simplify renderer and parser, add tests

model/parsers/nemotron3nano.go

@@ -12,6 +12,7 @@ type Nemotron3NanoParserState int
 
 const (
 	Nemotron3NanoCollectingThinking Nemotron3NanoParserState = iota
+	Nemotron3NanoSkipWhitespaceAfterThinking
 	Nemotron3NanoCollectingContent
 	Nemotron3NanoCollectingToolCalls
 )
@@ -23,19 +24,14 @@ const (
 )
 
 type Nemotron3NanoParser struct {
-	state              Nemotron3NanoParserState
-	buffer             strings.Builder
-	tools              []api.Tool
-	hasThinkingSupport bool
+	state       Nemotron3NanoParserState
+	buffer      strings.Builder
+	tools       []api.Tool
+	HasThinking bool
 }
 
-func (p *Nemotron3NanoParser) HasToolSupport() bool {
-	return true
-}
-
-func (p *Nemotron3NanoParser) HasThinkingSupport() bool {
-	return p.hasThinkingSupport
-}
+func (p *Nemotron3NanoParser) HasToolSupport() bool     { return true }
+func (p *Nemotron3NanoParser) HasThinkingSupport() bool { return p.HasThinking }
 
 func (p *Nemotron3NanoParser) Init(tools []api.Tool, lastMessage *api.Message, thinkValue *api.ThinkValue) []api.Tool {
 	p.tools = tools
@@ -115,133 +111,103 @@ func (p *Nemotron3NanoParser) parseEvents() []nemotronEvent {
 	return all
 }
 
+// emitWithPartialCheck extracts unambiguous content before a potential partial tag
+func (p *Nemotron3NanoParser) emitWithPartialCheck(bufStr, tag string) (unambiguous, ambiguous string) {
+	if overlapLen := overlap(bufStr, tag); overlapLen > 0 {
+		beforePartialTag := bufStr[:len(bufStr)-overlapLen]
+		trailingLen := trailingWhitespaceLen(beforePartialTag)
+		return bufStr[:len(beforePartialTag)-trailingLen], bufStr[len(beforePartialTag)-trailingLen:]
+	}
+	wsLen := trailingWhitespaceLen(bufStr)
+	return bufStr[:len(bufStr)-wsLen], bufStr[len(bufStr)-wsLen:]
+}
+
 func (p *Nemotron3NanoParser) eat() ([]nemotronEvent, bool) {
-	var events []nemotronEvent
 	bufStr := p.buffer.String()
 	if bufStr == "" {
-		return events, false
+		return nil, false
 	}
 
 	switch p.state {
 	case Nemotron3NanoCollectingThinking:
 		if strings.Contains(bufStr, nemotronThinkClose) {
 			split := strings.SplitN(bufStr, nemotronThinkClose, 2)
-			thinking := split[0]
-			thinking = strings.TrimRightFunc(thinking, unicode.IsSpace)
-
-			remaining := split[1]
-			remaining = strings.TrimLeftFunc(remaining, unicode.IsSpace)
-
+			thinking := strings.TrimRightFunc(split[0], unicode.IsSpace)
 			p.buffer.Reset()
-			p.buffer.WriteString(remaining)
-			p.state = Nemotron3NanoCollectingContent
-
-			if len(thinking) > 0 {
-				events = append(events, nemotronEventThinkingContent{content: thinking})
+			remainder := strings.TrimLeftFunc(split[1], unicode.IsSpace)
+			p.buffer.WriteString(remainder)
+			// Transition to whitespace-skipping state if buffer is empty,
+			// otherwise go directly to content collection
+			if remainder == "" {
+				p.state = Nemotron3NanoSkipWhitespaceAfterThinking
+			} else {
+				p.state = Nemotron3NanoCollectingContent
 			}
-			return events, true
-		} else if overlapLen := overlap(bufStr, nemotronThinkClose); overlapLen > 0 {
-			beforePartialTag := bufStr[:len(bufStr)-overlapLen]
-			trailingLen := trailingWhitespaceLen(beforePartialTag)
-			ambiguousStart := len(beforePartialTag) - trailingLen
-
-			unambiguous := bufStr[:ambiguousStart]
-			ambiguous := bufStr[ambiguousStart:]
-			p.buffer.Reset()
-			p.buffer.WriteString(ambiguous)
-			if len(unambiguous) > 0 {
-				events = append(events, nemotronEventThinkingContent{content: unambiguous})
+			if thinking != "" {
+				return []nemotronEvent{nemotronEventThinkingContent{content: thinking}}, true
 			}
-			return events, false
-		} else {
-			whitespaceLen := trailingWhitespaceLen(bufStr)
-			ambiguousStart := len(bufStr) - whitespaceLen
-
-			unambiguous := bufStr[:ambiguousStart]
-			ambiguous := bufStr[ambiguousStart:]
-			p.buffer.Reset()
-			p.buffer.WriteString(ambiguous)
-			if len(unambiguous) > 0 {
-				events = append(events, nemotronEventThinkingContent{content: unambiguous})
-			}
-			return events, false
+			return nil, true
 		}
+		unambig, ambig := p.emitWithPartialCheck(bufStr, nemotronThinkClose)
+		p.buffer.Reset()
+		p.buffer.WriteString(ambig)
+		if unambig != "" {
+			return []nemotronEvent{nemotronEventThinkingContent{content: unambig}}, false
+		}
+		return nil, false
+
+	// We only want to skip whitespace between thinking and content
+	case Nemotron3NanoSkipWhitespaceAfterThinking:
+		bufStr = strings.TrimLeftFunc(bufStr, unicode.IsSpace)
+		p.buffer.Reset()
+		p.buffer.WriteString(bufStr)
+		if bufStr == "" {
+			return nil, false
+		}
+		p.state = Nemotron3NanoCollectingContent
+		return nil, true
 
