diff --git a/genai/caching_test.go b/genai/caching_test.go
index 9f2d0f0..27724a1 100644
--- a/genai/caching_test.go
+++ b/genai/caching_test.go
@@ -111,7 +111,7 @@ func testCaching(t *testing.T, client *Client) {
 		argcc := &CachedContent{
 			Model:      model,
 			Expiration: ExpireTimeOrTTL{TTL: ttl},
-			Contents:   []*Content{{Role: "user", Parts: parts}},
+			Contents:   []*Content{NewUserContent(parts...)},
 		}
 		cc := must(client.CreateCachedContent(ctx, argcc))
 		compare(cc, wantExpireTime)
@@ -158,7 +158,7 @@ func testCaching(t *testing.T, client *Client) {
 		txt := strings.Repeat("George Washington was the first president of the United States. ", 3000)
 		argcc := &CachedContent{
 			Model:    model,
-			Contents: []*Content{{Role: "user", Parts: []Part{Text(txt)}}},
+			Contents: []*Content{NewUserContent(Text(txt))},
 		}
 		cc, err := client.CreateCachedContent(ctx, argcc)
 		if err != nil {
diff --git a/genai/chat.go b/genai/chat.go
index f4b95dc..334df1d 100644
--- a/genai/chat.go
+++ b/genai/chat.go
@@ -32,7 +32,7 @@ func (m *GenerativeModel) StartChat() *ChatSession {
 // SendMessage sends a request to the model as part of a chat session.
 func (cs *ChatSession) SendMessage(ctx context.Context, parts ...Part) (*GenerateContentResponse, error) {
 	// Call the underlying client with the entire history plus the argument Content.
-	cs.History = append(cs.History, newUserContent(parts))
+	cs.History = append(cs.History, NewUserContent(parts...))
 	req, err := cs.m.newGenerateContentRequest(cs.History...)
 	if err != nil {
 		return nil, err
@@ -48,7 +48,7 @@ func (cs *ChatSession) SendMessage(ctx context.Context, parts ...Part) (*Generat
 
 // SendMessageStream is like SendMessage, but with a streaming request.
 func (cs *ChatSession) SendMessageStream(ctx context.Context, parts ...Part) *GenerateContentResponseIterator {
-	cs.History = append(cs.History, newUserContent(parts))
+	cs.History = append(cs.History, NewUserContent(parts...))
 	req, err := cs.m.newGenerateContentRequest(cs.History...)
 	if err != nil {
 		return &GenerateContentResponseIterator{err: err}
diff --git a/genai/client.go b/genai/client.go
index 1d13112..7e81777 100644
--- a/genai/client.go
+++ b/genai/client.go
@@ -179,7 +179,7 @@ func fullModelName(name string) string {
 
 // GenerateContent produces a single request and response.
 func (m *GenerativeModel) GenerateContent(ctx context.Context, parts ...Part) (*GenerateContentResponse, error) {
-	content := newUserContent(parts)
+	content := NewUserContent(parts...)
 	req, err := m.newGenerateContentRequest(content)
 	if err != nil {
 		return nil, err
@@ -194,7 +194,7 @@ func (m *GenerativeModel) GenerateContent(ctx context.Context, parts ...Part) (*
 // GenerateContentStream returns an iterator that enumerates responses.
 func (m *GenerativeModel) GenerateContentStream(ctx context.Context, parts ...Part) *GenerateContentResponseIterator {
 	iter := &GenerateContentResponseIterator{}
-	req, err := m.newGenerateContentRequest(newUserContent(parts))
+	req, err := m.newGenerateContentRequest(NewUserContent(parts...))
 	if err != nil {
 		iter.err = err
 	} else {
@@ -241,10 +241,6 @@ func (m *GenerativeModel) newGenerateContentRequest(contents ...*Content) (*pb.G
 	})
 }
 
-func newUserContent(parts []Part) *Content {
-	return &Content{Role: roleUser, Parts: parts}
-}
-
 // GenerateContentResponseIterator is an iterator over GnerateContentResponse.
 type GenerateContentResponseIterator struct {
 	sc     pb.GenerativeService_StreamGenerateContentClient
@@ -313,7 +309,7 @@ func (iter *GenerateContentResponseIterator) MergedResponse() *GenerateContentRe
 
