diff --git a/README.md b/README.md
index e5dcf113..bcb68ea1 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@ This SDK provides the interfaces to implement [Numaflow](https://github.com/numa
 Source Transformer, Functions, Sinks or SideInputs in Golang.
 - Implement [User Defined Sources](https://pkg.go.dev/github.com/numaproj/numaflow-go/pkg/sourcer)
 - Implement [User Defined Source Transformers](https://pkg.go.dev/github.com/numaproj/numaflow-go/pkg/sourcetransformer)
-- Implement [User Defined Functions](https://pkg.go.dev/github.com/numaproj/numaflow-go/pkg/function)
-- Implement [User Defined Sinks](https://pkg.go.dev/github.com/numaproj/numaflow-go/pkg/sink)
+- Implement User Defined Functions
+  - [Map](https://pkg.go.dev/github.com/numaproj/numaflow-go/pkg/mapper)
+  - [Reduce](https://pkg.go.dev/github.com/numaproj/numaflow-go/pkg/reducer)
+- Implement [User Defined Sinks](https://pkg.go.dev/github.com/numaproj/numaflow-go/pkg/sinker)
 - Implement [User Defined SideInputs](https://pkg.go.dev/github.com/numaproj/numaflow-go/pkg/sideinput)
\ No newline at end of file
diff --git a/pkg/mapper/options.go b/pkg/mapper/options.go
index d1f3b483..45683be5 100644
--- a/pkg/mapper/options.go
+++ b/pkg/mapper/options.go
@@ -13,7 +13,7 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-func DefaultOptions() *options {
+func defaultOptions() *options {
 	return &options{
 		sockAddr:           address,
 		maxMessageSize:     defaultMaxMessageSize,
diff --git a/pkg/mapper/server.go b/pkg/mapper/server.go
index 5a584df7..60399b24 100644
--- a/pkg/mapper/server.go
+++ b/pkg/mapper/server.go
@@ -20,7 +20,7 @@ type server struct {
 
 // NewServer creates a new map server.
 func NewServer(m Mapper, inputOptions ...Option) numaflow.Server {
-	opts := DefaultOptions()
+	opts := defaultOptions()
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
 	}
diff --git a/pkg/mapstreamer/options.go b/pkg/mapstreamer/options.go
index 5eb1e609..2b5c9290 100644
--- a/pkg/mapstreamer/options.go
+++ b/pkg/mapstreamer/options.go
@@ -13,7 +13,7 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-func DefaultOptions() *options {
+func defaultOptions() *options {
 	return &options{
 		sockAddr:           address,
 		maxMessageSize:     defaultMaxMessageSize,
diff --git a/pkg/mapstreamer/server.go b/pkg/mapstreamer/server.go
index bb8b946c..f080feaf 100644
--- a/pkg/mapstreamer/server.go
+++ b/pkg/mapstreamer/server.go
@@ -19,7 +19,7 @@ type server struct {
 
 // NewServer creates a new map streaming server.
 func NewServer(ms MapStreamer, inputOptions ...Option) numaflow.Server {
-	opts := DefaultOptions()
+	opts := defaultOptions()
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
 	}
diff --git a/pkg/reducer/options.go b/pkg/reducer/options.go
index e0919a9d..e015cdb8 100644
--- a/pkg/reducer/options.go
+++ b/pkg/reducer/options.go
@@ -13,7 +13,7 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-func DefaultOptions() *options {
+func defaultOptions() *options {
 	return &options{
 		sockAddr:           address,
 		maxMessageSize:     defaultMaxMessageSize,
diff --git a/pkg/reducer/server.go b/pkg/reducer/server.go
index 494282e7..53989ebf 100644
--- a/pkg/reducer/server.go
+++ b/pkg/reducer/server.go
@@ -19,7 +19,7 @@ type server struct {
 
 // NewServer creates a new reduce server.
 func NewServer(r ReducerCreator, inputOptions ...Option) numaflow.Server {
-	opts := DefaultOptions()
+	opts := defaultOptions()
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
 	}
diff --git a/pkg/reducestreamer/options.go b/pkg/reducestreamer/options.go
index 7862fb03..3cabe0df 100644
--- a/pkg/reducestreamer/options.go
+++ b/pkg/reducestreamer/options.go
@@ -13,7 +13,7 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-func DefaultOptions() *options {
+func defaultOptions() *options {
 	return &options{
 		sockAddr:           address,
 		maxMessageSize:     defaultMaxMessageSize,
diff --git a/pkg/reducestreamer/server.go b/pkg/reducestreamer/server.go
index 1e180637..b24eda57 100644
--- a/pkg/reducestreamer/server.go
+++ b/pkg/reducestreamer/server.go
@@ -19,7 +19,7 @@ type server struct {
 
