[string]string, errCode apiErrors.ErrorCode) {
+func putObjectWithLockFailed(t *testing.T, hc *handlerContext, bktName, objName string, headers map[string]string, errCode apierr.ErrorCode) {
 	w, r := prepareTestRequest(hc, bktName, objName, nil)
 
 	for key, val := range headers {
@@ -610,13 +610,13 @@ func putObjectWithLockFailed(t *testing.T, hc *handlerContext, bktName, objName
 	}
 
 	hc.Handler().PutObjectHandler(w, r)
-	assertS3Error(t, w, apiErrors.GetAPIError(errCode))
+	assertS3Error(t, w, apierr.GetAPIError(errCode))
 }
 
-func putObjectRetentionFailed(t *testing.T, hc *handlerContext, bktName, objName string, retention *data.Retention, errCode apiErrors.ErrorCode) {
+func putObjectRetentionFailed(t *testing.T, hc *handlerContext, bktName, objName string, retention *data.Retention, errCode apierr.ErrorCode) {
 	w, r := prepareTestRequest(hc, bktName, objName, retention)
 	hc.Handler().PutObjectRetentionHandler(w, r)
-	assertS3Error(t, w, apiErrors.GetAPIError(errCode))
+	assertS3Error(t, w, apierr.GetAPIError(errCode))
 }
 
 func assertRetentionApproximate(t *testing.T, w *httptest.ResponseRecorder, retention *data.Retention, delta float64) {
diff --git a/api/handler/multipart_upload_test.go b/api/handler/multipart_upload_test.go
index 4df0b10..ddfe905 100644
--- a/api/handler/multipart_upload_test.go
+++ b/api/handler/multipart_upload_test.go
@@ -15,7 +15,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3Errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/encryption"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
@@ -40,7 +40,7 @@ func TestMultipartUploadInvalidPart(t *testing.T) {
 	etag1, _ := uploadPart(hc, bktName, objName, multipartUpload.UploadID, 1, partSize)
 	etag2, _ := uploadPart(hc, bktName, objName, multipartUpload.UploadID, 2, partSize)
 	w := completeMultipartUploadBase(hc, bktName, objName, multipartUpload.UploadID, []string{etag1, etag2})
-	assertS3Error(hc.t, w, s3Errors.GetAPIError(s3Errors.ErrEntityTooSmall))
+	assertS3Error(hc.t, w, apierr.GetAPIError(apierr.ErrEntityTooSmall))
 }
 
 func TestDeleteMultipartAllParts(t *testing.T) {
@@ -104,7 +104,7 @@ func TestMultipartReUploadPart(t *testing.T) {
 	require.Equal(t, etag2, list.Parts[1].ETag)
 
 	w := completeMultipartUploadBase(hc, bktName, objName, uploadInfo.UploadID, []string{etag1, etag2})
-	assertS3Error(hc.t, w, s3Errors.GetAPIError(s3Errors.ErrEntityTooSmall))
+	assertS3Error(hc.t, w, apierr.GetAPIError(apierr.ErrEntityTooSmall))
 
 	etag1, data1 := uploadPart(hc, bktName, objName, uploadInfo.UploadID, 1, partSizeFirst)
 	etag2, data2 := uploadPart(hc, bktName, objName, uploadInfo.UploadID, 2, partSizeLast)
@@ -521,7 +521,7 @@ func TestUploadPartCheckContentSHA256(t *testing.T) {
 			r.Header.Set(api.AmzContentSha256, tc.hash)
 			hc.Handler().UploadPartHandler(w, r)
 			if tc.error {
-				assertS3Error(t, w, s3Errors.GetAPIError(s3Errors.ErrContentSHA256Mismatch))
+				assertS3Error(t, w, apierr.GetAPIError(apierr.ErrContentSHA256Mismatch))
 
 				list := listParts(hc, bktName, objName, multipartUpload.UploadID, "0", http.StatusOK)
 				require.Len(t, list.Parts, 1)
diff --git a/api/handler/patch_test.go b/api/handler/patch_test.go
index 32b0e13..e4c7e4a 100644
--- a/api/handler/patch_test.go
+++ b/api/handler/patch_test.go
@@ -18,7 +18,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
 	"github.com/stretchr/testify/require"
 )
@@ -50,7 +50,7 @@ func TestPatch(t *testing.T) {
 		name    string
 		rng     string
 		headers map[string]string
-		code    s3errors.ErrorCode
+		code    apierr.ErrorCode
 	}{
 		{
 			name: "success",
@@ -63,22 +63,22 @@ func TestPatch(t *testing.T) {
 		{
 			name: "invalid range syntax",
 			rng:  "bytes 0-2",
-			code: s3errors.ErrInvalidRange,
+			code: apierr.ErrInvalidRange,
 		},
 		{
 			name: "invalid range length",
 			rng:  "bytes 0-5/*",
-			code: s3errors.ErrInvalidRangeLength,
+			code: apierr.ErrInvalidRangeLength,
 		},
 		{
 			name: "invalid range start",
 			rng:  "bytes 20-22/*",
-			code: s3errors.ErrRangeOutOfBounds,
+			code: apierr.ErrRangeOutOfBounds,
 		},
 		{
 			name: "range is too long",
 			rng:  "bytes 0-5368709120/*",
-			code: s3errors.ErrInvalidRange,
+			code: apierr.ErrInvalidRange,
 		},
 		{
 			name: "If-Unmodified-Since precondition are not satisfied",
@@ -86,7 +86,7 @@ func TestPatch(t *testing.T) {
 			headers: map[string]string{
 				api.IfUnmodifiedSince: created.Add(-24 * time.Hour).Format(http.TimeFormat),
 			},
-			code: s3errors.ErrPreconditionFailed,
+			code: apierr.ErrPreconditionFailed,
 		},
 		{
 			name: "If-Match precondition are not satisfied",
@@ -94,7 +94,7 @@ func TestPatch(t *testing.T) {
 			headers: map[string]string{
 				api.IfMatch: "etag",
 			},
-			code: s3errors.ErrPreconditionFailed,
+			code: apierr.ErrPreconditionFailed,
 		},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
@@ -377,7 +377,7 @@ func TestPatchEncryptedObject(t *testing.T) {
 	tc.Handler().PutObjectHandler(w, r)
 	assertStatus(t, w, http.StatusOK)
 
-	patchObjectErr(t, tc, bktName, objName, "bytes 2-4/*", []byte("new"), nil, s3errors.ErrInternalError)
+	patchObjectErr(t, tc, bktName, objName, "bytes 2-4/*", []byte("new"), nil, apierr.ErrInternalError)
 }
 
 func TestPatchMissingHeaders(t *testing.T) {
@@ -393,13 +393,13 @@ func TestPatchMissingHeaders(t *testing.T) {
 	w = httptest.NewRecorder()
 	r = httptest.NewRequest(http.MethodPatch, defaultURL, strings.NewReader("new"))
 	tc.Handler().PatchObjectHandler(w, r)
-	assertS3Error(t, w, s3errors.GetAPIError(s3errors.ErrMissingContentRange))
+	assertS3Error(t, w, apierr.GetAPIError(apierr.ErrMissingContentRange))
 
 	w = httptest.NewRecorder()
 	r = httptest.NewRequest(http.MethodPatch, defaultURL, strings.NewReader("new"))
 	r.Header.Set(api.ContentRange, "bytes 0-2/*")
 	tc.Handler().PatchObjectHandler(w, r)
-	assertS3Error(t, w, s3errors.GetAPIError(s3errors.ErrMissingContentLength))
+	assertS3Error(t, w, apierr.GetAPIError(apierr.ErrMissingContentLength))
 }
 
 func TestParsePatchByteRange(t *testing.T) {
@@ -501,9 +501,9 @@ func patchObjectVersion(t *testing.T, tc *handlerContext, bktName, objName, vers
 	return result
 }
 
-func patchObjectErr(t *testing.T, tc *handlerContext, bktName, objName, rng string, payload []byte, headers map[string]string, code s3errors.ErrorCode) {
+func patchObjectErr(t *testing.T, tc *handlerContext, bktName, objName, rng string, payload []byte, headers map[string]string, code apierr.ErrorCode) {
 	w := patchObjectBase(tc, bktName, objName, "", rng, payload, headers)
-	assertS3Error(t, w, s3errors.GetAPIError(code))
+	assertS3Error(t, w, apierr.GetAPIError(code))
 }
 
 func patchObjectBase(tc *handlerContext, bktName, objName, version, rng string, payload []byte, headers map[string]string) *httptest.ResponseRecorder {
diff --git a/api/handler/put.go b/api/handler/put.go
index f9bff09..009dbb0 100644
--- a/api/handler/put.go
+++ b/api/handler/put.go
@@ -7,7 +7,7 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"encoding/xml"
-	stderrors "errors"
+	"errors"
 	"fmt"
 	"io"
 	"mime/multipart"
@@ -21,7 +21,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/auth"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/encryption"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
@@ -92,11 +92,11 @@ func (p *postPolicy) CheckField(key string, value string) error {
 	}
 	cond := p.condition(key)
 	if cond == nil {
-		return errors.GetAPIError(errors.ErrPostPolicyConditionInvalidFormat)
+		return apierr.GetAPIError(apierr.ErrPostPolicyConditionInvalidFormat)
 	}
 
 	if !cond.match(value) {
-		return errors.GetAPIError(errors.ErrPostPolicyConditionInvalidFormat)
+		return apierr.GetAPIError(apierr.ErrPostPolicyConditionInvalidFormat)
 	}
 
 	return nil
@@ -204,7 +204,7 @@ func (h *handler) PutObjectHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if cannedACLStatus == aclStatusYes {
-		h.logAndSendError(w, "acl not supported for this bucket", reqInfo, errors.GetAPIError(errors.ErrAccessControlListNotSupported))
+		h.logAndSendError(w, "acl not supported for this bucket", reqInfo, apierr.GetAPIError(apierr.ErrAccessControlListNotSupported))
 		return
 	}
 
@@ -333,16 +333,16 @@ func (h *handler) getBodyReader(r *http.Request) (io.ReadCloser, error) {
 
 	if !chunkedEncoding && !h.cfg.BypassContentEncodingInChunks() {
 		return nil, fmt.Errorf("%w: request is not chunk encoded, encodings '%s'",
-			errors.GetAPIError(errors.ErrInvalidEncodingMethod), strings.Join(encodings, ","))
+			apierr.GetAPIError(apierr.ErrInvalidEncodingMethod), strings.Join(encodings, ","))
 	}
 
 	decodeContentSize := r.Header.Get(api.AmzDecodedContentLength)
 	if len(decodeContentSize) == 0 {
-		return nil, errors.GetAPIError(errors.ErrMissingContentLength)
+		return nil, apierr.GetAPIError(apierr.ErrMissingContentLength)
 	}
 
 	if _, err := strconv.Atoi(decodeContentSize); err != nil {
-		return nil, fmt.Errorf("%w: parse decoded content length: %s", errors.GetAPIError(errors.ErrMissingContentLength), err.Error())
+		return nil, fmt.Errorf("%w: parse decoded content length: %s", apierr.GetAPIError(apierr.ErrMissingContentLength), err.Error())
 	}
 
 	chunkReader, err := newSignV4ChunkedReader(r)
@@ -378,43 +378,43 @@ func formEncryptionParamsBase(r *http.Request, isCopySource bool) (enc encryptio
 	}
 
 	if r.TLS == nil {
-		return enc, errors.GetAPIError(errors.ErrInsecureSSECustomerRequest)
+		return enc, apierr.GetAPIError(apierr.ErrInsecureSSECustomerRequest)
 	}
 
 	if len(sseCustomerKey) > 0 && len(sseCustomerAlgorithm) == 0 {
-		return enc, errors.GetAPIError(errors.ErrMissingSSECustomerAlgorithm)
+		return enc, apierr.GetAPIError(apierr.ErrMissingSSECustomerAlgorithm)
 	}
 	if len(sseCustomerAlgorithm) > 0 && len(sseCustomerKey) == 0 {
-		return enc, errors.GetAPIError(errors.ErrMissingSSECustomerKey)
+		return enc, apierr.GetAPIError(apierr.ErrMissingSSECustomerKey)
 	}
 