 	case Nemotron3NanoCollectingContent:
-		switch {
-		case strings.Contains(bufStr, nemotronToolCallOpen):
+		if strings.Contains(bufStr, nemotronToolCallOpen) {
 			split := strings.SplitN(bufStr, nemotronToolCallOpen, 2)
-			contentBefore := strings.TrimRightFunc(split[0], unicode.IsSpace)
-			remaining := split[1]
-
+			content := strings.TrimRightFunc(split[0], unicode.IsSpace)
 			p.buffer.Reset()
-			p.buffer.WriteString(remaining)
+			p.buffer.WriteString(split[1])
 			p.state = Nemotron3NanoCollectingToolCalls
-
-			if len(contentBefore) > 0 {
-				events = append(events, nemotronEventContent{content: contentBefore})
+			if content != "" {
+				return []nemotronEvent{nemotronEventContent{content: content}}, true
 			}
-			return events, true
-		default:
-			// Check for partial tool call tag
-			if overlapLen := overlap(bufStr, nemotronToolCallOpen); overlapLen > 0 {
-				beforePartialTag := bufStr[:len(bufStr)-overlapLen]
-				trailingLen := trailingWhitespaceLen(beforePartialTag)
-				ambiguousStart := len(beforePartialTag) - trailingLen
-
-				unambiguous := bufStr[:ambiguousStart]
-				ambiguous := bufStr[ambiguousStart:]
-				p.buffer.Reset()
-				p.buffer.WriteString(ambiguous)
-				if len(unambiguous) > 0 {
-					events = append(events, nemotronEventContent{content: unambiguous})
-				}
-				return events, false
-			}
-
-			// Otherwise emit content, withholding trailing whitespace
-			whitespaceLen := trailingWhitespaceLen(bufStr)
-			ambiguousStart := len(bufStr) - whitespaceLen
-
-			unambiguous := bufStr[:ambiguousStart]
-			ambiguous := bufStr[ambiguousStart:]
-			p.buffer.Reset()
-			p.buffer.WriteString(ambiguous)
-			if len(unambiguous) > 0 {
-				events = append(events, nemotronEventContent{content: unambiguous})
-			}
-			return events, false
+			return nil, true
 		}
+		unambig, ambig := p.emitWithPartialCheck(bufStr, nemotronToolCallOpen)
+		p.buffer.Reset()
+		p.buffer.WriteString(ambig)
+		if unambig != "" {
+			return []nemotronEvent{nemotronEventContent{content: unambig}}, false
+		}
+		return nil, false
 
 	case Nemotron3NanoCollectingToolCalls:
-		// Look for complete tool call: <function=name>...</function>
 		if strings.Contains(bufStr, nemotronToolCallClose) {
-			// We have a complete tool call block
 			split := strings.SplitN(bufStr, nemotronToolCallClose, 2)
-			toolContent := split[0]
 			remaining := strings.TrimLeftFunc(split[1], unicode.IsSpace)
-
-			// Parse the tool call
-			if toolCall, err := p.parseToolCall(toolContent); err == nil {
-				events = append(events, nemotronEventToolCall{toolCall: toolCall})
-			}
-
 			p.buffer.Reset()
 			p.buffer.WriteString(remaining)
 
-			// Check if there are more tool calls
-			if strings.Contains(remaining, nemotronToolCallOpen) {
-				// Stay in tool call state
-				return events, true
+			var events []nemotronEvent
+			if tc, err := p.parseToolCall(split[0]); err == nil {
+				events = append(events, nemotronEventToolCall{toolCall: tc})
 			}
 
-			p.state = Nemotron3NanoCollectingContent
+			if !strings.Contains(remaining, nemotronToolCallOpen) {
+				p.state = Nemotron3NanoCollectingContent
+			}
 			return events, true
 		}
-		return events, false
+		return nil, false
 	}
 