 // CountTokens counts the number of tokens in the content.
 func (m *GenerativeModel) CountTokens(ctx context.Context, parts ...Part) (*CountTokensResponse, error) {
-	req, err := m.newCountTokensRequest(newUserContent(parts))
+	req, err := m.newCountTokensRequest(NewUserContent(parts...))
 	if err != nil {
 		return nil, err
 	}
diff --git a/genai/client_test.go b/genai/client_test.go
index a129e6f..16eb929 100644
--- a/genai/client_test.go
+++ b/genai/client_test.go
@@ -814,7 +814,7 @@ func TestRecoverPanic(t *testing.T) {
 		Response: map[string]any{"x": 1 + 2i}, // complex values are invalid
 	}
 	var m GenerativeModel
-	_, err := m.newGenerateContentRequest(newUserContent([]Part{fr}))
+	_, err := m.newGenerateContentRequest(NewUserContent(fr))
 	if err == nil {
 		t.Fatal("got nil, want error")
 	}
diff --git a/genai/content.go b/genai/content.go
index 59769d3..030d1ce 100644
--- a/genai/content.go
+++ b/genai/content.go
@@ -170,3 +170,13 @@ func (c *Candidate) FunctionCalls() []FunctionCall {
 	}
 	return fcs
 }
+
+// NewUserContent returns a *Content with a "user" role set and one or more
+// parts.
+func NewUserContent(parts ...Part) *Content {
+	content := &Content{Role: roleUser, Parts: []Part{}}
+	for _, part := range parts {
+		content.Parts = append(content.Parts, part)
+	}
+	return content
+}
diff --git a/genai/embed.go b/genai/embed.go
index 95dbd45..cea90ec 100644
--- a/genai/embed.go
+++ b/genai/embed.go
@@ -65,7 +65,7 @@ func (m *EmbeddingModel) EmbedContentWithTitle(ctx context.Context, title string
 func newEmbedContentRequest(model string, tt TaskType, title string, parts []Part) *pb.EmbedContentRequest {
 	req := &pb.EmbedContentRequest{
 		Model:   model,
-		Content: newUserContent(parts).toProto(),
+		Content: NewUserContent(parts...).toProto(),
 	}
 	// A non-empty title overrides the task type.
 	if title != "" {
diff --git a/genai/example_test.go b/genai/example_test.go
index b325e59..c740882 100644
--- a/genai/example_test.go
+++ b/genai/example_test.go
@@ -191,9 +191,7 @@ func ExampleGenerativeModel_GenerateContent_config() {
 	model.SetTopP(0.5)
 	model.SetTopK(20)
 	model.SetMaxOutputTokens(100)
-	model.SystemInstruction = &genai.Content{
-		Parts: []genai.Part{genai.Text("You are Yoda from Star Wars.")},
-	}
+	model.SystemInstruction = genai.NewUserContent(genai.Text("You are Yoda from Star Wars."))
 	model.ResponseMIMEType = "application/json"
 	resp, err := model.GenerateContent(ctx, genai.Text("What is the average size of a swallow?"))
 	if err != nil {
@@ -212,9 +210,7 @@ func ExampleGenerativeModel_GenerateContent_systemInstruction() {
 	defer client.Close()
 
 	model := client.GenerativeModel("gemini-1.5-flash")
-	model.SystemInstruction = &genai.Content{
-		Parts: []genai.Part{genai.Text("You are a cat. Your name is Neko.")},
-	}
+	model.SystemInstruction = genai.NewUserContent(genai.Text("You are a cat. Your name is Neko."))
 	resp, err := model.GenerateContent(ctx, genai.Text("Good morning! How are you?"))
 	if err != nil {
 		log.Fatal(err)
@@ -482,7 +478,7 @@ func ExampleGenerativeModel_CountTokens_cachedContent() {
 	txt := strings.Repeat("George Washington was the first president of the United States. ", 3000)
 	argcc := &genai.CachedContent{
 		Model:    "gemini-1.5-flash-001",
-		Contents: []*genai.Content{{Role: "user", Parts: []genai.Part{genai.Text(txt)}}},
+		Contents: []*genai.Content{genai.NewUserContent(genai.Text(txt))},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -692,9 +688,7 @@ func ExampleGenerativeModel_CountTokens_systemInstruction() {
 	// ( total_tokens: 10 )
 