 	if sseCustomerAlgorithm != layer.AESEncryptionAlgorithm {
-		return enc, errors.GetAPIError(errors.ErrInvalidEncryptionAlgorithm)
+		return enc, apierr.GetAPIError(apierr.ErrInvalidEncryptionAlgorithm)
 	}
 
 	key, err := base64.StdEncoding.DecodeString(sseCustomerKey)
 	if err != nil {
 		if isCopySource {
-			return enc, errors.GetAPIError(errors.ErrInvalidSSECustomerParameters)
+			return enc, apierr.GetAPIError(apierr.ErrInvalidSSECustomerParameters)
 		}
-		return enc, errors.GetAPIError(errors.ErrInvalidSSECustomerKey)
+		return enc, apierr.GetAPIError(apierr.ErrInvalidSSECustomerKey)
 	}
 
 	if len(key) != layer.AESKeySize {
 		if isCopySource {
-			return enc, errors.GetAPIError(errors.ErrInvalidSSECustomerParameters)
+			return enc, apierr.GetAPIError(apierr.ErrInvalidSSECustomerParameters)
 		}
-		return enc, errors.GetAPIError(errors.ErrInvalidSSECustomerKey)
+		return enc, apierr.GetAPIError(apierr.ErrInvalidSSECustomerKey)
 	}
 
 	keyMD5, err := base64.StdEncoding.DecodeString(sseCustomerKeyMD5)
 	if err != nil {
-		return enc, errors.GetAPIError(errors.ErrSSECustomerKeyMD5Mismatch)
+		return enc, apierr.GetAPIError(apierr.ErrSSECustomerKeyMD5Mismatch)
 	}
 
 	md5Sum := md5.Sum(key)
 	if !bytes.Equal(md5Sum[:], keyMD5) {
-		return enc, errors.GetAPIError(errors.ErrSSECustomerKeyMD5Mismatch)
+		return enc, apierr.GetAPIError(apierr.ErrSSECustomerKeyMD5Mismatch)
 	}
 
 	params, err := encryption.NewParams(key)
@@ -444,7 +444,7 @@ func (h *handler) PostObject(w http.ResponseWriter, r *http.Request) {
 		tags := new(data.Tagging)
 		if err = h.cfg.NewXMLDecoder(buffer).Decode(tags); err != nil {
 			h.logAndSendError(w, "could not decode tag set", reqInfo,
-				fmt.Errorf("%w: %s", errors.GetAPIError(errors.ErrMalformedXML), err.Error()))
+				fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrMalformedXML), err.Error()))
 			return
 		}
 		tagSet, err = h.readTagSet(tags)
@@ -467,7 +467,7 @@ func (h *handler) PostObject(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if acl := auth.MultipartFormValue(r, "acl"); acl != "" && acl != basicACLPrivate {
-		h.logAndSendError(w, "acl not supported for this bucket", reqInfo, errors.GetAPIError(errors.ErrAccessControlListNotSupported))
+		h.logAndSendError(w, "acl not supported for this bucket", reqInfo, apierr.GetAPIError(apierr.ErrAccessControlListNotSupported))
 		return
 	}
 
@@ -508,12 +508,12 @@ func (h *handler) PostObject(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if reqInfo.ObjectName == "" {
-		h.logAndSendError(w, "missing object name", reqInfo, errors.GetAPIError(errors.ErrInvalidArgument))
+		h.logAndSendError(w, "missing object name", reqInfo, apierr.GetAPIError(apierr.ErrInvalidArgument))
 		return
 	}
 
 	if !policy.CheckContentLength(size) {
-		h.logAndSendError(w, "invalid content-length", reqInfo, errors.GetAPIError(errors.ErrInvalidArgument))
+		h.logAndSendError(w, "invalid content-length", reqInfo, apierr.GetAPIError(apierr.ErrInvalidArgument))
 		return
 	}
 
@@ -595,13 +595,13 @@ func checkPostPolicy(r *http.Request, reqInfo *middleware.ReqInfo, metadata map[
 			return nil, fmt.Errorf("could not unmarshal policy: %w", err)
 		}
 		if policy.Expiration.Before(time.Now()) {
-			return nil, fmt.Errorf("policy is expired: %w", errors.GetAPIError(errors.ErrInvalidArgument))
+			return nil, fmt.Errorf("policy is expired: %w", apierr.GetAPIError(apierr.ErrInvalidArgument))
 		}
 		policy.empty = false
 	}
 
 	if r.MultipartForm == nil {
-		return nil, stderrors.New("empty multipart form")
+		return nil, errors.New("empty multipart form")
 	}
 
 	for key, v := range r.MultipartForm.Value {
@@ -632,7 +632,7 @@ func checkPostPolicy(r *http.Request, reqInfo *middleware.ReqInfo, metadata map[
 	for _, cond := range policy.Conditions {
 		if cond.Key == "bucket" {
 			if !cond.match(reqInfo.BucketName) {
-				return nil, errors.GetAPIError(errors.ErrPostPolicyConditionInvalidFormat)
+				return nil, apierr.GetAPIError(apierr.ErrPostPolicyConditionInvalidFormat)
 			}
 		}
 	}
@@ -674,10 +674,10 @@ func parseTaggingHeader(header http.Header) (map[string]string, error) {
 	if tagging := header.Get(api.AmzTagging); len(tagging) > 0 {
 		queries, err := url.ParseQuery(tagging)
 		if err != nil {
-			return nil, errors.GetAPIError(errors.ErrInvalidArgument)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidArgument)
 		}
 		if len(queries) > maxTags {
-			return nil, errors.GetAPIError(errors.ErrInvalidTagsSizeExceed)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidTagsSizeExceed)
 		}
 		tagSet = make(map[string]string, len(queries))
 		for k, v := range queries {
@@ -727,7 +727,7 @@ func (h *handler) parseCommonCreateBucketParams(reqInfo *middleware.ReqInfo, box
 	}
 
 	if p.SessionContainerCreation == nil {
-		return nil, nil, fmt.Errorf("%w: couldn't find session token for put", errors.GetAPIError(errors.ErrAccessDenied))
+		return nil, nil, fmt.Errorf("%w: couldn't find session token for put", apierr.GetAPIError(apierr.ErrAccessDenied))
 	}
 
 	if err := checkBucketName(reqInfo.BucketName); err != nil {
@@ -853,7 +853,7 @@ func (h *handler) putBucketSettingsRetryer() aws.RetryerV2 {
 		}
 
 		options.Retryables = []retry.IsErrorRetryable{retry.IsErrorRetryableFunc(func(err error) aws.Ternary {
-			if stderrors.Is(err, tree.ErrNodeAccessDenied) {
+			if errors.Is(err, tree.ErrNodeAccessDenied) {
 				return aws.TrueTernary
 			}
 			return aws.FalseTernary
@@ -982,7 +982,7 @@ func (h handler) setPlacementPolicy(prm *layer.CreateBucketParams, namespace, lo
 		return nil
 	}
 
-	return errors.GetAPIError(errors.ErrInvalidLocationConstraint)
+	return apierr.GetAPIError(apierr.ErrInvalidLocationConstraint)
 }
 
 func isLockEnabled(log *zap.Logger, header http.Header) bool {
@@ -1001,27 +1001,27 @@ func isLockEnabled(log *zap.Logger, header http.Header) bool {
 
 func checkBucketName(bucketName string) error {
 	if len(bucketName) < 3 || len(bucketName) > 63 {
-		return errors.GetAPIError(errors.ErrInvalidBucketName)
+		return apierr.GetAPIError(apierr.ErrInvalidBucketName)
 	}
 
 	if strings.HasPrefix(bucketName, "xn--") || strings.HasSuffix(bucketName, "-s3alias") {
-		return errors.GetAPIError(errors.ErrInvalidBucketName)
+		return apierr.GetAPIError(apierr.ErrInvalidBucketName)
 	}
 	if net.ParseIP(bucketName) != nil {
-		return errors.GetAPIError(errors.ErrInvalidBucketName)
+		return apierr.GetAPIError(apierr.ErrInvalidBucketName)
 	}
 
 	labels := strings.Split(bucketName, ".")
 	for _, label := range labels {
 		if len(label) == 0 {
-			return errors.GetAPIError(errors.ErrInvalidBucketName)
+			return apierr.GetAPIError(apierr.ErrInvalidBucketName)
 		}
 		for i, r := range label {
 			if !isAlphaNum(r) && r != '-' {
-				return errors.GetAPIError(errors.ErrInvalidBucketName)
+				return apierr.GetAPIError(apierr.ErrInvalidBucketName)
 			}
 			if (i == 0 || i == len(label)-1) && r == '-' {
-				return errors.GetAPIError(errors.ErrInvalidBucketName)
+				return apierr.GetAPIError(apierr.ErrInvalidBucketName)
 			}
 		}
 	}
@@ -1040,7 +1040,7 @@ func (h *handler) parseLocationConstraint(r *http.Request) (*createBucketParams,
 
 	params := new(createBucketParams)
 	if err := h.cfg.NewXMLDecoder(r.Body).Decode(params); err != nil {
-		return nil, fmt.Errorf("%w: %s", errors.GetAPIError(errors.ErrMalformedXML), err.Error())
+		return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrMalformedXML), err.Error())
 	}
 	return params, nil
 }
diff --git a/api/handler/put_test.go b/api/handler/put_test.go
index f11f9ea..66dca11 100644
--- a/api/handler/put_test.go
+++ b/api/handler/put_test.go
@@ -21,7 +21,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/auth"
 	v4 "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/auth/signer/v4"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
@@ -205,7 +205,7 @@ func TestPostObject(t *testing.T) {
 		t.Run(tc.key+";"+tc.filename, func(t *testing.T) {
 			w := postObjectBase(hc, ns, bktName, tc.key, tc.filename, tc.content)
 			if tc.err {
-				assertS3Error(hc.t, w, s3errors.GetAPIError(s3errors.ErrInternalError))
+				assertS3Error(hc.t, w, apierr.GetAPIError(apierr.ErrInternalError))
 				return
 			}
 			assertStatus(hc.t, w, http.StatusNoContent)
@@ -268,7 +268,7 @@ func TestPutObjectWithStreamBodyError(t *testing.T) {
 	r.Header.Set(api.AmzContentSha256, api.StreamingContentSHA256)
 	r.Header.Set(api.ContentEncoding, api.AwsChunked)
 	tc.Handler().PutObjectHandler(w, r)
-	assertS3Error(t, w, s3errors.GetAPIError(s3errors.ErrMissingContentLength))
+	assertS3Error(t, w, apierr.GetAPIError(apierr.ErrMissingContentLength))
 
 	checkNotFound(t, tc, bktName, objName, emptyVersion)
 }
@@ -284,7 +284,7 @@ func TestPutObjectWithInvalidContentMD5(t *testing.T) {
 	w, r := prepareTestPayloadRequest(tc, bktName, objName, bytes.NewReader(content))
 	r.Header.Set(api.ContentMD5, base64.StdEncoding.EncodeToString([]byte("invalid")))
 	tc.Handler().PutObjectHandler(w, r)
-	assertS3Error(t, w, s3errors.GetAPIError(s3errors.ErrInvalidDigest))
+	assertS3Error(t, w, apierr.GetAPIError(apierr.ErrInvalidDigest))
 
 	checkNotFound(t, tc, bktName, objName, emptyVersion)
 }
@@ -347,7 +347,7 @@ func TestPutObjectCheckContentSHA256(t *testing.T) {
 			hc.Handler().PutObjectHandler(w, r)
 
 			if tc.error {
-				assertS3Error(t, w, s3errors.GetAPIError(s3errors.ErrContentSHA256Mismatch))
+				assertS3Error(t, w, apierr.GetAPIError(apierr.ErrContentSHA256Mismatch))
 