-	return events, false
+	return nil, false
 }
 
 var (

model/parsers/nemotron3nano_test.go

@@ -0,0 +1,486 @@
+package parsers
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+
+	"github.com/ollama/ollama/api"
+)
+
+func TestNemotron3NanoParser(t *testing.T) {
+	tests := []struct {
+		name             string
+		input            string
+		thinkValue       *api.ThinkValue
+		expectedContent  string
+		expectedThinking string
+		expectedCalls    []api.ToolCall
+	}{
+		{
+			name:            "simple content - no thinking",
+			input:           "Hello, how can I help you?",
+			thinkValue:      nil,
+			expectedContent: "Hello, how can I help you?",
+		},
+		{
+			name:            "simple content - thinking disabled",
+			input:           "Hello, how can I help you?",
+			thinkValue:      &api.ThinkValue{Value: false},
+			expectedContent: "Hello, how can I help you?",
+		},
+		{
+			name:             "thinking then content",
+			input:            "Let me think about this...</think>\nHere is my answer.",
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "Let me think about this...",
+			expectedContent:  "Here is my answer.",
+		},
+		{
+			name:             "thinking with newlines",
+			input:            "Step 1: Analyze\nStep 2: Process\nStep 3: Conclude</think>\nThe answer is 42.",
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "Step 1: Analyze\nStep 2: Process\nStep 3: Conclude",
+			expectedContent:  "The answer is 42.",
+		},
+		{
+			name:       "simple tool call",
+			input:      "<tool_call>\n<function=get_weather>\n<parameter=city>\nParis\n</parameter>\n</function>\n</tool_call>",
+			thinkValue: nil,
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "Paris"},
+					},
+				},
+			},
+		},
+		{
+			name:            "content then tool call",
+			input:           "Let me check the weather.\n<tool_call>\n<function=get_weather>\n<parameter=city>\nNYC\n</parameter>\n</function>\n</tool_call>",
+			thinkValue:      nil,
+			expectedContent: "Let me check the weather.",
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "NYC"},
+					},
+				},
+			},
+		},
+		{
+			name:       "tool call with multiple parameters",
+			input:      "<tool_call>\n<function=book_flight>\n<parameter=from>\nSFO\n</parameter>\n<parameter=to>\nNYC\n</parameter>\n</function>\n</tool_call>",
+			thinkValue: nil,
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name: "book_flight",
+						Arguments: map[string]any{
+							"from": "SFO",
+							"to":   "NYC",
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "multiple tool calls",
+			input: "<tool_call>\n<function=get_weather>\n<parameter=city>\nSan Francisco\n</parameter>\n</function>\n</tool_call>\n" +
+				"<tool_call>\n<function=get_weather>\n<parameter=city>\nNew York\n</parameter>\n</function>\n</tool_call>",
+			thinkValue: nil,
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "San Francisco"},
+					},
+				},
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "New York"},
+					},
+				},
+			},
+		},
+		{
+			name:             "thinking then tool call",
+			input:            "I should check the weather...</think>\n<tool_call>\n<function=get_weather>\n<parameter=city>\nParis\n</parameter>\n</function>\n</tool_call>",
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "I should check the weather...",
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "Paris"},
+					},
+				},
+			},
+		},
+		{
+			name:             "thinking content then tool call",
+			input:            "Let me think...</think>\nI'll check for you.\n<tool_call>\n<function=search>\n<parameter=query>\ntest\n</parameter>\n</function>\n</tool_call>",
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "Let me think...",
+			expectedContent:  "I'll check for you.",
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "search",
+						Arguments: map[string]any{"query": "test"},
+					},
+				},
+			},
+		},
+		{
+			name:       "tool call with multiline parameter value",
+			input:      "<tool_call>\n<function=create_note>\n<parameter=content>\nLine 1\nLine 2\nLine 3\n</parameter>\n</function>\n</tool_call>",
+			thinkValue: nil,
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "create_note",
+						Arguments: map[string]any{"content": "Line 1\nLine 2\nLine 3"},
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			p := &Nemotron3NanoParser{HasThinking: tt.thinkValue != nil && tt.thinkValue.Bool()}
+			p.Init(nil, nil, tt.thinkValue)
+
+			content, thinking, calls, err := p.Add(tt.input, false)
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+
+			// Drain remaining content
+			finalContent, finalThinking, finalCalls, err := p.Add("", true)
+			if err != nil {
+				t.Fatalf("unexpected error on done: %v", err)
+			}
+			content += finalContent
+			thinking += finalThinking
+			calls = append(calls, finalCalls...)
+
+			if diff := cmp.Diff(content, tt.expectedContent); diff != "" {
+				t.Errorf("content mismatch (-got +want):\n%s", diff)
+			}
+			if diff := cmp.Diff(thinking, tt.expectedThinking); diff != "" {
+				t.Errorf("thinking mismatch (-got +want):\n%s", diff)
+			}
+			if diff := cmp.Diff(calls, tt.expectedCalls); diff != "" {