 	// Same prompt, this time with system instruction
-	model.SystemInstruction = &genai.Content{
-		Parts: []genai.Part{genai.Text("You are a cat. Your name is Neko.")},
-	}
+	model.SystemInstruction = genai.NewUserContent(genai.Text("You are a cat. Your name is Neko."))
 	respWithInstruction, err := model.CountTokens(ctx, genai.Text(prompt))
 	if err != nil {
 		log.Fatal(err)
@@ -1236,8 +1230,8 @@ func ExampleCachedContent_create() {
 
 	argcc := &genai.CachedContent{
 		Model:             "gemini-1.5-flash-001",
-		SystemInstruction: userContent(genai.Text("You are an expert analyzing transcripts.")),
-		Contents:          []*genai.Content{userContent(fd)},
+		SystemInstruction: genai.NewUserContent(genai.Text("You are an expert analyzing transcripts.")),
+		Contents:          []*genai.Content{genai.NewUserContent(fd)},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -1273,7 +1267,7 @@ func ExampleCachedContent_createFromChat() {
 
 	modelName := "gemini-1.5-flash-001"
 	model := client.GenerativeModel(modelName)
-	model.SystemInstruction = userContent(genai.Text("You are an expert analyzing transcripts."))
+	model.SystemInstruction = genai.NewUserContent(genai.Text("You are an expert analyzing transcripts."))
 
 	cs := model.StartChat()
 	resp, err := cs.SendMessage(ctx, genai.Text("Hi, could you summarize this transcript?"), fd)
@@ -1327,8 +1321,8 @@ func ExampleClient_GetCachedContent() {
 
 	argcc := &genai.CachedContent{
 		Model:             "gemini-1.5-flash-001",
-		SystemInstruction: userContent(genai.Text("You are an expert analyzing transcripts.")),
-		Contents:          []*genai.Content{userContent(fd)},
+		SystemInstruction: genai.NewUserContent(genai.Text("You are an expert analyzing transcripts.")),
+		Contents:          []*genai.Content{genai.NewUserContent(fd)},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -1372,8 +1366,8 @@ func ExampleClient_ListCachedContents() {
 
 	argcc := &genai.CachedContent{
 		Model:             "gemini-1.5-flash-001",
-		SystemInstruction: userContent(genai.Text("You are an expert analyzing transcripts.")),
-		Contents:          []*genai.Content{userContent(fd)},
+		SystemInstruction: genai.NewUserContent(genai.Text("You are an expert analyzing transcripts.")),
+		Contents:          []*genai.Content{genai.NewUserContent(fd)},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -1413,8 +1407,8 @@ func ExampleClient_UpdateCachedContent() {
 
 	argcc := &genai.CachedContent{
 		Model:             "gemini-1.5-flash-001",
-		SystemInstruction: userContent(genai.Text("You are an expert analyzing transcripts.")),
-		Contents:          []*genai.Content{userContent(fd)},
+		SystemInstruction: genai.NewUserContent(genai.Text("You are an expert analyzing transcripts.")),
+		Contents:          []*genai.Content{genai.NewUserContent(fd)},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -1490,19 +1484,6 @@ func ExampleClient_setProxy() {
 	printResponse(resp)
 }
 
-// userContent helps create a *genai.Content with a "user" role and one or
-// more parts with less verbosity.
-func userContent(parts ...genai.Part) *genai.Content {
-	content := &genai.Content{
-		Role:  "user",
-		Parts: []genai.Part{},
-	}
-	for _, part := range parts {
-		content.Parts = append(content.Parts, part)
-	}
-	return content
-}
-
 func printResponse(resp *genai.GenerateContentResponse) {
 	for _, cand := range resp.Candidates {
 		if cand.Content != nil {
diff --git a/genai/internal/samples/docs-snippets_test.go b/genai/internal/samples/docs-snippets_test.go
index ccd6255..c91df8b 100644
--- a/genai/internal/samples/docs-snippets_test.go
+++ b/genai/internal/samples/docs-snippets_test.go
@@ -196,9 +196,7 @@ func ExampleGenerativeModel_GenerateContent_config() {
 	model.SetTopP(0.5)
 	model.SetTopK(20)
 	model.SetMaxOutputTokens(100)
-	model.SystemInstruction = &genai.Content{
-		Parts: []genai.Part{genai.Text("You are Yoda from Star Wars.")},
-	}
+	model.SystemInstruction = genai.NewUserContent(genai.Text("You are Yoda from Star Wars."))
 	model.ResponseMIMEType = "application/json"
 	resp, err := model.GenerateContent(ctx, genai.Text("What is the average size of a swallow?"))
 	if err != nil {
@@ -218,9 +216,7 @@ func ExampleGenerativeModel_GenerateContent_systemInstruction() {
 