 				w, r := prepareTestRequest(hc, bktName, objName, nil)
 				hc.Handler().GetObjectHandler(w, r)
@@ -400,7 +400,7 @@ func TestPutChunkedTestContentEncoding(t *testing.T) {
 	w, req, _ = getChunkedRequest(hc.context, t, bktName, objName)
 	req.Header.Set(api.ContentEncoding, "gzip")
 	hc.Handler().PutObjectHandler(w, req)
-	assertS3Error(t, w, s3errors.GetAPIError(s3errors.ErrInvalidEncodingMethod))
+	assertS3Error(t, w, apierr.GetAPIError(apierr.ErrInvalidEncodingMethod))
 
 	hc.config.bypassContentEncodingInChunks = true
 	w, req, _ = getChunkedRequest(hc.context, t, bktName, objName)
@@ -479,10 +479,10 @@ func TestCreateBucket(t *testing.T) {
 	bktName := "bkt-name"
 
 	info := createBucket(hc, bktName)
-	createBucketAssertS3Error(hc, bktName, info.Box, s3errors.ErrBucketAlreadyOwnedByYou)
+	createBucketAssertS3Error(hc, bktName, info.Box, apierr.ErrBucketAlreadyOwnedByYou)
 
 	box2, _ := createAccessBox(t)
-	createBucketAssertS3Error(hc, bktName, box2, s3errors.ErrBucketAlreadyExists)
+	createBucketAssertS3Error(hc, bktName, box2, apierr.ErrBucketAlreadyExists)
 }
 
 func TestCreateBucketWithoutPermissions(t *testing.T) {
diff --git a/api/handler/tagging_test.go b/api/handler/tagging_test.go
index 5537aa6..ddfa45f 100644
--- a/api/handler/tagging_test.go
+++ b/api/handler/tagging_test.go
@@ -6,7 +6,7 @@ import (
 	"testing"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"github.com/stretchr/testify/require"
 )
@@ -98,7 +98,7 @@ func TestPutObjectTaggingCheckUniqueness(t *testing.T) {
 			middleware.GetReqInfo(r.Context()).Tagging = tc.body
 			hc.Handler().PutObjectTaggingHandler(w, r)
 			if tc.error {
-				assertS3Error(t, w, apiErrors.GetAPIError(apiErrors.ErrInvalidTagKeyUniqueness))
+				assertS3Error(t, w, apierr.GetAPIError(apierr.ErrInvalidTagKeyUniqueness))
 				return
 			}
 			assertStatus(t, w, http.StatusOK)
diff --git a/api/handler/util.go b/api/handler/util.go
index 23a087a..7b675c8 100644
--- a/api/handler/util.go
+++ b/api/handler/util.go
@@ -10,7 +10,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
@@ -59,25 +59,25 @@ func handleDeleteMarker(w http.ResponseWriter, err error) error {
 	}
 
 	w.Header().Set(api.AmzDeleteMarker, "true")
-	return fmt.Errorf("%w: %s", s3errors.GetAPIError(target.ErrorCode), err)
+	return fmt.Errorf("%w: %s", apierr.GetAPIError(target.ErrorCode), err)
 }
 
 func transformToS3Error(err error) error {
 	err = frosterrors.UnwrapErr(err) // this wouldn't work with errors.Join
-	if _, ok := err.(s3errors.Error); ok {
+	if _, ok := err.(apierr.Error); ok {
 		return err
 	}
 
 	if errors.Is(err, frostfs.ErrAccessDenied) ||
 		errors.Is(err, tree.ErrNodeAccessDenied) {
-		return s3errors.GetAPIError(s3errors.ErrAccessDenied)
+		return apierr.GetAPIError(apierr.ErrAccessDenied)
 	}
 
 	if errors.Is(err, frostfs.ErrGatewayTimeout) {
-		return s3errors.GetAPIError(s3errors.ErrGatewayTimeout)
+		return apierr.GetAPIError(apierr.ErrGatewayTimeout)
 	}
 
-	return s3errors.GetAPIError(s3errors.ErrInternalError)
+	return apierr.GetAPIError(apierr.ErrInternalError)
 }
 
 func (h *handler) ResolveBucket(ctx context.Context, bucket string) (*data.BucketInfo, error) {
@@ -133,26 +133,26 @@ func parseRange(s string) (*layer.RangeParams, error) {
 	prefix := "bytes="
 
 	if !strings.HasPrefix(s, prefix) {
-		return nil, s3errors.GetAPIError(s3errors.ErrInvalidRange)
+		return nil, apierr.GetAPIError(apierr.ErrInvalidRange)
 	}
 
 	s = strings.TrimPrefix(s, prefix)
 
 	valuesStr := strings.Split(s, "-")
 	if len(valuesStr) != 2 {
-		return nil, s3errors.GetAPIError(s3errors.ErrInvalidRange)
+		return nil, apierr.GetAPIError(apierr.ErrInvalidRange)
 	}
 
 	values := make([]uint64, 0, len(valuesStr))
 	for _, v := range valuesStr {
 		num, err := strconv.ParseUint(v, 10, 64)
 		if err != nil {
-			return nil, s3errors.GetAPIError(s3errors.ErrInvalidRange)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidRange)
 		}
 		values = append(values, num)
 	}
 	if values[0] > values[1] {
-		return nil, s3errors.GetAPIError(s3errors.ErrInvalidRange)
+		return nil, apierr.GetAPIError(apierr.ErrInvalidRange)
 	}
 
 	return &layer.RangeParams{
diff --git a/api/layer/compound.go b/api/layer/compound.go
index 28fc61e..83f3805 100644
--- a/api/layer/compound.go
+++ b/api/layer/compound.go
@@ -6,7 +6,7 @@ import (
 	"fmt"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
 )
 
@@ -31,7 +31,7 @@ func (n *Layer) GetObjectTaggingAndLock(ctx context.Context, objVersion *data.Ob
 	tags, lockInfo, err = n.treeService.GetObjectTaggingAndLock(ctx, objVersion.BktInfo, nodeVersion)
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeNotFound) {
-			return nil, data.LockInfo{}, fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchKey), err.Error())
+			return nil, data.LockInfo{}, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error())
 		}
 		return nil, data.LockInfo{}, err
 	}
diff --git a/api/layer/container.go b/api/layer/container.go
index 622dc4f..4956cf3 100644
--- a/api/layer/container.go
+++ b/api/layer/container.go
@@ -7,7 +7,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
@@ -38,7 +38,7 @@ func (n *Layer) containerInfo(ctx context.Context, prm frostfs.PrmContainer) (*d
 	res, err = n.frostFS.Container(ctx, prm)
 	if err != nil {
 		if client.IsErrContainerNotFound(err) {
-			return nil, fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchBucket), err.Error())
+			return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchBucket), err.Error())
 		}
 		return nil, fmt.Errorf("get frostfs container: %w", err)
 	}
diff --git a/api/layer/cors.go b/api/layer/cors.go
index dfefd09..49b6cc4 100644
--- a/api/layer/cors.go
+++ b/api/layer/cors.go
@@ -3,12 +3,12 @@ package layer
 import (
 	"bytes"
 	"context"
-	errorsStd "errors"
+	"errors"
 	"fmt"
 	"io"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
@@ -33,7 +33,7 @@ func (n *Layer) PutBucketCORS(ctx context.Context, p *PutCORSParams) error {
 	}
 
 	if cors.CORSRules == nil {
-		return errors.GetAPIError(errors.ErrMalformedXML)
+		return apierr.GetAPIError(apierr.ErrMalformedXML)
 	}
 
 	if err := checkCORS(cors); err != nil {
@@ -63,7 +63,7 @@ func (n *Layer) PutBucketCORS(ctx context.Context, p *PutCORSParams) error {
 	}
 
 	objsToDelete, err := n.treeService.PutBucketCORS(ctx, p.BktInfo, newAddress(corsBkt.CID, createdObj.ID))
-	objToDeleteNotFound := errorsStd.Is(err, tree.ErrNoNodeToRemove)
+	objToDeleteNotFound := errors.Is(err, tree.ErrNoNodeToRemove)
 	if err != nil && !objToDeleteNotFound {
 		return err
 	}
@@ -106,7 +106,7 @@ func (n *Layer) GetBucketCORS(ctx context.Context, bktInfo *data.BucketInfo) (*d
 
 func (n *Layer) DeleteBucketCORS(ctx context.Context, bktInfo *data.BucketInfo) error {
 	objs, err := n.treeService.DeleteBucketCORS(ctx, bktInfo)
-	objNotFound := errorsStd.Is(err, tree.ErrNoNodeToRemove)
+	objNotFound := errors.Is(err, tree.ErrNoNodeToRemove)
 	if err != nil && !objNotFound {
 		return err
 	}
@@ -126,12 +126,12 @@ func checkCORS(cors *data.CORSConfiguration) error {
 	for _, r := range cors.CORSRules {
 		for _, m := range r.AllowedMethods {
 			if _, ok := supportedMethods[m]; !ok {
-				return errors.GetAPIErrorWithError(errors.ErrCORSUnsupportedMethod, fmt.Errorf("unsupported method is %s", m))
+				return apierr.GetAPIErrorWithError(apierr.ErrCORSUnsupportedMethod, fmt.Errorf("unsupported method is %s", m))
 			}
 		}
 		for _, h := range r.ExposeHeaders {
 			if h == wildcard {
-				return errors.GetAPIError(errors.ErrCORSWildcardExposeHeaders)
+				return apierr.GetAPIError(apierr.ErrCORSWildcardExposeHeaders)
 			}
 		}
 	}
diff --git a/api/layer/layer.go b/api/layer/layer.go
index 172b5d2..17646c9 100644
--- a/api/layer/layer.go
+++ b/api/layer/layer.go
@@ -6,7 +6,7 @@ import (
 	"crypto/rand"
 	"encoding/json"
 	"encoding/xml"
-	stderrors "errors"
+	"errors"
 	"fmt"
 	"io"
 	"net/url"
@@ -17,8 +17,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/encryption"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
@@ -333,7 +332,7 @@ func (n *Layer) GetBucketInfo(ctx context.Context, name string) (*data.BucketInf
 	containerID, err := n.ResolveBucket(ctx, zone, name)
 	if err != nil {
 		if strings.Contains(err.Error(), "not found") {
-			return nil, fmt.Errorf("%w: %s", errors.GetAPIError(errors.ErrNoSuchBucket), err.Error())
+			return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchBucket), err.Error())
 		}
 		return nil, err
 	}
@@ -399,9 +398,9 @@ func (n *Layer) GetObject(ctx context.Context, p *GetObjectParams) (*ObjectPaylo
 	if err != nil {
 		if client.IsErrObjectNotFound(err) {
 			if p.Versioned {
-				err = fmt.Errorf("%w: %s", errors.GetAPIError(errors.ErrNoSuchVersion), err.Error())
+				err = fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchVersion), err.Error())
 			} else {
-				err = fmt.Errorf("%w: %s", errors.GetAPIError(errors.ErrNoSuchKey), err.Error())
+				err = fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error())
 			}
 		}
 