+				t.Errorf("calls mismatch (-got +want):\n%s", diff)
+			}
+		})
+	}
+}
+
+func TestNemotron3NanoParser_Streaming(t *testing.T) {
+	tests := []struct {
+		name             string
+		chunks           []string
+		thinkValue       *api.ThinkValue
+		expectedContent  string
+		expectedThinking string
+		expectedCalls    []api.ToolCall
+	}{
+		{
+			name:            "streaming content character by character",
+			chunks:          []string{"H", "e", "l", "l", "o", ",", " ", "w", "o", "r", "l", "d", "!"},
+			thinkValue:      nil,
+			expectedContent: "Hello, world!",
+		},
+		{
+			name:            "streaming content small tokens",
+			chunks:          []string{"Hel", "lo", ", ", "how ", "can", " I", " help", " you", " today", "?"},
+			thinkValue:      nil,
+			expectedContent: "Hello, how can I help you today?",
+		},
+		{
+			name:             "streaming thinking then content - granular",
+			chunks:           []string{"Let", " me", " th", "ink", " about", " this", "...", "<", "/", "think", ">", "\n", "Here", " is", " my", " answer", "."},
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "Let me think about this...",
+			expectedContent:  "Here is my answer.",
+		},
+		{
+			name:             "streaming thinking with newlines - granular",
+			chunks:           []string{"Step", " 1", ":", " Ana", "lyze\n", "Step", " 2", ":", " Pro", "cess", "</", "thi", "nk>", "\n", "The", " ans", "wer."},
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "Step 1: Analyze\nStep 2: Process",
+			expectedContent:  "The answer.",
+		},
+		{
+			name:       "streaming tool call - highly granular",
+			chunks:     []string{"<", "tool", "_", "call", ">", "\n", "<", "func", "tion", "=", "get", "_", "weather", ">", "\n", "<", "param", "eter", "=", "city", ">", "\n", "Par", "is", "\n", "</", "param", "eter", ">", "\n", "</", "func", "tion", ">", "\n", "</", "tool", "_", "call", ">"},
+			thinkValue: nil,
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "Paris"},
+					},
+				},
+			},
+		},
+		{
+			name:            "streaming content then tool call - granular",
+			chunks:          []string{"Let", " me", " check", " the", " weather", ".", "\n<", "tool_call", ">", "\n", "<function=", "get_weather", ">", "\n", "<parameter=", "city", ">", "\n", "NYC", "\n", "</parameter>", "\n", "</function>", "\n", "</tool_call>"},
+			thinkValue:      nil,
+			expectedContent: "Let me check the weather.",
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "NYC"},
+					},
+				},
+			},
+		},
+		{
+			name:   "tool call tag split character by character",
+			chunks: []string{"<", "t", "o", "o", "l", "_", "c", "a", "l", "l", ">", "\n", "<", "f", "u", "n", "c", "t", "i", "o", "n", "=", "t", "e", "s", "t", ">", "\n", "<", "/", "f", "u", "n", "c", "t", "i", "o", "n", ">", "\n", "<", "/", "t", "o", "o", "l", "_", "c", "a", "l", "l", ">"},
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "test",
+						Arguments: map[string]any{},
+					},
+				},
+			},
+		},
+		{
+			name:             "thinking close tag split character by character",
+			chunks:           []string{"I", "'", "m", " ", "t", "h", "i", "n", "k", "i", "n", "g", ".", ".", ".", "<", "/", "t", "h", "i", "n", "k", ">", "\n", "D", "o", "n", "e", "!"},
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "I'm thinking...",
+			expectedContent:  "Done!",
+		},
+		{
+			name:             "multiple whitespace after think tag - separate chunks",
+			chunks:           []string{"Thinking...", "</think>", "\n", "\n", " ", "Content here."},
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "Thinking...",
+			expectedContent:  "Content here.",
+		},
+		{
+			name:       "tool call with multiple parameters - streaming",
+			chunks:     []string{"<tool_", "call>\n", "<function", "=book_", "flight>", "\n<para", "meter=", "from>\n", "SFO\n", "</param", "eter>", "\n<param", "eter=to", ">\nNYC", "\n</para", "meter>", "\n</func", "tion>\n", "</tool_", "call>"},
+			thinkValue: nil,
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name: "book_flight",
+						Arguments: map[string]any{
+							"from": "SFO",
+							"to":   "NYC",
+						},
+					},
+				},
+			},
+		},
+		{
+			name:             "thinking then content then tool call - streaming",
+			chunks:           []string{"Ana", "lyzing", " your", " request", "...", "</", "think", ">\n", "I'll", " check", " that", " for", " you", ".", "\n", "<tool", "_call", ">\n", "<function", "=search", ">\n", "<parameter", "=query", ">\n", "test", " query", "\n</", "parameter", ">\n", "</function", ">\n", "</tool", "_call", ">"},
+			thinkValue:       &api.ThinkValue{Value: true},
+			expectedThinking: "Analyzing your request...",
+			expectedContent:  "I'll check that for you.",
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "search",
+						Arguments: map[string]any{"query": "test query"},
+					},
+				},
+			},
+		},
+		{
+			name: "multiple tool calls - streaming",
+			chunks: []string{
+				"<tool_call>", "\n", "<function=", "get_weather>", "\n",
+				"<parameter=", "city>\n", "San Fran", "cisco\n", "</parameter>", "\n",
+				"</function>", "\n", "</tool_call>", "\n",
+				"<tool_", "call>\n", "<function", "=get_weather", ">\n",