 	// [START system_instruction]
 	model := client.GenerativeModel("gemini-1.5-flash")
-	model.SystemInstruction = &genai.Content{
-		Parts: []genai.Part{genai.Text("You are a cat. Your name is Neko.")},
-	}
+	model.SystemInstruction = genai.NewUserContent(genai.Text("You are a cat. Your name is Neko."))
 	resp, err := model.GenerateContent(ctx, genai.Text("Good morning! How are you?"))
 	if err != nil {
 		log.Fatal(err)
@@ -498,7 +494,7 @@ func ExampleGenerativeModel_CountTokens_cachedContent() {
 	txt := strings.Repeat("George Washington was the first president of the United States. ", 3000)
 	argcc := &genai.CachedContent{
 		Model:    "gemini-1.5-flash-001",
-		Contents: []*genai.Content{{Role: "user", Parts: []genai.Part{genai.Text(txt)}}},
+		Contents: []*genai.Content{genai.NewUserContent(genai.Text(txt))},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -714,9 +710,7 @@ func ExampleGenerativeModel_CountTokens_systemInstruction() {
 	// ( total_tokens: 10 )
 
 	// Same prompt, this time with system instruction
-	model.SystemInstruction = &genai.Content{
-		Parts: []genai.Part{genai.Text("You are a cat. Your name is Neko.")},
-	}
+	model.SystemInstruction = genai.NewUserContent(genai.Text("You are a cat. Your name is Neko."))
 	respWithInstruction, err := model.CountTokens(ctx, genai.Text(prompt))
 	if err != nil {
 		log.Fatal(err)
@@ -1275,8 +1269,8 @@ func ExampleCachedContent_create() {
 
 	argcc := &genai.CachedContent{
 		Model:             "gemini-1.5-flash-001",
-		SystemInstruction: userContent(genai.Text("You are an expert analyzing transcripts.")),
-		Contents:          []*genai.Content{userContent(fd)},
+		SystemInstruction: genai.NewUserContent(genai.Text("You are an expert analyzing transcripts.")),
+		Contents:          []*genai.Content{genai.NewUserContent(fd)},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -1313,7 +1307,7 @@ func ExampleCachedContent_createFromChat() {
 
 	modelName := "gemini-1.5-flash-001"
 	model := client.GenerativeModel(modelName)
-	model.SystemInstruction = userContent(genai.Text("You are an expert analyzing transcripts."))
+	model.SystemInstruction = genai.NewUserContent(genai.Text("You are an expert analyzing transcripts."))
 
 	cs := model.StartChat()
 	resp, err := cs.SendMessage(ctx, genai.Text("Hi, could you summarize this transcript?"), fd)
@@ -1370,8 +1364,8 @@ func ExampleClient_GetCachedContent() {
 
 	argcc := &genai.CachedContent{
 		Model:             "gemini-1.5-flash-001",
-		SystemInstruction: userContent(genai.Text("You are an expert analyzing transcripts.")),
-		Contents:          []*genai.Content{userContent(fd)},
+		SystemInstruction: genai.NewUserContent(genai.Text("You are an expert analyzing transcripts.")),
+		Contents:          []*genai.Content{genai.NewUserContent(fd)},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -1417,8 +1411,8 @@ func ExampleClient_ListCachedContents() {
 
 	argcc := &genai.CachedContent{
 		Model:             "gemini-1.5-flash-001",
-		SystemInstruction: userContent(genai.Text("You are an expert analyzing transcripts.")),
-		Contents:          []*genai.Content{userContent(fd)},
+		SystemInstruction: genai.NewUserContent(genai.Text("You are an expert analyzing transcripts.")),
+		Contents:          []*genai.Content{genai.NewUserContent(fd)},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -1459,8 +1453,8 @@ func ExampleClient_UpdateCachedContent() {
 
 	argcc := &genai.CachedContent{
 		Model:             "gemini-1.5-flash-001",
-		SystemInstruction: userContent(genai.Text("You are an expert analyzing transcripts.")),
-		Contents:          []*genai.Content{userContent(fd)},
+		SystemInstruction: genai.NewUserContent(genai.Text("You are an expert analyzing transcripts.")),
+		Contents:          []*genai.Content{genai.NewUserContent(fd)},
 	}
 	cc, err := client.CreateCachedContent(ctx, argcc)
 	if err != nil {
@@ -1536,19 +1530,6 @@ func ExampleClient_setProxy() {
 	printResponse(resp)
 }
 
-// userContent helps create a *genai.Content with a "user" role and one or
-// more parts with less verbosity.
-func userContent(parts ...genai.Part) *genai.Content {
-	content := &genai.Content{
-		Role:  "user",
-		Parts: []genai.Part{},
-	}
-	for _, part := range parts {
-		content.Parts = append(content.Parts, part)
-	}
-	return content
-}
-
 func printResponse(resp *genai.GenerateContentResponse) {
 	for _, cand := range resp.Candidates {
 		if cand.Content != nil {