 // NewServer creates a new reduceStream server.
 func NewServer(r ReduceStreamerCreator, inputOptions ...Option) numaflow.Server {
-	opts := DefaultOptions()
+	opts := defaultOptions()
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
 	}
diff --git a/pkg/sessionreducer/options.go b/pkg/sessionreducer/options.go
index 6e5da5b7..ba7af1e3 100644
--- a/pkg/sessionreducer/options.go
+++ b/pkg/sessionreducer/options.go
@@ -13,7 +13,7 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-func DefaultOptions() *options {
+func defaultOptions() *options {
 	return &options{
 		sockAddr:           address,
 		maxMessageSize:     defaultMaxMessageSize,
diff --git a/pkg/sessionreducer/server.go b/pkg/sessionreducer/server.go
index 5b630bf3..7bfaf664 100644
--- a/pkg/sessionreducer/server.go
+++ b/pkg/sessionreducer/server.go
@@ -19,7 +19,7 @@ type server struct {
 
 // NewServer creates a new session reduce server.
 func NewServer(r SessionReducerCreator, inputOptions ...Option) numaflow.Server {
-	opts := DefaultOptions()
+	opts := defaultOptions()
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
 	}
diff --git a/pkg/sideinput/options.go b/pkg/sideinput/options.go
index 6703a90f..761ef737 100644
--- a/pkg/sideinput/options.go
+++ b/pkg/sideinput/options.go
@@ -9,8 +9,8 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-// DefaultOptions returns the default options.
-func DefaultOptions() *options {
+// defaultOptions returns the default options.
+func defaultOptions() *options {
 	return &options{
 		sockAddr:       address,
 		maxMessageSize: defaultMaxMessageSize,
diff --git a/pkg/sideinput/server.go b/pkg/sideinput/server.go
index a19a59c9..37cf7d02 100644
--- a/pkg/sideinput/server.go
+++ b/pkg/sideinput/server.go
@@ -20,7 +20,7 @@ type server struct {
 
 // NewSideInputServer creates a new server object.
 func NewSideInputServer(r SideInputRetriever, inputOptions ...Option) numaflow.Server {
-	opts := DefaultOptions()
+	opts := defaultOptions()
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
 	}
diff --git a/pkg/sinker/options.go b/pkg/sinker/options.go
index 2001e930..b9974034 100644
--- a/pkg/sinker/options.go
+++ b/pkg/sinker/options.go
@@ -13,7 +13,7 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-func DefaultOptions() *options {
+func defaultOptions() *options {
 	return &options{
 		sockAddr:           address,
 		maxMessageSize:     defaultMaxMessageSize,
diff --git a/pkg/sinker/server.go b/pkg/sinker/server.go
index adcc7ce3..4833961a 100644
--- a/pkg/sinker/server.go
+++ b/pkg/sinker/server.go
@@ -20,7 +20,7 @@ type sinkServer struct {
 
 // NewServer creates a new sinkServer object.
 func NewServer(h Sinker, inputOptions ...Option) numaflow.Server {
-	opts := DefaultOptions()
+	opts := defaultOptions()
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
 	}
diff --git a/pkg/sourcer/options.go b/pkg/sourcer/options.go
index 43c66af7..a665ee25 100644
--- a/pkg/sourcer/options.go
+++ b/pkg/sourcer/options.go
@@ -13,7 +13,7 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-func DefaultOptions() *options {
+func defaultOptions() *options {
 	return &options{
 		sockAddr:           address,
 		maxMessageSize:     defaultMaxMessageSize,
diff --git a/pkg/sourcer/server.go b/pkg/sourcer/server.go
index b52f5310..58bd01b8 100644
--- a/pkg/sourcer/server.go
+++ b/pkg/sourcer/server.go
@@ -21,7 +21,7 @@ type server struct {
 func NewServer(
 	source Sourcer,
 	inputOptions ...Option) numaflow.Server {
-	var opts = DefaultOptions()
+	var opts = defaultOptions()
 
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
diff --git a/pkg/sourcetransformer/options.go b/pkg/sourcetransformer/options.go
index f98147a5..8cbc2fb4 100644
--- a/pkg/sourcetransformer/options.go
+++ b/pkg/sourcetransformer/options.go
@@ -13,7 +13,7 @@ type options struct {
 // Option is the interface to apply options.
 type Option func(*options)
 
-func DefaultOptions() *options {
+func defaultOptions() *options {
 	return &options{
 		sockAddr:           address,
 		maxMessageSize:     defaultMaxMessageSize,
diff --git a/pkg/sourcetransformer/server.go b/pkg/sourcetransformer/server.go
index 5d6dbeb2..f4bf8775 100644
--- a/pkg/sourcetransformer/server.go
+++ b/pkg/sourcetransformer/server.go
@@ -19,7 +19,7 @@ type server struct {
 
 // NewServer creates a new SourceTransformer server.
 func NewServer(m SourceTransformer, inputOptions ...Option) numaflow.Server {
-	opts := DefaultOptions()
+	opts := defaultOptions()
 	for _, inputOption := range inputOptions {
 		inputOption(opts)
 	}