diff --git a/goextVersion.go b/goextVersion.go
index b276897..6cf06cb 100644
--- a/goextVersion.go
+++ b/goextVersion.go
@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.447"
+const GoextVersion = "0.0.448"
 
-const GoextVersionTimestamp = "2024-05-10T21:33:01+0200"
+const GoextVersionTimestamp = "2024-05-12T16:45:45+0200"
diff --git a/wmo/collection.go b/wmo/collection.go
index bbfdc27..b638ac9 100644
--- a/wmo/collection.go
+++ b/wmo/collection.go
@@ -52,6 +52,7 @@ type Coll[TData any] struct {
 	customDecoder       *func(ctx context.Context, dec Decodable) (TData, error) // custom decoding function (useful if TData is an interface)
 	isInterfaceDataType bool                                                     // true if TData is an interface (not a struct)
 	unmarshalHooks      []func(d TData) TData                                    // called for every object after unmarshalling
+	marshalHooks        []func(d TData) TData                                    // called for every object before marshalling
 	extraModPipeline    []func(ctx context.Context) mongo.Pipeline               // appended to pipelines after filter/limit/skip/sort, used for $lookup, $set, $unset, $project, etc
 }
 
@@ -83,18 +84,32 @@ func (c *Coll[TData]) WithDecodeFunc(cdf func(ctx context.Context, dec Decodable
 	return c
 }
 
+// WithUnmarshalHook
+// function that is called for every object after reading from DB
 func (c *Coll[TData]) WithUnmarshalHook(fn func(d TData) TData) *Coll[TData] {
 	c.unmarshalHooks = append(c.unmarshalHooks, fn)
 
 	return c
 }
 
+// WithMarshalHook
+// function that is called for every object before writing to DB
+func (c *Coll[TData]) WithMarshalHook(fn func(d TData) TData) *Coll[TData] {
+	c.extraModPipeline = append(c.marshalHooks, fn)
+
+	return c
+}
+
+// WithModifyingPipeline
+// pipeline that is appended to all read operations (after filtering)
 func (c *Coll[TData]) WithModifyingPipeline(p mongo.Pipeline) *Coll[TData] {
 	c.extraModPipeline = append(c.extraModPipeline, func(ctx context.Context) mongo.Pipeline { return p })
 
 	return c
 }
 
+// WithModifyingPipelineFunc
+// pipeline that is appended to all read operations (after filtering)
 func (c *Coll[TData]) WithModifyingPipelineFunc(fn func(ctx context.Context) mongo.Pipeline) *Coll[TData] {
 	c.extraModPipeline = append(c.extraModPipeline, fn)
 
diff --git a/wmo/queryInsert.go b/wmo/queryInsert.go
index ef76014..3e8bdc3 100644
--- a/wmo/queryInsert.go
+++ b/wmo/queryInsert.go
@@ -9,6 +9,10 @@ import (
 )
 
 func (c *Coll[TData]) InsertOne(ctx context.Context, valueIn TData) (TData, error) {
+	for _, hook := range c.marshalHooks {
+		valueIn = hook(valueIn)
+	}
+
 	insRes, err := c.coll.InsertOne(ctx, valueIn)
 	if err != nil {
 		return *new(TData), exerr.Wrap(err, "mongo-query[insert-one] failed").Str("collection", c.Name()).Build()
@@ -36,6 +40,12 @@ func (c *Coll[TData]) InsertOneUnchecked(ctx context.Context, valueIn any) (TDat
 }
 
 func (c *Coll[TData]) InsertMany(ctx context.Context, valueIn []TData) (*mongo.InsertManyResult, error) {
+	for _, hook := range c.marshalHooks {
+		for i := 0; i < len(valueIn); i++ {
+			valueIn[i] = hook(valueIn[i])
+		}
+	}
+
 	insRes, err := c.coll.InsertMany(ctx, langext.ArrayToInterface(valueIn))
 	if err != nil {
 		return nil, exerr.Wrap(err, "mongo-query[insert-many] failed").Int("len(valueIn)", len(valueIn)).Str("collection", c.Name()).Build()
diff --git a/wmo/queryUpdate.go b/wmo/queryUpdate.go
index 6a6bd8c..8cafea1 100644
--- a/wmo/queryUpdate.go
+++ b/wmo/queryUpdate.go
@@ -61,6 +61,10 @@ func (c *Coll[TData]) UpdateMany(ctx context.Context, filterQuery bson.M, update
 }
 
 func (c *Coll[TData]) ReplaceOne(ctx context.Context, filterQuery bson.M, value TData) error {
+	for _, hook := range c.marshalHooks {
+		value = hook(value)
+	}
+
 	_, err := c.coll.UpdateOne(ctx, filterQuery, bson.M{"$set": value})
 	if err != nil {
 		return exerr.Wrap(err, "mongo-query[replace-one] failed").
@@ -73,6 +77,10 @@ func (c *Coll[TData]) ReplaceOne(ctx context.Context, filterQuery bson.M, value
 }
 
 func (c *Coll[TData]) FindOneAndReplace(ctx context.Context, filterQuery bson.M, value TData) (TData, error) {
+	for _, hook := range c.marshalHooks {
+		value = hook(value)
+	}
+
 	mongoRes := c.coll.FindOneAndReplace(ctx, filterQuery, value, options.FindOneAndReplace().SetReturnDocument(options.After))
 	if err := mongoRes.Err(); err != nil {
 		return *new(TData), exerr.Wrap(err, "mongo-query[find-one-and-update] failed").