diff --git a/api/request.param.go b/api/request.param.go
index ae1073c..10b53b4 100644
--- a/api/request.param.go
+++ b/api/request.param.go
@@ -2,15 +2,21 @@ package api
 
 import (
 	"fmt"
-
-	"git.xdrm.io/go/aicra/internal/cerr"
 )
 
+// Error allows you to create constant "const" error with type boxing.
+type Error string
+
+// Error implements the error builtin interface.
+func (err Error) Error() string {
+	return string(err)
+}
+
 // ErrReqParamNotFound is thrown when a request parameter is not found
-const ErrReqParamNotFound = cerr.Error("request parameter not found")
+const ErrReqParamNotFound = Error("request parameter not found")
 
 // ErrReqParamNotType is thrown when a request parameter is not asked with the right type
-const ErrReqParamNotType = cerr.Error("request parameter does not fulfills type")
+const ErrReqParamNotType = Error("request parameter does not fulfills type")
 
 // RequestParam defines input parameters of an api request
 type RequestParam map[string]interface{}
diff --git a/internal/cerr/cerr.go b/internal/cerr/cerr.go
deleted file mode 100644
index 19a8e6d..0000000
--- a/internal/cerr/cerr.go
+++ /dev/null
@@ -1,36 +0,0 @@
-package cerr
-
-// Error allows you to create constant "const" error with type boxing.
-type Error string
-
-// Error implements the error builtin interface.
-func (err Error) Error() string {
-	return string(err)
-}
-
-// Wrap returns a new error which wraps a new error into itself.
-func (err Error) Wrap(e error) *WrapError {
-	return &WrapError{
-		base: err,
-		wrap: e,
-	}
-}
-
-// WrapString returns a new error which wraps a new error created from a string.
-func (err Error) WrapString(e string) *WrapError {
-	return &WrapError{
-		base: err,
-		wrap: Error(e),
-	}
-}
-
-// WrapError is way to wrap errors recursively.
-type WrapError struct {
-	base error
-	wrap error
-}
-
-// Error implements the error builtin interface recursively.
-func (err *WrapError) Error() string {
-	return err.base.Error() + ": " + err.wrap.Error()
-}
diff --git a/internal/cerr/cerr_test.go b/internal/cerr/cerr_test.go
deleted file mode 100644
index 476996c..0000000
--- a/internal/cerr/cerr_test.go
+++ /dev/null
@@ -1,57 +0,0 @@
-package cerr
-
-import (
-	"errors"
-	"fmt"
-	"testing"
-)
-
-func TestConstError(t *testing.T) {
-	const cerr1 = Error("some-string")
-	const cerr2 = Error("some-other-string")
-	const cerr3 = Error("some-string") // same const value as @cerr1
-
-	if cerr1.Error() == cerr2.Error() {
-		t.Errorf("cerr1 should not be equal to cerr2 ('%s', '%s')", cerr1.Error(), cerr2.Error())
-	}
-	if cerr2.Error() == cerr3.Error() {
-		t.Errorf("cerr2 should not be equal to cerr3 ('%s', '%s')", cerr2.Error(), cerr3.Error())
-	}
-	if cerr1.Error() != cerr3.Error() {
-		t.Errorf("cerr1 should be equal to cerr3 ('%s', '%s')", cerr1.Error(), cerr3.Error())
-	}
-}
-
-func TestWrappedConstError(t *testing.T) {
-	const parent = Error("file error")
-
-	const readErrorConst = Error("cannot read file")
-	var wrappedReadError = parent.Wrap(readErrorConst)
-
-	expectedWrappedReadError := fmt.Sprintf("%s: %s", parent.Error(), readErrorConst.Error())
-	if wrappedReadError.Error() != expectedWrappedReadError {
-		t.Errorf("expected '%s' (got '%s')", wrappedReadError.Error(), expectedWrappedReadError)
-	}
-}
-func TestWrappedStandardError(t *testing.T) {
-	const parent = Error("file error")
-
-	var writeErrorStandard error = errors.New("cannot write file")
-	var wrappedWriteError = parent.Wrap(writeErrorStandard)
-
-	expectedWrappedWriteError := fmt.Sprintf("%s: %s", parent.Error(), writeErrorStandard.Error())
-	if wrappedWriteError.Error() != expectedWrappedWriteError {
-		t.Errorf("expected '%s' (got '%s')", wrappedWriteError.Error(), expectedWrappedWriteError)
-	}
-}
-func TestWrappedStringError(t *testing.T) {
-	const parent = Error("file error")
-
-	var closeErrorString string = "cannot close file"
-	var wrappedCloseError = parent.WrapString(closeErrorString)
-
-	expectedWrappedCloseError := fmt.Sprintf("%s: %s", parent.Error(), closeErrorString)
-	if wrappedCloseError.Error() != expectedWrappedCloseError {
-		t.Errorf("expected '%s' (got '%s')", wrappedCloseError.Error(), expectedWrappedCloseError)
-	}
-}
diff --git a/internal/multipart/types.go b/internal/multipart/types.go
index 86fda25..83c46f8 100644
--- a/internal/multipart/types.go
+++ b/internal/multipart/types.go
@@ -1,15 +1,21 @@
 package multipart
 
-import "git.xdrm.io/go/aicra/internal/cerr"
+// Error allows you to create constant "const" error with type boxing.
+type Error string
+
+// Error implements the error builtin interface.
+func (err Error) Error() string {
+	return string(err)
+}
 
 // ErrMissingDataName is set when a multipart variable/file has no name="..."
-const ErrMissingDataName = cerr.Error("data has no name")
+const ErrMissingDataName = Error("data has no name")
 
 // ErrDataNameConflict is set when a multipart variable/file name is already used
-const ErrDataNameConflict = cerr.Error("data name conflict")
+const ErrDataNameConflict = Error("data name conflict")
 
 // ErrNoHeader is set when a multipart variable/file has no (valid) header
-const ErrNoHeader = cerr.Error("data has no header")
+const ErrNoHeader = Error("data has no header")
 
 // Component represents a multipart variable/file
 type Component struct {