+				"<param", "eter=city", ">\nNew", " York\n", "</parameter>\n",
+				"</function>\n", "</tool_call>",
+			},
+			thinkValue: nil,
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "San Francisco"},
+					},
+				},
+				{
+					Function: api.ToolCallFunction{
+						Name:      "get_weather",
+						Arguments: map[string]any{"city": "New York"},
+					},
+				},
+			},
+		},
+		{
+			name:       "tool call with multiline parameter - streaming",
+			chunks:     []string{"<tool_call>\n", "<function=", "create_note>\n", "<parameter=", "content>\n", "Line 1", "\nLine", " 2\n", "Line 3", "\n</parameter>\n", "</function>\n", "</tool_call>"},
+			thinkValue: nil,
+			expectedCalls: []api.ToolCall{
+				{
+					Function: api.ToolCallFunction{
+						Name:      "create_note",
+						Arguments: map[string]any{"content": "Line 1\nLine 2\nLine 3"},
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			p := &Nemotron3NanoParser{HasThinking: tt.thinkValue != nil && tt.thinkValue.Bool()}
+			p.Init(nil, nil, tt.thinkValue)
+
+			var allContent string
+			var allThinking string
+			var allCalls []api.ToolCall
+
+			for _, chunk := range tt.chunks {
+				content, thinking, calls, err := p.Add(chunk, false)
+				if err != nil {
+					t.Fatalf("unexpected error: %v", err)
+				}
+				allContent += content
+				allThinking += thinking
+				allCalls = append(allCalls, calls...)
+			}
+
+			// Drain
+			content, thinking, calls, err := p.Add("", true)
+			if err != nil {
+				t.Fatalf("unexpected error on done: %v", err)
+			}
+			allContent += content
+			allThinking += thinking
+			allCalls = append(allCalls, calls...)
+
+			if diff := cmp.Diff(allContent, tt.expectedContent); diff != "" {
+				t.Errorf("content mismatch (-got +want):\n%s", diff)
+			}
+			if diff := cmp.Diff(allThinking, tt.expectedThinking); diff != "" {
+				t.Errorf("thinking mismatch (-got +want):\n%s", diff)
+			}
+			if diff := cmp.Diff(allCalls, tt.expectedCalls); diff != "" {
+				t.Errorf("calls mismatch (-got +want):\n%s", diff)
+			}
+		})
+	}
+}
+
+func TestNemotron3NanoParser_HasToolSupport(t *testing.T) {
+	p := &Nemotron3NanoParser{}
+	if !p.HasToolSupport() {
+		t.Error("expected HasToolSupport to return true")
+	}
+}
+
+func TestNemotron3NanoParser_HasThinkingSupport(t *testing.T) {
+	t.Run("with thinking enabled", func(t *testing.T) {
+		p := &Nemotron3NanoParser{HasThinking: true}
+		if !p.HasThinkingSupport() {
+			t.Error("expected HasThinkingSupport to return true")
+		}
+	})
+
+	t.Run("with thinking disabled", func(t *testing.T) {
+		p := &Nemotron3NanoParser{HasThinking: false}
+		if p.HasThinkingSupport() {
+			t.Error("expected HasThinkingSupport to return false")
+		}
+	})
+}
+
+func TestNemotron3NanoParser_Init(t *testing.T) {
+	t.Run("starts in thinking state when enabled", func(t *testing.T) {
+		p := &Nemotron3NanoParser{HasThinking: true}
+		p.Init(nil, nil, &api.ThinkValue{Value: true})
+		if p.state != Nemotron3NanoCollectingThinking {
+			t.Errorf("expected state Nemotron3NanoCollectingThinking, got %v", p.state)
+		}
+	})
+
+	t.Run("starts in content state when thinking disabled", func(t *testing.T) {
+		p := &Nemotron3NanoParser{HasThinking: true}
+		p.Init(nil, nil, &api.ThinkValue{Value: false})
+		if p.state != Nemotron3NanoCollectingContent {
+			t.Errorf("expected state Nemotron3NanoCollectingContent, got %v", p.state)
+		}
+	})
+
+	t.Run("starts in content state when nil thinkValue", func(t *testing.T) {
+		p := &Nemotron3NanoParser{HasThinking: true}
+		p.Init(nil, nil, nil)
+		if p.state != Nemotron3NanoCollectingContent {
+			t.Errorf("expected state Nemotron3NanoCollectingContent, got %v", p.state)
+		}
+	})
+
+	t.Run("starts in content state with assistant prefill", func(t *testing.T) {
+		p := &Nemotron3NanoParser{HasThinking: true}
+		prefill := &api.Message{Role: "assistant", Content: "Starting..."}
+		p.Init(nil, prefill, &api.ThinkValue{Value: true})
+		if p.state != Nemotron3NanoCollectingContent {
+			t.Errorf("expected state Nemotron3NanoCollectingContent, got %v", p.state)
+		}
+	})
+}
+
+func TestNemotron3NanoParser_WithTools(t *testing.T) {
+	tools := []api.Tool{
+		{
+			Type: "function",
+			Function: api.ToolFunction{
+				Name: "get_weather",
+				Parameters: api.ToolFunctionParameters{
+					Type: "object",
+					Properties: map[string]api.ToolProperty{
+						"city": {Type: api.PropertyType{"string"}},
+					},
+				},
+			},
+		},
+	}
+
+	p := &Nemotron3NanoParser{}
+	returnedTools := p.Init(tools, nil, nil)
+
+	if diff := cmp.Diff(returnedTools, tools); diff != "" {
+		t.Errorf("tools mismatch (-got +want):\n%s", diff)
+	}
+
+	// Parse a tool call
+	input := "<tool_call>\n<function=get_weather>\n<parameter=city>\nParis\n</parameter>\n</function>\n</tool_call>"
+	_, _, calls, err := p.Add(input, true)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	expectedCalls := []api.ToolCall{
+		{
+			Function: api.ToolCallFunction{
+				Name:      "get_weather",
+				Arguments: map[string]any{"city": "Paris"},
+			},
+		},
+	}
+
+	if diff := cmp.Diff(calls, expectedCalls); diff != "" {
+		t.Errorf("calls mismatch (-got +want):\n%s", diff)
+	}
+}