@@ -657,22 +656,22 @@ func (n *Layer) handleNotFoundError(bkt *data.BucketInfo, obj *VersionedObject)
 }
 
 func isNotFoundError(err error) bool {
-	return errors.IsS3Error(err, errors.ErrNoSuchKey) ||
-		errors.IsS3Error(err, errors.ErrNoSuchVersion)
+	return apierr.IsS3Error(err, apierr.ErrNoSuchKey) ||
+		apierr.IsS3Error(err, apierr.ErrNoSuchVersion)
 }
 
 func (n *Layer) getNodeVersionsToDelete(ctx context.Context, bkt *data.BucketInfo, obj *VersionedObject) ([]*data.NodeVersion, error) {
 	var versionsToDelete []*data.NodeVersion
 	versions, err := n.treeService.GetVersions(ctx, bkt, obj.Name)
 	if err != nil {
-		if stderrors.Is(err, tree.ErrNodeNotFound) {
-			return nil, fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchKey), err.Error())
+		if errors.Is(err, tree.ErrNodeNotFound) {
+			return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error())
 		}
 		return nil, err
 	}
 
 	if len(versions) == 0 {
-		return nil, fmt.Errorf("%w: there isn't tree node with requested version id", s3errors.GetAPIError(s3errors.ErrNoSuchVersion))
+		return nil, fmt.Errorf("%w: there isn't tree node with requested version id", apierr.GetAPIError(apierr.ErrNoSuchVersion))
 	}
 
 	sort.Slice(versions, func(i, j int) bool {
@@ -714,7 +713,7 @@ func (n *Layer) getNodeVersionsToDelete(ctx context.Context, bkt *data.BucketInf
 	}
 
 	if len(versionsToDelete) == 0 {
-		return nil, fmt.Errorf("%w: there isn't tree node with requested version id", s3errors.GetAPIError(s3errors.ErrNoSuchVersion))
+		return nil, fmt.Errorf("%w: there isn't tree node with requested version id", apierr.GetAPIError(apierr.ErrNoSuchVersion))
 	}
 
 	n.reqLogger(ctx).Debug(logs.GetTreeNodeToDelete, zap.Stringer("cid", bkt.CID), zap.Strings("oids", oids))
@@ -787,17 +786,17 @@ func (n *Layer) DeleteObjects(ctx context.Context, p *DeleteObjectParams) []*Ver
 func (n *Layer) CreateBucket(ctx context.Context, p *CreateBucketParams) (*data.BucketInfo, error) {
 	bktInfo, err := n.GetBucketInfo(ctx, p.Name)
 	if err != nil {
-		if errors.IsS3Error(err, errors.ErrNoSuchBucket) {
+		if apierr.IsS3Error(err, apierr.ErrNoSuchBucket) {
 			return n.createContainer(ctx, p)
 		}
 		return nil, err
 	}
 
 	if p.SessionContainerCreation != nil && session.IssuedBy(*p.SessionContainerCreation, bktInfo.Owner) {
-		return nil, errors.GetAPIError(errors.ErrBucketAlreadyOwnedByYou)
+		return nil, apierr.GetAPIError(apierr.ErrBucketAlreadyOwnedByYou)
 	}
 
-	return nil, errors.GetAPIError(errors.ErrBucketAlreadyExists)
+	return nil, apierr.GetAPIError(apierr.ErrBucketAlreadyExists)
 }
 
 func (n *Layer) ResolveBucket(ctx context.Context, zone, name string) (cid.ID, error) {
@@ -824,7 +823,7 @@ func (n *Layer) DeleteBucket(ctx context.Context, p *DeleteBucketParams) error {
 			return err
 		}
 		if len(res) != 0 {
-			return errors.GetAPIError(errors.ErrBucketNotEmpty)
+			return apierr.GetAPIError(apierr.ErrBucketNotEmpty)
 		}
 	}
 
diff --git a/api/layer/lifecycle.go b/api/layer/lifecycle.go
index dd84dee..8901cc6 100644
--- a/api/layer/lifecycle.go
+++ b/api/layer/lifecycle.go
@@ -10,7 +10,7 @@ import (
 	"io"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
@@ -51,13 +51,13 @@ func (n *Layer) PutBucketLifecycleConfiguration(ctx context.Context, p *PutBucke
 
 	hashBytes, err := base64.StdEncoding.DecodeString(p.MD5Hash)
 	if err != nil {
-		return apiErr.GetAPIError(apiErr.ErrInvalidDigest)
+		return apierr.GetAPIError(apierr.ErrInvalidDigest)
 	}
 
 	if !bytes.Equal(hashBytes, createdObj.MD5Sum) {
 		n.deleteLifecycleObject(ctx, p.BktInfo, newAddress(lifecycleBkt.CID, createdObj.ID))
 
-		return apiErr.GetAPIError(apiErr.ErrInvalidDigest)
+		return apierr.GetAPIError(apierr.ErrInvalidDigest)
 	}
 
 	objsToDelete, err := n.treeService.PutBucketLifecycleConfiguration(ctx, p.BktInfo, newAddress(lifecycleBkt.CID, createdObj.ID))
@@ -106,7 +106,7 @@ func (n *Layer) GetBucketLifecycleConfiguration(ctx context.Context, bktInfo *da
 	}
 
 	if objNotFound {
-		return nil, fmt.Errorf("%w: %s", apiErr.GetAPIError(apiErr.ErrNoSuchLifecycleConfiguration), err.Error())
+		return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchLifecycleConfiguration), err.Error())
 	}
 
 	var prmAuth frostfs.PrmAuth
diff --git a/api/layer/lifecycle_test.go b/api/layer/lifecycle_test.go
index ec89897..0e9be8f 100644
--- a/api/layer/lifecycle_test.go
+++ b/api/layer/lifecycle_test.go
@@ -8,8 +8,8 @@ import (
 	"testing"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
-	frostfsErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	frosterr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
 	"github.com/stretchr/testify/require"
 )
 
@@ -36,7 +36,7 @@ func TestBucketLifecycle(t *testing.T) {
 	hash.Write(lifecycleBytes)
 
 	_, err = tc.layer.GetBucketLifecycleConfiguration(tc.ctx, tc.bktInfo)
-	require.Equal(t, apiErr.GetAPIError(apiErr.ErrNoSuchLifecycleConfiguration), frostfsErrors.UnwrapErr(err))
+	require.Equal(t, apierr.GetAPIError(apierr.ErrNoSuchLifecycleConfiguration), frosterr.UnwrapErr(err))
 
 	err = tc.layer.DeleteBucketLifecycleConfiguration(tc.ctx, tc.bktInfo)
 	require.NoError(t, err)
@@ -57,7 +57,7 @@ func TestBucketLifecycle(t *testing.T) {
 	require.NoError(t, err)
 
 	_, err = tc.layer.GetBucketLifecycleConfiguration(tc.ctx, tc.bktInfo)
-	require.Equal(t, apiErr.GetAPIError(apiErr.ErrNoSuchLifecycleConfiguration), frostfsErrors.UnwrapErr(err))
+	require.Equal(t, apierr.GetAPIError(apierr.ErrNoSuchLifecycleConfiguration), frosterr.UnwrapErr(err))
 }
 
 func ptr[T any](t T) *T {
diff --git a/api/layer/listing.go b/api/layer/listing.go
index c72177f..abc8b7e 100644
--- a/api/layer/listing.go
+++ b/api/layer/listing.go
@@ -11,7 +11,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/cache"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
 	"github.com/panjf2000/ants/v2"
@@ -691,10 +691,10 @@ func filterVersionsByMarker(objects []*data.ExtendedNodeVersion, p *ListObjectVe
 					return objects[j+1:], nil
 				}
 			}
-			return nil, s3errors.GetAPIError(s3errors.ErrInvalidVersion)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidVersion)
 		} else if obj.NodeVersion.FilePath > p.KeyMarker {
 			if p.VersionIDMarker != "" {
-				return nil, s3errors.GetAPIError(s3errors.ErrInvalidVersion)
+				return nil, apierr.GetAPIError(apierr.ErrInvalidVersion)
 			}
 			return objects[i:], nil
 		}
diff --git a/api/layer/multipart_upload.go b/api/layer/multipart_upload.go
index c73b47f..ed7612c 100644
--- a/api/layer/multipart_upload.go
+++ b/api/layer/multipart_upload.go
@@ -17,7 +17,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/auth"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/encryption"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
@@ -190,13 +190,13 @@ func (n *Layer) UploadPart(ctx context.Context, p *UploadPartParams) (string, er
 	multipartInfo, err := n.treeService.GetMultipartUpload(ctx, p.Info.Bkt, p.Info.Key, p.Info.UploadID)
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeNotFound) {
-			return "", fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchUpload), err.Error())
+			return "", fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchUpload), err.Error())
 		}
 		return "", err
 	}
 
 	if p.Size > UploadMaxSize {
-		return "", fmt.Errorf("%w: %d/%d", s3errors.GetAPIError(s3errors.ErrEntityTooLarge), p.Size, UploadMaxSize)
+		return "", fmt.Errorf("%w: %d/%d", apierr.GetAPIError(apierr.ErrEntityTooLarge), p.Size, UploadMaxSize)
 	}
 
 	objInfo, err := n.uploadPart(ctx, multipartInfo, p)
@@ -211,7 +211,7 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 	encInfo := FormEncryptionInfo(multipartInfo.Meta)
 	if err := p.Info.Encryption.MatchObjectEncryption(encInfo); err != nil {
 		n.reqLogger(ctx).Warn(logs.MismatchedObjEncryptionInfo, zap.Error(err))
-		return nil, s3errors.GetAPIError(s3errors.ErrInvalidEncryptionParameters)
+		return nil, apierr.GetAPIError(apierr.ErrInvalidEncryptionParameters)
 	}
 
 	bktInfo := p.Info.Bkt
@@ -244,7 +244,7 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 	if len(p.ContentMD5) > 0 {
 		hashBytes, err := base64.StdEncoding.DecodeString(p.ContentMD5)
 		if err != nil {
-			return nil, s3errors.GetAPIError(s3errors.ErrInvalidDigest)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidDigest)
 		}
 		if hex.EncodeToString(hashBytes) != hex.EncodeToString(createdObj.MD5Sum) {
 			prm := frostfs.PrmObjectDelete{
@@ -256,7 +256,7 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 			if err != nil {
 				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", createdObj.ID))
 			}
-			return nil, s3errors.GetAPIError(s3errors.ErrInvalidDigest)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidDigest)
 		}
 	}
 	if p.Info.Encryption.Enabled() {
@@ -266,14 +266,14 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 	if !p.Info.Encryption.Enabled() && len(p.ContentSHA256Hash) > 0 && !auth.IsStandardContentSHA256(p.ContentSHA256Hash) {
 		contentHashBytes, err := hex.DecodeString(p.ContentSHA256Hash)
 		if err != nil {
-			return nil, s3errors.GetAPIError(s3errors.ErrContentSHA256Mismatch)
+			return nil, apierr.GetAPIError(apierr.ErrContentSHA256Mismatch)
 		}
 		if !bytes.Equal(contentHashBytes, createdObj.HashSum) {
 			err = n.objectDelete(ctx, bktInfo, createdObj.ID)
 			if err != nil {
 				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", createdObj.ID))
 			}
-			return nil, s3errors.GetAPIError(s3errors.ErrContentSHA256Mismatch)
+			return nil, apierr.GetAPIError(apierr.ErrContentSHA256Mismatch)
 		}
 	}
 
@@ -326,7 +326,7 @@ func (n *Layer) UploadPartCopy(ctx context.Context, p *UploadCopyParams) (*data.
 	multipartInfo, err := n.treeService.GetMultipartUpload(ctx, p.Info.Bkt, p.Info.Key, p.Info.UploadID)
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeNotFound) {
-			return nil, fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchUpload), err.Error())
+			return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchUpload), err.Error())
 		}
 		return nil, err
 	}
@@ -342,11 +342,11 @@ func (n *Layer) UploadPartCopy(ctx context.Context, p *UploadCopyParams) (*data.
 	if p.Range != nil {
 		size = p.Range.End - p.Range.Start + 1
 		if p.Range.End > srcObjectSize {
-			return nil, fmt.Errorf("%w: %d-%d/%d", s3errors.GetAPIError(s3errors.ErrInvalidCopyPartRangeSource), p.Range.Start, p.Range.End, srcObjectSize)
+			return nil, fmt.Errorf("%w: %d-%d/%d", apierr.GetAPIError(apierr.ErrInvalidCopyPartRangeSource), p.Range.Start, p.Range.End, srcObjectSize)
 		}
 	}
 	if size > UploadMaxSize {
-		return nil, fmt.Errorf("%w: %d/%d", s3errors.GetAPIError(s3errors.ErrEntityTooLarge), size, UploadMaxSize)
+		return nil, fmt.Errorf("%w: %d/%d", apierr.GetAPIError(apierr.ErrEntityTooLarge), size, UploadMaxSize)
 	}
 
 	objPayload, err := n.GetObject(ctx, &GetObjectParams{
@@ -373,7 +373,7 @@ func (n *Layer) UploadPartCopy(ctx context.Context, p *UploadCopyParams) (*data.
 func (n *Layer) CompleteMultipartUpload(ctx context.Context, p *CompleteMultipartParams) (*UploadData, *data.ExtendedObjectInfo, error) {
 	for i := 1; i < len(p.Parts); i++ {
 		if p.Parts[i].PartNumber <= p.Parts[i-1].PartNumber {
-			return nil, nil, s3errors.GetAPIError(s3errors.ErrInvalidPartOrder)
+			return nil, nil, apierr.GetAPIError(apierr.ErrInvalidPartOrder)
 		}
 	}
 
@@ -384,7 +384,7 @@ func (n *Layer) CompleteMultipartUpload(ctx context.Context, p *CompleteMultipar
 	encInfo := FormEncryptionInfo(multipartInfo.Meta)
 
 	if len(partsInfo) < len(p.Parts) {
-		return nil, nil, fmt.Errorf("%w: found %d parts, need %d", s3errors.GetAPIError(s3errors.ErrInvalidPart), len(partsInfo), len(p.Parts))
+		return nil, nil, fmt.Errorf("%w: found %d parts, need %d", apierr.GetAPIError(apierr.ErrInvalidPart), len(partsInfo), len(p.Parts))
 	}
 
 	var multipartObjetSize uint64
@@ -396,12 +396,12 @@ func (n *Layer) CompleteMultipartUpload(ctx context.Context, p *CompleteMultipar
 	for i, part := range p.Parts {
 		partInfo := partsInfo.Extract(part.PartNumber, data.UnQuote(part.ETag), n.features.MD5Enabled())
 		if partInfo == nil {
-			return nil, nil, fmt.Errorf("%w: unknown part %d or etag mismatched", s3errors.GetAPIError(s3errors.ErrInvalidPart), part.PartNumber)
+			return nil, nil, fmt.Errorf("%w: unknown part %d or etag mismatched", apierr.GetAPIError(apierr.ErrInvalidPart), part.PartNumber)
 		}
 
 		// for the last part we have no minimum size limit
 		if i != len(p.Parts)-1 && partInfo.Size < UploadMinSize {
-			return nil, nil, fmt.Errorf("%w: %d/%d", s3errors.GetAPIError(s3errors.ErrEntityTooSmall), partInfo.Size, UploadMinSize)
+			return nil, nil, fmt.Errorf("%w: %d/%d", apierr.GetAPIError(apierr.ErrEntityTooSmall), partInfo.Size, UploadMinSize)
 		}
 		parts = append(parts, partInfo)
 		multipartObjetSize += partInfo.Size // even if encryption is enabled size is actual (decrypted)
@@ -473,7 +473,7 @@ func (n *Layer) CompleteMultipartUpload(ctx context.Context, p *CompleteMultipar
 			zap.String("uploadKey", p.Info.Key),
 			zap.Error(err))
 
-		return nil, nil, s3errors.GetAPIError(s3errors.ErrInternalError)
+		return nil, nil, apierr.GetAPIError(apierr.ErrInternalError)
 	}
 
 	var addr oid.Address
@@ -581,7 +581,7 @@ func (n *Layer) ListParts(ctx context.Context, p *ListPartsParams) (*ListPartsIn
 	encInfo := FormEncryptionInfo(multipartInfo.Meta)
 	if err = p.Info.Encryption.MatchObjectEncryption(encInfo); err != nil {
 		n.reqLogger(ctx).Warn(logs.MismatchedObjEncryptionInfo, zap.Error(err))
-		return nil, s3errors.GetAPIError(s3errors.ErrInvalidEncryptionParameters)
+		return nil, apierr.GetAPIError(apierr.ErrInvalidEncryptionParameters)
 	}
 
 	res.Owner = multipartInfo.Owner
@@ -649,7 +649,7 @@ func (n *Layer) getUploadParts(ctx context.Context, p *UploadInfoParams) (*data.
 	multipartInfo, err := n.treeService.GetMultipartUpload(ctx, p.Bkt, p.Key, p.UploadID)
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeNotFound) {
-			return nil, nil, fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchUpload), err.Error())
+			return nil, nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchUpload), err.Error())
 		}
 		return nil, nil, err
 	}
diff --git a/api/layer/object.go b/api/layer/object.go
index a5cfcf9..8260740 100644
--- a/api/layer/object.go
+++ b/api/layer/object.go
@@ -20,7 +20,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/auth"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
@@ -51,7 +51,7 @@ type (
 	}
 
 	DeleteMarkerError struct {
-		ErrorCode apiErrors.ErrorCode
+		ErrorCode apierr.ErrorCode
 	}
 )
 
@@ -289,28 +289,28 @@ func (n *Layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 	if !p.Encryption.Enabled() && len(p.ContentMD5) > 0 {
 		headerMd5Hash, err := base64.StdEncoding.DecodeString(p.ContentMD5)
 		if err != nil {
-			return nil, apiErrors.GetAPIError(apiErrors.ErrInvalidDigest)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidDigest)
 		}
 		if !bytes.Equal(headerMd5Hash, createdObj.MD5Sum) {
 			err = n.objectDelete(ctx, p.BktInfo, createdObj.ID)
 			if err != nil {
 				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", createdObj.ID))
 			}
-			return nil, apiErrors.GetAPIError(apiErrors.ErrInvalidDigest)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidDigest)
 		}
 	}
 
 	if !p.Encryption.Enabled() && len(p.ContentSHA256Hash) > 0 && !auth.IsStandardContentSHA256(p.ContentSHA256Hash) {
 		contentHashBytes, err := hex.DecodeString(p.ContentSHA256Hash)
 		if err != nil {
-			return nil, apiErrors.GetAPIError(apiErrors.ErrContentSHA256Mismatch)
+			return nil, apierr.GetAPIError(apierr.ErrContentSHA256Mismatch)
 		}
 		if !bytes.Equal(contentHashBytes, createdObj.HashSum) {
 			err = n.objectDelete(ctx, p.BktInfo, createdObj.ID)
 			if err != nil {
 				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", createdObj.ID))
 			}
-			return nil, apiErrors.GetAPIError(apiErrors.ErrContentSHA256Mismatch)
+			return nil, apierr.GetAPIError(apierr.ErrContentSHA256Mismatch)
 		}
 	}
 
@@ -398,19 +398,19 @@ func (n *Layer) headLastVersionIfNotDeleted(ctx context.Context, bkt *data.Bucke
 	node, err := n.treeService.GetLatestVersion(ctx, bkt, objectName)
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeNotFound) {
-			return nil, fmt.Errorf("%w: %s", apiErrors.GetAPIError(apiErrors.ErrNoSuchKey), err.Error())
+			return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error())
 		}
 		return nil, err
 	}
 
 	if node.IsDeleteMarker {
-		return nil, DeleteMarkerError{ErrorCode: apiErrors.ErrNoSuchKey}
+		return nil, DeleteMarkerError{ErrorCode: apierr.ErrNoSuchKey}
 	}
 
 	meta, err := n.objectHead(ctx, bkt, node.OID)
 	if err != nil {
 		if client.IsErrObjectNotFound(err) {
-			return nil, fmt.Errorf("%w: %s; %s", apiErrors.GetAPIError(apiErrors.ErrNoSuchKey), err.Error(), node.OID.EncodeToString())
+			return nil, fmt.Errorf("%w: %s; %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error(), node.OID.EncodeToString())
 		}
 		return nil, err
 	}
@@ -434,7 +434,7 @@ func (n *Layer) headVersion(ctx context.Context, bkt *data.BucketInfo, p *HeadOb
 		foundVersion, err = n.treeService.GetUnversioned(ctx, bkt, p.Object)
 		if err != nil {
 			if errors.Is(err, tree.ErrNodeNotFound) {
-				return nil, fmt.Errorf("%w: %s", apiErrors.GetAPIError(apiErrors.ErrNoSuchVersion), err.Error())
+				return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchVersion), err.Error())
 			}
 			return nil, err
 		}
@@ -451,7 +451,7 @@ func (n *Layer) headVersion(ctx context.Context, bkt *data.BucketInfo, p *HeadOb
 			}
 		}
 		if foundVersion == nil {
-			return nil, fmt.Errorf("%w: there isn't tree node with requested version id", apiErrors.GetAPIError(apiErrors.ErrNoSuchVersion))
+			return nil, fmt.Errorf("%w: there isn't tree node with requested version id", apierr.GetAPIError(apierr.ErrNoSuchVersion))
 		}
 	}
 
@@ -461,13 +461,13 @@ func (n *Layer) headVersion(ctx context.Context, bkt *data.BucketInfo, p *HeadOb
 	}
 
 	if foundVersion.IsDeleteMarker {
-		return nil, DeleteMarkerError{ErrorCode: apiErrors.ErrMethodNotAllowed}
+		return nil, DeleteMarkerError{ErrorCode: apierr.ErrMethodNotAllowed}
 	}
 
 	meta, err := n.objectHead(ctx, bkt, foundVersion.OID)
 	if err != nil {
 		if client.IsErrObjectNotFound(err) {
-			return nil, fmt.Errorf("%w: %s", apiErrors.GetAPIError(apiErrors.ErrNoSuchVersion), err.Error())
+			return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchVersion), err.Error())
 		}
 		return nil, err
 	}
diff --git a/api/layer/system_object.go b/api/layer/system_object.go
index 8ec5282..626d668 100644
--- a/api/layer/system_object.go
+++ b/api/layer/system_object.go
@@ -3,7 +3,7 @@ package layer
 import (
 	"context"
 	"encoding/xml"
-	errorsStd "errors"
+	"errors"
 	"fmt"
 	"math"
 	"strconv"
@@ -11,7 +11,7 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
@@ -42,7 +42,7 @@ func (n *Layer) PutLockInfo(ctx context.Context, p *PutLockInfoParams) (err erro
 	}
 
 	lockInfo, err := n.treeService.GetLock(ctx, p.ObjVersion.BktInfo, versionNode.ID)
-	if err != nil && !errorsStd.Is(err, tree.ErrNodeNotFound) {
+	if err != nil && !errors.Is(err, tree.ErrNodeNotFound) {
 		return err
 	}
 
@@ -148,7 +148,7 @@ func (n *Layer) GetLockInfo(ctx context.Context, objVersion *data.ObjectVersion)
 	}
 
 	lockInfo, err := n.treeService.GetLock(ctx, objVersion.BktInfo, versionNode.ID)
-	if err != nil && !errorsStd.Is(err, tree.ErrNodeNotFound) {
+	if err != nil && !errors.Is(err, tree.ErrNodeNotFound) {
 		return nil, err
 	}
 	if lockInfo == nil {
@@ -167,13 +167,13 @@ func (n *Layer) getCORS(ctx context.Context, bkt *data.BucketInfo) (*data.CORSCo
 	}
 
 	addr, err := n.treeService.GetBucketCORS(ctx, bkt)
-	objNotFound := errorsStd.Is(err, tree.ErrNodeNotFound)
+	objNotFound := errors.Is(err, tree.ErrNodeNotFound)
 	if err != nil && !objNotFound {
 		return nil, err
 	}
 
 	if objNotFound {
-		return nil, fmt.Errorf("%w: %s", errors.GetAPIError(errors.ErrNoSuchCORSConfiguration), err.Error())
+		return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchCORSConfiguration), err.Error())
 	}
 
 	var prmAuth frostfs.PrmAuth
@@ -211,7 +211,7 @@ func (n *Layer) GetBucketSettings(ctx context.Context, bktInfo *data.BucketInfo)
 