model/parsers/parsers.go

@@ -63,9 +63,9 @@ func ParserForName(name string) Parser {
 	case "olmo3-think":
 		return &Olmo3ThinkParser{}
 	case "nemotron-3-nano":
-		return &Nemotron3NanoParser{hasThinkingSupport: false}
+		return &Nemotron3NanoParser{HasThinking: false}
 	case "nemotron-3-nano-thinking":
-		return &Nemotron3NanoParser{hasThinkingSupport: true}
+		return &Nemotron3NanoParser{HasThinking: true}
 	default:
 		return nil
 	}

model/renderers/nemotron3nano.go

@@ -18,17 +18,6 @@ func (r *Nemotron3NanoRenderer) Render(messages []api.Message, tools []api.Tool,
 	// thinking is enabled: model must support it AND user must request it
 	enableThinking := r.IsThinking && (thinkValue != nil && thinkValue.Bool())
 
-	// truncate_history_thinking: drop thinking from historical assistant messages
-	truncateHistoryThinking := true
-
-	// Find the last user message index
-	lastUserIdx := -1
-	for i, msg := range messages {
-		if msg.Role == "user" {
-			lastUserIdx = i
-		}
-	}
-
 	// Extract system message if present
 	var systemMessage string
 	var loopMessages []api.Message
@@ -39,16 +28,14 @@ func (r *Nemotron3NanoRenderer) Render(messages []api.Message, tools []api.Tool,
 		loopMessages = messages
 	}
 
-	// Recalculate lastUserIdx for loopMessages
-	lastUserIdxInLoop := -1
+	// Find last user message index for thinking truncation
+	lastUserIdx := -1
 	for i, msg := range loopMessages {
 		if msg.Role == "user" {
-			lastUserIdxInLoop = i
+			lastUserIdx = i
 		}
 	}
-	_ = lastUserIdx // silence unused variable warning
 
-	// Write system message - always include the system block
 	sb.WriteString("<|im_start|>system\n")
 	if systemMessage != "" {
 		sb.WriteString(systemMessage)
@@ -65,79 +52,18 @@ func (r *Nemotron3NanoRenderer) Render(messages []api.Message, tools []api.Tool,
 	for i, message := range loopMessages {
 		switch message.Role {
 		case "assistant":
-			// Build content with reasoning handling
-			var content string
-			if message.Thinking != "" {
-				content = "<think>\n" + message.Thinking + "\n</think>\n" + message.Content
-			} else {
-				content = message.Content
-				// Allow downstream logic to handle broken thought, only handle coherent reasoning here
-				if !strings.Contains(content, "<think>") && !strings.Contains(content, "</think>") {
-					content = "<think></think>" + content
-				}
-			}
+			// Build content with thinking tags
+			content := r.buildContent(message)
+			shouldTruncate := i < lastUserIdx
 