 	settings, err := n.treeService.GetSettingsNode(ctx, bktInfo)
 	if err != nil {
-		if !errorsStd.Is(err, tree.ErrNodeNotFound) {
+		if !errors.Is(err, tree.ErrNodeNotFound) {
 			return nil, err
 		}
 		settings = &data.BucketSettings{Versioning: data.VersioningUnversioned}
diff --git a/api/layer/tagging.go b/api/layer/tagging.go
index 2081096..a80e72b 100644
--- a/api/layer/tagging.go
+++ b/api/layer/tagging.go
@@ -6,7 +6,7 @@ import (
 	"fmt"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	s3errors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
@@ -41,7 +41,7 @@ func (n *Layer) GetObjectTagging(ctx context.Context, p *data.GetObjectTaggingPa
 	tags, err := n.treeService.GetObjectTagging(ctx, p.ObjectVersion.BktInfo, nodeVersion)
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeNotFound) {
-			return "", nil, fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchKey), err.Error())
+			return "", nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error())
 		}
 		return "", nil, err
 	}
@@ -64,7 +64,7 @@ func (n *Layer) PutObjectTagging(ctx context.Context, p *data.PutObjectTaggingPa
 	err = n.treeService.PutObjectTagging(ctx, p.ObjectVersion.BktInfo, nodeVersion, p.TagSet)
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeNotFound) {
-			return fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchKey), err.Error())
+			return fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error())
 		}
 		return err
 	}
@@ -83,7 +83,7 @@ func (n *Layer) DeleteObjectTagging(ctx context.Context, p *data.ObjectVersion)
 	err = n.treeService.DeleteObjectTagging(ctx, p.BktInfo, version)
 	if err != nil {
 		if errors.Is(err, tree.ErrNodeNotFound) {
-			return fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchKey), err.Error())
+			return fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error())
 		}
 		return err
 	}
@@ -156,14 +156,14 @@ func (n *Layer) getNodeVersion(ctx context.Context, objVersion *data.ObjectVersi
 			}
 		}
 		if version == nil {
-			err = fmt.Errorf("%w: there isn't tree node with requested version id", s3errors.GetAPIError(s3errors.ErrNoSuchVersion))
+			err = fmt.Errorf("%w: there isn't tree node with requested version id", apierr.GetAPIError(apierr.ErrNoSuchVersion))
 		}
 	}
 
 	if err == nil && version.IsDeleteMarker && !objVersion.NoErrorOnDeleteMarker {
-		return nil, fmt.Errorf("%w: found version is delete marker", s3errors.GetAPIError(s3errors.ErrNoSuchKey))
+		return nil, fmt.Errorf("%w: found version is delete marker", apierr.GetAPIError(apierr.ErrNoSuchKey))
 	} else if errors.Is(err, tree.ErrNodeNotFound) {
-		return nil, fmt.Errorf("%w: %s", s3errors.GetAPIError(s3errors.ErrNoSuchKey), err.Error())
+		return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrNoSuchKey), err.Error())
 	}
 
 	if err == nil && version != nil && !version.IsDeleteMarker {
diff --git a/api/middleware/auth.go b/api/middleware/auth.go
index c5318ca..998f3a1 100644
--- a/api/middleware/auth.go
+++ b/api/middleware/auth.go
@@ -8,9 +8,9 @@ import (
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/acl"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
-	frostfsErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
+	frosterr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
@@ -57,9 +57,10 @@ func Auth(center Center, log *zap.Logger) Func {
 					reqLogOrDefault(ctx, log).Debug(logs.CouldntReceiveAccessBoxForGateKeyRandomKeyWillBeUsed, zap.Error(err))
 				} else {
 					reqLogOrDefault(ctx, log).Error(logs.FailedToPassAuthentication, zap.Error(err))
-					err = frostfsErrors.UnwrapErr(err)
-					if _, ok := err.(apiErrors.Error); !ok {
-						err = apiErrors.GetAPIError(apiErrors.ErrAccessDenied)
+					err = frosterr.UnwrapErr(err)
+					log.Info("error", zap.Error(err), zap.String("code", err.(apierr.Error).Code), zap.String("description", err.(apierr.Error).Description))
+					if _, ok := err.(apierr.Error); !ok {
+						err = apierr.GetAPIError(apierr.ErrAccessDenied)
 					}
 					if _, wrErr := WriteErrorResponse(w, GetReqInfo(r.Context()), err); wrErr != nil {
 						reqLogOrDefault(ctx, log).Error(logs.FailedToWriteResponse, zap.Error(wrErr))
diff --git a/api/middleware/policy.go b/api/middleware/policy.go
index f3bcd63..109089a 100644
--- a/api/middleware/policy.go
+++ b/api/middleware/policy.go
@@ -11,7 +11,7 @@ import (
 	"strings"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	frostfsErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/logs"
 	"git.frostfs.info/TrueCloudLab/policy-engine/pkg/chain"
@@ -145,11 +145,11 @@ func policyCheck(r *http.Request, cfg PolicyConfig) error {
 	case st == chain.Allow:
 		return nil
 	case st != chain.NoRuleFound:
-		return apiErr.GetAPIErrorWithError(apiErr.ErrAccessDenied, fmt.Errorf("policy check: %s", st.String()))
+		return apierr.GetAPIErrorWithError(apierr.ErrAccessDenied, fmt.Errorf("policy check: %s", st.String()))
 	}
 
 	if cfg.Settings.PolicyDenyByDefault() {
-		return apiErr.GetAPIErrorWithError(apiErr.ErrAccessDenied, fmt.Errorf("policy check: %s", st.String()))
+		return apierr.GetAPIErrorWithError(apierr.ErrAccessDenied, fmt.Errorf("policy check: %s", st.String()))
 	}
 
 	return nil
@@ -461,7 +461,7 @@ func determineRequestTags(r *http.Request, decoder XMLDecoder, op string) (map[s
 	if strings.HasSuffix(op, PutObjectTaggingOperation) || strings.HasSuffix(op, PutBucketTaggingOperation) {
 		tagging := new(data.Tagging)
 		if err := decoder.NewXMLDecoder(r.Body).Decode(tagging); err != nil {
-			return nil, fmt.Errorf("%w: %s", apiErr.GetAPIError(apiErr.ErrMalformedXML), err.Error())
+			return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrMalformedXML), err.Error())
 		}
 		GetReqInfo(r.Context()).Tagging = tagging
 
@@ -473,7 +473,7 @@ func determineRequestTags(r *http.Request, decoder XMLDecoder, op string) (map[s
 	if tagging := r.Header.Get(amzTagging); len(tagging) > 0 {
 		queries, err := url.ParseQuery(tagging)
 		if err != nil {
-			return nil, apiErr.GetAPIError(apiErr.ErrInvalidArgument)
+			return nil, apierr.GetAPIError(apierr.ErrInvalidArgument)
 		}
 		for key := range queries {
 			tags[fmt.Sprintf(s3.PropertyKeyFormatRequestTag, key)] = queries.Get(key)
diff --git a/api/middleware/response.go b/api/middleware/response.go
index b94b403..94b633d 100644
--- a/api/middleware/response.go
+++ b/api/middleware/response.go
@@ -62,7 +62,7 @@ const (
 	hdrSSE = "X-Amz-Server-Side-Encryption"
 
 	// hdrSSECustomerKey is the HTTP header key referencing the
-	// SSE-C client-provided key..
+	// SSE-C client-provided key.
 	hdrSSECustomerKey = hdrSSE + "-Customer-Key"
 
 	// hdrSSECopyKey is the HTTP header key referencing the SSE-C
@@ -74,7 +74,7 @@ var (
 	xmlHeader = []byte(xml.Header)
 )
 
-// Non exhaustive list of AWS S3 standard error responses -
+// Non-exhaustive list of AWS S3 standard error responses -
 // http://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html
 var s3ErrorResponseMap = map[string]string{
 	"AccessDenied":                      "Access Denied.",
diff --git a/api/router_mock_test.go b/api/router_mock_test.go
index f2fd68e..817b0d4 100644
--- a/api/router_mock_test.go
+++ b/api/router_mock_test.go
@@ -10,7 +10,7 @@ import (
 	"testing"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/creds/accessbox"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
@@ -159,14 +159,14 @@ type resourceTaggingMock struct {
 
 func (m *resourceTaggingMock) GetBucketTagging(context.Context, *data.BucketInfo) (map[string]string, error) {
 	if m.noSuchBucketKey {
-		return nil, apiErrors.GetAPIError(apiErrors.ErrNoSuchKey)
+		return nil, apierr.GetAPIError(apierr.ErrNoSuchKey)
 	}
 	return m.bucketTags, nil
 }
 
 func (m *resourceTaggingMock) GetObjectTagging(context.Context, *data.GetObjectTaggingParams) (string, map[string]string, error) {
 	if m.noSuchObjectKey {
-		return "", nil, apiErrors.GetAPIError(apiErrors.ErrNoSuchKey)
+		return "", nil, apierr.GetAPIError(apierr.ErrNoSuchKey)
 	}
 	return "", m.objectTags, nil
 }
@@ -573,7 +573,7 @@ func (h *handlerMock) ResolveBucket(ctx context.Context, name string) (*data.Buc
 	reqInfo := middleware.GetReqInfo(ctx)
 	bktInfo, ok := h.buckets[reqInfo.Namespace+name]
 	if !ok {
-		return nil, apiErrors.GetAPIError(apiErrors.ErrNoSuchBucket)
+		return nil, apierr.GetAPIError(apierr.ErrNoSuchBucket)
 	}
 	return bktInfo, nil
 }
diff --git a/api/router_test.go b/api/router_test.go
index c6931b6..c4a524f 100644
--- a/api/router_test.go
+++ b/api/router_test.go
@@ -14,7 +14,7 @@ import (
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
-	apiErrors "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	apierr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
 	s3middleware "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/metrics"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
@@ -214,18 +214,18 @@ func TestPolicyChecker(t *testing.T) {
 	deleteObject(chiRouter, ns2, bktName2, objName2, nil)
 
 	// check we cannot access 'bucket' in custom namespace
-	putObjectErr(chiRouter, ns2, bktName1, objName2, nil, apiErrors.ErrAccessDenied)
-	deleteObjectErr(chiRouter, ns2, bktName1, objName2, nil, apiErrors.ErrAccessDenied)
+	putObjectErr(chiRouter, ns2, bktName1, objName2, nil, apierr.ErrAccessDenied)
+	deleteObjectErr(chiRouter, ns2, bktName1, objName2, nil, apierr.ErrAccessDenied)
 }
 
 func TestPolicyCheckerError(t *testing.T) {
 	chiRouter := prepareRouter(t)
 	ns1, bktName1, objName1 := "", "bucket", "object"
-	putObjectErr(chiRouter, ns1, bktName1, objName1, nil, apiErrors.ErrNoSuchBucket)
+	putObjectErr(chiRouter, ns1, bktName1, objName1, nil, apierr.ErrNoSuchBucket)
 
 	chiRouter = prepareRouter(t)
 	chiRouter.cfg.FrostfsID.(*frostFSIDMock).userGroupsError = true
-	putObjectErr(chiRouter, ns1, bktName1, objName1, nil, apiErrors.ErrInternalError)
+	putObjectErr(chiRouter, ns1, bktName1, objName1, nil, apierr.ErrInternalError)
 }
 
 func TestPolicyCheckerReqTypeDetermination(t *testing.T) {
@@ -283,7 +283,7 @@ func TestDefaultBehaviorPolicyChecker(t *testing.T) {
 
 	// check we cannot access if rules not found when settings is enabled
 	chiRouter.middlewareSettings.denyByDefault = true
-	createBucketErr(chiRouter, ns, bktName, nil, apiErrors.ErrAccessDenied)
+	createBucketErr(chiRouter, ns, bktName, nil, apierr.ErrAccessDenied)
 }
 
 func TestDefaultPolicyCheckerWithUserTags(t *testing.T) {
@@ -294,7 +294,7 @@ func TestDefaultPolicyCheckerWithUserTags(t *testing.T) {
 	allowOperations(router, ns, []string{"s3:CreateBucket"}, engineiam.Conditions{
 		engineiam.CondStringEquals: engineiam.Condition{fmt.Sprintf(common.PropertyKeyFormatFrostFSIDUserClaim, "tag-test"): []string{"test"}},
 	})
-	createBucketErr(router, ns, bktName, nil, apiErrors.ErrAccessDenied)
+	createBucketErr(router, ns, bktName, nil, apierr.ErrAccessDenied)
 
 	tags := make(map[string]string)
 	tags["tag-test"] = "test"
@@ -321,8 +321,8 @@ func TestRequestParametersCheck(t *testing.T) {
 		})
 
 		listObjectsV1(router, ns, bktName, prefix, "", "")
-		listObjectsV1Err(router, ns, bktName, "", "", "", apiErrors.ErrAccessDenied)
-		listObjectsV1Err(router, ns, bktName, "invalid", "", "", apiErrors.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "", "", "", apierr.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "invalid", "", "", apierr.ErrAccessDenied)
 	})
 
 	t.Run("delimiter parameter, prohibit specific value", func(t *testing.T) {
@@ -344,7 +344,7 @@ func TestRequestParametersCheck(t *testing.T) {
 
 		listObjectsV1(router, ns, bktName, "", "", "")
 		listObjectsV1(router, ns, bktName, "", "some-delimiter", "")
-		listObjectsV1Err(router, ns, bktName, "", delimiter, "", apiErrors.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "", delimiter, "", apierr.ErrAccessDenied)
 	})
 
 	t.Run("max-keys parameter, allow specific value", func(t *testing.T) {
@@ -365,9 +365,9 @@ func TestRequestParametersCheck(t *testing.T) {
 		})
 
 		listObjectsV1(router, ns, bktName, "", "", strconv.Itoa(maxKeys))
-		listObjectsV1Err(router, ns, bktName, "", "", "", apiErrors.ErrAccessDenied)
-		listObjectsV1Err(router, ns, bktName, "", "", strconv.Itoa(maxKeys-1), apiErrors.ErrAccessDenied)
-		listObjectsV1Err(router, ns, bktName, "", "", "invalid", apiErrors.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "", "", "", apierr.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "", "", strconv.Itoa(maxKeys-1), apierr.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "", "", "invalid", apierr.ErrAccessDenied)
 	})
 
 	t.Run("max-keys parameter, allow range of values", func(t *testing.T) {
@@ -389,7 +389,7 @@ func TestRequestParametersCheck(t *testing.T) {
 
 		listObjectsV1(router, ns, bktName, "", "", strconv.Itoa(maxKeys))
 		listObjectsV1(router, ns, bktName, "", "", strconv.Itoa(maxKeys-1))
-		listObjectsV1Err(router, ns, bktName, "", "", strconv.Itoa(maxKeys+1), apiErrors.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "", "", strconv.Itoa(maxKeys+1), apierr.ErrAccessDenied)
 	})
 
 	t.Run("max-keys parameter, prohibit specific value", func(t *testing.T) {
@@ -411,7 +411,7 @@ func TestRequestParametersCheck(t *testing.T) {
 
 		listObjectsV1(router, ns, bktName, "", "", "")
 		listObjectsV1(router, ns, bktName, "", "", strconv.Itoa(maxKeys-1))
-		listObjectsV1Err(router, ns, bktName, "", "", strconv.Itoa(maxKeys), apiErrors.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "", "", strconv.Itoa(maxKeys), apierr.ErrAccessDenied)
 	})
 }
 
@@ -439,10 +439,10 @@ func TestRequestTagsCheck(t *testing.T) {
 
 		tagging, err = xml.Marshal(data.Tagging{TagSet: []data.Tag{{Key: "key", Value: tagValue}}})
 		require.NoError(t, err)
-		putBucketTaggingErr(router, ns, bktName, tagging, apiErrors.ErrAccessDenied)
+		putBucketTaggingErr(router, ns, bktName, tagging, apierr.ErrAccessDenied)
 
 		tagging = nil
-		putBucketTaggingErr(router, ns, bktName, tagging, apiErrors.ErrMalformedXML)
+		putBucketTaggingErr(router, ns, bktName, tagging, apierr.ErrMalformedXML)
 	})
 
 	t.Run("put object with tag", func(t *testing.T) {
@@ -464,7 +464,7 @@ func TestRequestTagsCheck(t *testing.T) {
 
 		putObject(router, ns, bktName, objName, &data.Tag{Key: tagKey, Value: tagValue})
 
-		putObjectErr(router, ns, bktName, objName, &data.Tag{Key: "key", Value: tagValue}, apiErrors.ErrAccessDenied)
+		putObjectErr(router, ns, bktName, objName, &data.Tag{Key: "key", Value: tagValue}, apierr.ErrAccessDenied)
 	})
 }
 
@@ -490,7 +490,7 @@ func TestResourceTagsCheck(t *testing.T) {
 		listObjectsV1(router, ns, bktName, "", "", "")
 
 		router.cfg.Tagging.(*resourceTaggingMock).bucketTags = map[string]string{}
-		listObjectsV1Err(router, ns, bktName, "", "", "", apiErrors.ErrAccessDenied)
+		listObjectsV1Err(router, ns, bktName, "", "", "", apierr.ErrAccessDenied)
 	})
 
 	t.Run("object tagging", func(t *testing.T) {
@@ -515,22 +515,22 @@ func TestResourceTagsCheck(t *testing.T) {
 		getObject(router, ns, bktName, objName)
 
 		router.cfg.Tagging.(*resourceTaggingMock).objectTags = map[string]string{}
-		getObjectErr(router, ns, bktName, objName, apiErrors.ErrAccessDenied)
+		getObjectErr(router, ns, bktName, objName, apierr.ErrAccessDenied)
 	})
 
 	t.Run("non-existent resources", func(t *testing.T) {
 		router := prepareRouter(t)
 		ns, bktName, objName := "", "bucket", "object"
 
-		listObjectsV1Err(router, ns, bktName, "", "", "", apiErrors.ErrNoSuchBucket)
+		listObjectsV1Err(router, ns, bktName, "", "", "", apierr.ErrNoSuchBucket)
 
 		router.cfg.Tagging.(*resourceTaggingMock).noSuchBucketKey = true
 		createBucket(router, ns, bktName)
-		getBucketErr(router, ns, bktName, apiErrors.ErrNoSuchKey)
+		getBucketErr(router, ns, bktName, apierr.ErrNoSuchKey)
 
 		router.cfg.Tagging.(*resourceTaggingMock).noSuchObjectKey = true
 		createBucket(router, ns, bktName)
-		getObjectErr(router, ns, bktName, objName, apiErrors.ErrNoSuchKey)
+		getObjectErr(router, ns, bktName, objName, apierr.ErrNoSuchKey)
 	})
 }
 
@@ -548,7 +548,7 @@ func TestAccessBoxAttributesCheck(t *testing.T) {
 		engineiam.CondBool: engineiam.Condition{fmt.Sprintf(s3.PropertyKeyFormatAccessBoxAttr, attrKey): []string{attrValue}},
 	})
 
-	listObjectsV1Err(router, ns, bktName, "", "", "", apiErrors.ErrAccessDenied)
+	listObjectsV1Err(router, ns, bktName, "", "", "", apierr.ErrAccessDenied)
 
 	var attr object.Attribute
 	attr.SetKey(attrKey)
@@ -570,7 +570,7 @@ func TestSourceIPCheck(t *testing.T) {
 
 	router.middlewareSettings.sourceIPHeader = hdr
 	header := map[string][]string{hdr: {"192.0.3.0"}}
-	createBucketErr(router, ns, bktName, header, apiErrors.ErrAccessDenied)
+	createBucketErr(router, ns, bktName, header, apierr.ErrAccessDenied)
 
 	router.middlewareSettings.sourceIPHeader = ""
 	createBucket(router, ns, bktName)
@@ -586,7 +586,7 @@ func TestMFAPolicy(t *testing.T) {
 	denyOperations(router, ns, []string{"s3:CreateBucket"}, engineiam.Conditions{
 		engineiam.CondBool: engineiam.Condition{s3.PropertyKeyAccessBoxAttrMFA: []string{"false"}},
 	})
-	createBucketErr(router, ns, bktName, nil, apiErrors.ErrAccessDenied)
+	createBucketErr(router, ns, bktName, nil, apierr.ErrAccessDenied)
 
 	var attr object.Attribute
 	attr.SetKey("IAM-MFA")
@@ -630,7 +630,7 @@ func createBucket(router *routerMock, namespace, bktName string) {
 	require.Equal(router.t, s3middleware.CreateBucketOperation, resp.Method)
 }
 
-func createBucketErr(router *routerMock, namespace, bktName string, header http.Header, errCode apiErrors.ErrorCode) {
+func createBucketErr(router *routerMock, namespace, bktName string, header http.Header, errCode apierr.ErrorCode) {
 	w := createBucketBase(router, namespace, bktName, header)
 	assertAPIError(router.t, w, errCode)
 }
@@ -646,7 +646,7 @@ func createBucketBase(router *routerMock, namespace, bktName string, header http
 	return w
 }
 
-func getBucketErr(router *routerMock, namespace, bktName string, errCode apiErrors.ErrorCode) {
+func getBucketErr(router *routerMock, namespace, bktName string, errCode apierr.ErrorCode) {
 	w := getBucketBase(router, namespace, bktName)
 	assertAPIError(router.t, w, errCode)
 }
@@ -665,7 +665,7 @@ func putObject(router *routerMock, namespace, bktName, objName string, tag *data
 	return resp
 }
 
-func putObjectErr(router *routerMock, namespace, bktName, objName string, tag *data.Tag, errCode apiErrors.ErrorCode) {
+func putObjectErr(router *routerMock, namespace, bktName, objName string, tag *data.Tag, errCode apierr.ErrorCode) {
 	w := putObjectBase(router, namespace, bktName, objName, tag)
 	assertAPIError(router.t, w, errCode)
 }
@@ -690,7 +690,7 @@ func deleteObject(router *routerMock, namespace, bktName, objName string, tag *d
 	return resp
 }
 
-func deleteObjectErr(router *routerMock, namespace, bktName, objName string, tag *data.Tag, errCode apiErrors.ErrorCode) {
+func deleteObjectErr(router *routerMock, namespace, bktName, objName string, tag *data.Tag, errCode apierr.ErrorCode) {
 	w := deleteObjectBase(router, namespace, bktName, objName, tag)
 	assertAPIError(router.t, w, errCode)
 }
@@ -715,7 +715,7 @@ func putBucketTagging(router *routerMock, namespace, bktName string, tagging []b
 	return resp
 }
 
-func putBucketTaggingErr(router *routerMock, namespace, bktName string, tagging []byte, errCode apiErrors.ErrorCode) {
+func putBucketTaggingErr(router *routerMock, namespace, bktName string, tagging []byte, errCode apierr.ErrorCode) {
 	w := putBucketTaggingBase(router, namespace, bktName, tagging)
 	assertAPIError(router.t, w, errCode)
 }
@@ -738,7 +738,7 @@ func getObject(router *routerMock, namespace, bktName, objName string) handlerRe
 	return resp
 }
 
-func getObjectErr(router *routerMock, namespace, bktName, objName string, errCode apiErrors.ErrorCode) {
+func getObjectErr(router *routerMock, namespace, bktName, objName string, errCode apierr.ErrorCode) {
 	w := getObjectBase(router, namespace, bktName, objName)
 	assertAPIError(router.t, w, errCode)
 }
@@ -757,7 +757,7 @@ func listObjectsV1(router *routerMock, namespace, bktName, prefix, delimiter, ma
 	return resp
 }
 
-func listObjectsV1Err(router *routerMock, namespace, bktName, prefix, delimiter, maxKeys string, errCode apiErrors.ErrorCode) {
+func listObjectsV1Err(router *routerMock, namespace, bktName, prefix, delimiter, maxKeys string, errCode apierr.ErrorCode) {
 	w := listObjectsV1Base(router, namespace, bktName, prefix, delimiter, maxKeys)
 	assertAPIError(router.t, w, errCode)
 }
@@ -827,7 +827,7 @@ func TestAuthenticate(t *testing.T) {
 
 	chiRouter = prepareRouter(t)
 	chiRouter.cfg.Center.(*centerMock).isError = true
-	createBucketErr(chiRouter, "", "bkt-3", nil, apiErrors.ErrAccessDenied)
+	createBucketErr(chiRouter, "", "bkt-3", nil, apierr.ErrAccessDenied)
 }
 
 func TestFrostFSIDValidation(t *testing.T) {
@@ -843,7 +843,7 @@ func TestFrostFSIDValidation(t *testing.T) {
 	// frostFSID validation failed
 	chiRouter = prepareRouter(t, frostFSIDValidation(true))
 	chiRouter.cfg.FrostfsID.(*frostFSIDMock).validateError = true
-	createBucketErr(chiRouter, "", "bkt-3", nil, apiErrors.ErrInternalError)
+	createBucketErr(chiRouter, "", "bkt-3", nil, apierr.ErrInternalError)
 }
 
 func TestRouterListObjectsV2Domains(t *testing.T) {
@@ -882,17 +882,17 @@ func readResponse(t *testing.T, w *httptest.ResponseRecorder) handlerResult {
 	return res
 }
 
-func assertAPIError(t *testing.T, w *httptest.ResponseRecorder, expectedErrorCode apiErrors.ErrorCode) {
+func assertAPIError(t *testing.T, w *httptest.ResponseRecorder, expectedErrorCode apierr.ErrorCode) {
 	actualErrorResponse := &s3middleware.ErrorResponse{}
 	err := xml.NewDecoder(w.Result().Body).Decode(actualErrorResponse)
 	require.NoError(t, err)
 
-	expectedError := apiErrors.GetAPIError(expectedErrorCode)
+	expectedError := apierr.GetAPIError(expectedErrorCode)
 
 	require.Equal(t, expectedError.HTTPStatusCode, w.Code)
 	require.Equal(t, expectedError.Code, actualErrorResponse.Code)
 
-	if expectedError.ErrCode != apiErrors.ErrInternalError {
+	if expectedError.ErrCode != apierr.ErrInternalError {
 		require.Contains(t, actualErrorResponse.Message, expectedError.Description)
 	}
 }
diff --git a/internal/frostfs/frostfs.go b/internal/frostfs/frostfs.go
index 9651854..95ac17b 100644
--- a/internal/frostfs/frostfs.go
+++ b/internal/frostfs/frostfs.go
@@ -11,7 +11,7 @@ import (
 
 	objectv2 "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
-	errorsFrost "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
+	frosterr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
@@ -466,11 +466,11 @@ func handleObjectError(msg string, err error) error {
 		return nil
 	}
 
-	if reason, ok := errorsFrost.IsErrObjectAccessDenied(err); ok {
+	if reason, ok := frosterr.IsErrObjectAccessDenied(err); ok {
 		return fmt.Errorf("%s: %w: %s", msg, frostfs.ErrAccessDenied, reason)
 	}
 
-	if errorsFrost.IsTimeoutError(err) {
+	if frosterr.IsTimeoutError(err) {
 		return fmt.Errorf("%s: %w: %s", msg, frostfs.ErrGatewayTimeout, err.Error())
 	}
 
diff --git a/internal/frostfs/frostfs_test.go b/internal/frostfs/frostfs_test.go
index 137832a..ef5d9ca 100644
--- a/internal/frostfs/frostfs_test.go
+++ b/internal/frostfs/frostfs_test.go
@@ -8,7 +8,7 @@ import (
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/frostfs"
-	errorsFrost "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
+	frosterr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
 	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
 	"github.com/stretchr/testify/require"
 	"google.golang.org/grpc/codes"
@@ -22,7 +22,7 @@ func TestErrorChecking(t *testing.T) {
 
 	var wrappedError error
 
-	if fetchedReason, ok := errorsFrost.IsErrObjectAccessDenied(err); ok {
+	if fetchedReason, ok := frosterr.IsErrObjectAccessDenied(err); ok {
 		wrappedError = fmt.Errorf("%w: %s", frostfs.ErrAccessDenied, fetchedReason)
 	}
 
@@ -32,7 +32,7 @@ func TestErrorChecking(t *testing.T) {
 
 func TestErrorTimeoutChecking(t *testing.T) {
 	t.Run("simple timeout", func(t *testing.T) {
-		require.True(t, errorsFrost.IsTimeoutError(errors.New("timeout")))
+		require.True(t, frosterr.IsTimeoutError(errors.New("timeout")))
 	})
 
 	t.Run("deadline exceeded", func(t *testing.T) {
@@ -40,11 +40,11 @@ func TestErrorTimeoutChecking(t *testing.T) {
 		defer cancel()
 		<-ctx.Done()
 
-		require.True(t, errorsFrost.IsTimeoutError(ctx.Err()))
+		require.True(t, frosterr.IsTimeoutError(ctx.Err()))
 	})
 
 	t.Run("grpc deadline exceeded", func(t *testing.T) {
 		err := fmt.Errorf("wrap grpc error: %w", status.Error(codes.DeadlineExceeded, "error"))
-		require.True(t, errorsFrost.IsTimeoutError(err))
+		require.True(t, frosterr.IsTimeoutError(err))
 	})
 }
diff --git a/internal/frostfs/services/pool_wrapper.go b/internal/frostfs/services/pool_wrapper.go
index a96b198..8128de4 100644
--- a/internal/frostfs/services/pool_wrapper.go
+++ b/internal/frostfs/services/pool_wrapper.go
@@ -8,15 +8,15 @@ import (
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
-	errorsFrost "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
+	frosterr "git.frostfs.info/TrueCloudLab/frostfs-s3-gw/internal/frostfs/errors"
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/pkg/service/tree"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
 	treepool "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool/tree"
-	grpcService "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool/tree/service"
+	grpcservice "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool/tree/service"
 )
 
 type GetNodeByPathResponseInfoWrapper struct {
-	response *grpcService.GetNodeByPathResponse_Info
+	response *grpcservice.GetNodeByPathResponse_Info
 }
 
 func (n GetNodeByPathResponseInfoWrapper) GetNodeID() []uint64 {
@@ -40,7 +40,7 @@ func (n GetNodeByPathResponseInfoWrapper) GetMeta() []tree.Meta {
 }
 
 type GetSubTreeResponseBodyWrapper struct {
-	response *grpcService.GetSubTreeResponse_Body
+	response *grpcservice.GetSubTreeResponse_Body
 }
 
 func (n GetSubTreeResponseBodyWrapper) GetNodeID() []uint64 {
@@ -144,7 +144,7 @@ func (w *PoolWrapper) GetSubTree(ctx context.Context, bktInfo *data.BucketInfo,
 
 type SubTreeStreamImpl struct {
 	r      *treepool.SubTreeReader
-	buffer []*grpcService.GetSubTreeResponse_Body
+	buffer []*grpcservice.GetSubTreeResponse_Body
 	eof    bool
 	index  int
 	ln     int
@@ -204,7 +204,7 @@ func (w *PoolWrapper) GetSubTreeStream(ctx context.Context, bktInfo *data.Bucket
 
 	return &SubTreeStreamImpl{
 		r:      subTreeReader,
-		buffer: make([]*grpcService.GetSubTreeResponse_Body, bufSize),
+		buffer: make([]*grpcservice.GetSubTreeResponse_Body, bufSize),
 		index:  -1,
 	}, nil
 }
@@ -273,7 +273,7 @@ func handleError(err error) error {
 	if errors.Is(err, treepool.ErrNodeAccessDenied) {
 		return fmt.Errorf("%w: %s", tree.ErrNodeAccessDenied, err.Error())
 	}
-	if errorsFrost.IsTimeoutError(err) {
+	if frosterr.IsTimeoutError(err) {
 		return fmt.Errorf("%w: %s", tree.ErrGatewayTimeout, err.Error())
 	}
 
diff --git a/pkg/service/tree/tree.go b/pkg/service/tree/tree.go
index 0b095a0..438b129 100644
--- a/pkg/service/tree/tree.go
+++ b/pkg/service/tree/tree.go
@@ -978,7 +978,7 @@ func (s *VersionsByPrefixStreamImpl) getNodeFromMainStream() (NodeResponse, erro
 	for {
 		node, err := s.mainStream.Next()
 		if err != nil {
-			if errors.Is(err, ErrNodeNotFound) {
+			if errors.Is(err, tree.ErrNodeNotFound) {
 				return nil, io.EOF
 			}
 			return nil, fmt.Errorf("main stream next: %w", err)
diff --git a/pkg/service/tree/tree_client_in_memory.go b/pkg/service/tree/tree_client_in_memory.go
index 4c27fd7..efa93c4 100644
--- a/pkg/service/tree/tree_client_in_memory.go
+++ b/pkg/service/tree/tree_client_in_memory.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
+	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer/tree"
 	"golang.org/x/exp/slices"
 )
 
@@ -242,7 +243,7 @@ func (c *ServiceClientMemory) GetSubTree(_ context.Context, bktInfo *data.Bucket
 
 	tr, ok := cnr.trees[treeID]
 	if !ok {
-		return nil, ErrNodeNotFound
+		return nil, tree.ErrNodeNotFound
 	}
 
 	if len(rootID) != 1 {
@@ -251,7 +252,7 @@ func (c *ServiceClientMemory) GetSubTree(_ context.Context, bktInfo *data.Bucket
 
 	node := tr.treeData.getNode(rootID[0])
 	if node == nil {
-		return nil, ErrNodeNotFound
+		return nil, tree.ErrNodeNotFound
 	}
 
 	if sort {
@@ -282,12 +283,12 @@ func (s *SubTreeStreamMemoryImpl) Next() (NodeResponse, error) {
 func (c *ServiceClientMemory) GetSubTreeStream(_ context.Context, bktInfo *data.BucketInfo, treeID string, rootID []uint64, depth uint32) (SubTreeStream, error) {
 	cnr, ok := c.containers[bktInfo.CID.EncodeToString()]
 	if !ok {
-		return &SubTreeStreamMemoryImpl{err: ErrNodeNotFound}, nil
+		return &SubTreeStreamMemoryImpl{err: tree.ErrNodeNotFound}, nil
 	}
 
 	tr, ok := cnr.trees[treeID]
 	if !ok {
-		return nil, ErrNodeNotFound
+		return nil, tree.ErrNodeNotFound
 	}
 
 	if len(rootID) != 1 {
@@ -296,7 +297,7 @@ func (c *ServiceClientMemory) GetSubTreeStream(_ context.Context, bktInfo *data.
 
 	node := tr.treeData.getNode(rootID[0])
 	if node == nil {
-		return nil, ErrNodeNotFound
+		return nil, tree.ErrNodeNotFound
 	}
 
 	sortNode(tr.treeData)
@@ -353,7 +354,7 @@ func (c *ServiceClientMemory) AddNodeBase(_ context.Context, bktInfo *data.Bucke
 
 	parentNode := tr.treeData.getNode(parent)
 	if parentNode == nil {
-		return 0, ErrNodeNotFound
+		return 0, tree.ErrNodeNotFound
 	}
 
 	newID := tr.idCounter
@@ -418,22 +419,22 @@ func (c *ServiceClientMemory) AddNodeByPath(_ context.Context, bktInfo *data.Buc
 func (c *ServiceClientMemory) MoveNode(_ context.Context, bktInfo *data.BucketInfo, treeID string, nodeID, parentID uint64, meta map[string]string) error {
 	cnr, ok := c.containers[bktInfo.CID.EncodeToString()]
 	if !ok {
-		return ErrNodeNotFound
+		return tree.ErrNodeNotFound
 	}
 
 	tr, ok := cnr.trees[treeID]
 	if !ok {
-		return ErrNodeNotFound
+		return tree.ErrNodeNotFound
 	}
 
 	node := tr.treeData.getNode(nodeID)
 	if node == nil {
-		return ErrNodeNotFound
+		return tree.ErrNodeNotFound
 	}
 
 	newParent := tr.treeData.getNode(parentID)
 	if newParent == nil {
-		return ErrNodeNotFound
+		return tree.ErrNodeNotFound
 	}
 
 	node.data.meta = metaToNodeMeta(meta)
@@ -466,17 +467,17 @@ func sortNodes(list []*treeNodeMemory) {
 func (c *ServiceClientMemory) RemoveNode(_ context.Context, bktInfo *data.BucketInfo, treeID string, nodeID uint64) error {
 	cnr, ok := c.containers[bktInfo.CID.EncodeToString()]
 	if !ok {
-		return ErrNodeNotFound
+		return tree.ErrNodeNotFound
 	}
 
 	tr, ok := cnr.trees[treeID]
 	if !ok {
-		return ErrNodeNotFound
+		return tree.ErrNodeNotFound
 	}
 
 	node := tr.treeData.getNode(nodeID)
 	if node == nil {
-		return ErrNodeNotFound
+		return tree.ErrNodeNotFound
 	}
 
 	node.parent.removeChild(nodeID)