 			if len(message.ToolCalls) > 0 {
-				// Assistant message with tool calls
 				sb.WriteString("<|im_start|>assistant\n")
-
-				includeContent := !(truncateHistoryThinking && i < lastUserIdxInLoop)
-				if content != "" {
-					if includeContent {
-						sb.WriteString(strings.TrimSpace(content) + "\n")
-					} else {
-						// Truncate thinking
-						c := content
-						if strings.Contains(c, "</think>") {
-							// Keep only content after the last closing think
-							parts := strings.Split(c, "</think>")
-							c = parts[len(parts)-1]
-						} else if strings.Contains(c, "<think>") {
-							// If <think> was opened but never closed, drop the trailing think segment
-							parts := strings.Split(c, "<think>")
-							c = parts[0]
-						}
-						c = "<think></think>" + strings.TrimSpace(c)
-						if len(c) > len("<think></think>") {
-							sb.WriteString(c + "\n")
-						} else {
-							sb.WriteString("<think></think>")
-						}
-					}
-				} else {
-					sb.WriteString("<think></think>")
-				}
-
-				// Write tool calls
-				for _, toolCall := range message.ToolCalls {
-					sb.WriteString("<tool_call>\n<function=" + toolCall.Function.Name + ">\n")
-					for argName, argValue := range toolCall.Function.Arguments {
-						sb.WriteString("<parameter=" + argName + ">\n")
-						valueStr := r.formatArgValue(argValue)
-						sb.WriteString(valueStr + "\n</parameter>\n")
-					}
-					sb.WriteString("</function>\n</tool_call>\n")
-				}
+				sb.WriteString(r.formatContent(content, shouldTruncate, true))
+				r.writeToolCalls(&sb, message.ToolCalls)
 				sb.WriteString("<|im_end|>\n")
 			} else {
-				// Assistant message without tool calls
-				if !(truncateHistoryThinking && i < lastUserIdxInLoop) {
-					sb.WriteString("<|im_start|>assistant\n" + strings.TrimSpace(content) + "<|im_end|>\n")
-				} else {
-					// Truncate thinking - keep only content after </think>
-					c := content
-					if strings.Contains(c, "<think>") && strings.Contains(c, "</think>") {
-						parts := strings.Split(c, "</think>")
-						// Trim the content after </think> before concatenating
-						c = "<think></think>" + strings.TrimSpace(parts[len(parts)-1])
-					}
-					c = strings.TrimSpace(c)
-					if c != "" {
-						sb.WriteString("<|im_start|>assistant\n" + c + "<|im_end|>\n")
-					} else {
-						sb.WriteString("<|im_start|>assistant\n<|im_end|>\n")
-					}
-				}
+				formatted := r.formatContent(content, shouldTruncate, false)
+				sb.WriteString("<|im_start|>assistant\n" + formatted + "<|im_end|>\n")
 			}
 
 		case "user", "system":
@@ -234,6 +160,59 @@ func (r *Nemotron3NanoRenderer) renderTools(tools []api.Tool) string {
 	return sb.String()
 }
 
+func (r *Nemotron3NanoRenderer) buildContent(message api.Message) string {
+	if message.Thinking != "" {
+		return "<think>\n" + message.Thinking + "\n</think>\n" + message.Content
+	}
+	content := message.Content
+	if !strings.Contains(content, "<think>") && !strings.Contains(content, "</think>") {
+		return "<think></think>" + content
+	}
+	return content
+}
+
+func (r *Nemotron3NanoRenderer) formatContent(content string, truncate bool, addNewline bool) string {
+	if content == "" {
+		return "<think></think>"
+	}
+
+	if !truncate {
+		if addNewline {
+			return strings.TrimSpace(content) + "\n"
+		}
+		return strings.TrimSpace(content)
+	}
+
+	// Truncate thinking - keep only content after </think>
+	c := content
+	if strings.Contains(c, "</think>") {
+		parts := strings.Split(c, "</think>")
+		c = parts[len(parts)-1]
+	} else if strings.Contains(c, "<think>") {
+		parts := strings.Split(c, "<think>")
+		c = parts[0]
+	}
+	c = "<think></think>" + strings.TrimSpace(c)
+
+	if addNewline && len(c) > len("<think></think>") {
+		return c + "\n"
+	}
+	if c == "<think></think>" {
+		return c
+	}
+	return strings.TrimSpace(c)
+}
+
+func (r *Nemotron3NanoRenderer) writeToolCalls(sb *strings.Builder, toolCalls []api.ToolCall) {
+	for _, tc := range toolCalls {
+		sb.WriteString("<tool_call>\n<function=" + tc.Function.Name + ">\n")
+		for name, value := range tc.Function.Arguments {
+			sb.WriteString("<parameter=" + name + ">\n" + r.formatArgValue(value) + "\n</parameter>\n")
+		}
+		sb.WriteString("</function>\n</tool_call>\n")
+	}
+}
+
 func (r *Nemotron3NanoRenderer) formatArgValue(value any) string {
 	switch v := value.(type) {
 	case map[string]any, []any:

model/renderers/nemotron3nano_test.go

@@ -0,0 +1,404 @@
+package renderers
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+
+	"github.com/ollama/ollama/api"
+)
+
+func TestNemotron3NanoRenderer(t *testing.T) {
+	tests := []struct {
+		name       string
+		msgs       []api.Message
+		tools      []api.Tool
+		thinkValue *api.ThinkValue
+		isThinking bool
+		expected   string
+	}{
+		{
+			name: "basic user message - thinking mode",
+			msgs: []api.Message{
+				{Role: "user", Content: "Hello!"},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\n<|im_end|>\n" +
+				"<|im_start|>user\nHello!<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+		{
+			name: "basic user message - no thinking",
+			msgs: []api.Message{
+				{Role: "user", Content: "Hello!"},
+			},
+			isThinking: false,
+			expected: "<|im_start|>system\n<|im_end|>\n" +
+				"<|im_start|>user\nHello!<|im_end|>\n" +
+				"<|im_start|>assistant\n<think></think>",
+		},
+		{
+			name: "with system message",
+			msgs: []api.Message{
+				{Role: "system", Content: "You are a helpful assistant."},
+				{Role: "user", Content: "Hello!"},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\nYou are a helpful assistant.<|im_end|>\n" +
+				"<|im_start|>user\nHello!<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+		{
+			name: "multi-turn conversation",
+			msgs: []api.Message{
+				{Role: "user", Content: "Hi"},
+				{Role: "assistant", Content: "Hello! How can I help?"},
+				{Role: "user", Content: "Tell me a joke"},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\n<|im_end|>\n" +
+				"<|im_start|>user\nHi<|im_end|>\n" +
+				"<|im_start|>assistant\n<think></think>Hello! How can I help?<|im_end|>\n" +
+				"<|im_start|>user\nTell me a joke<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+		{
+			name: "with tools",
+			msgs: []api.Message{
+				{Role: "user", Content: "What's the weather in Paris?"},
+			},
+			tools: []api.Tool{
+				{
+					Type: "function",
+					Function: api.ToolFunction{
+						Name:        "get_weather",
+						Description: "Get the current weather",
+						Parameters: api.ToolFunctionParameters{
+							Type:     "object",
+							Required: []string{"city"},
+							Properties: map[string]api.ToolProperty{
+								"city": {Type: api.PropertyType{"string"}, Description: "The city name"},
+							},
+						},
+					},
+				},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\n" +
+				"# Tools\n\nYou have access to the following functions:\n\n<tools>\n" +
+				"<function>\n<name>get_weather</name>\n" +
+				"<description>Get the current weather</description>\n" +
+				"<parameters>\n" +
+				"<parameter>\n<name>city</name>\n<type>string</type>\n<description>The city name</description>\n</parameter>\n" +
+				"<required>[\"city\"]</required>\n" +
+				"</parameters>\n</function>\n</tools>\n\n" +
+				"If you choose to call a function ONLY reply in the following format with NO suffix:\n\n" +
+				"<tool_call>\n<function=example_function_name>\n<parameter=example_parameter_1>\nvalue_1\n</parameter>\n" +
+				"<parameter=example_parameter_2>\nThis is the value for the second parameter\nthat can span\nmultiple lines\n" +
+				"</parameter>\n</function>\n</tool_call>\n\n<IMPORTANT>\nReminder:\n" +
+				"- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags\n" +
+				"- Required parameters MUST be specified\n" +
+				"- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after\n" +
+				"- If there is no function call available, answer the question like normal with your current knowledge and do not tell the user about function calls\n" +
+				"</IMPORTANT><|im_end|>\n" +
+				"<|im_start|>user\nWhat's the weather in Paris?<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+		{
+			name: "tool call with response",
+			msgs: []api.Message{
+				{Role: "user", Content: "What's the weather in Paris?"},
+				{
+					Role: "assistant",
+					ToolCalls: []api.ToolCall{
+						{
+							Function: api.ToolCallFunction{
+								Name:      "get_weather",
+								Arguments: map[string]any{"city": "Paris"},
+							},
+						},
+					},
+				},
+				{Role: "tool", Content: "Sunny, 72F"},
+			},
+			tools: []api.Tool{
+				{
+					Type: "function",
+					Function: api.ToolFunction{
+						Name:        "get_weather",
+						Description: "Get the current weather",
+						Parameters: api.ToolFunctionParameters{
+							Type:     "object",
+							Required: []string{"city"},
+							Properties: map[string]api.ToolProperty{
+								"city": {Type: api.PropertyType{"string"}, Description: "The city name"},
+							},
+						},
+					},
+				},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\n" +
+				"# Tools\n\nYou have access to the following functions:\n\n<tools>\n" +
+				"<function>\n<name>get_weather</name>\n" +
+				"<description>Get the current weather</description>\n" +
+				"<parameters>\n" +
+				"<parameter>\n<name>city</name>\n<type>string</type>\n<description>The city name</description>\n</parameter>\n" +
+				"<required>[\"city\"]</required>\n" +
+				"</parameters>\n</function>\n</tools>\n\n" +
+				"If you choose to call a function ONLY reply in the following format with NO suffix:\n\n" +
+				"<tool_call>\n<function=example_function_name>\n<parameter=example_parameter_1>\nvalue_1\n</parameter>\n" +
+				"<parameter=example_parameter_2>\nThis is the value for the second parameter\nthat can span\nmultiple lines\n" +
+				"</parameter>\n</function>\n</tool_call>\n\n<IMPORTANT>\nReminder:\n" +
+				"- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags\n" +
+				"- Required parameters MUST be specified\n" +
+				"- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after\n" +
+				"- If there is no function call available, answer the question like normal with your current knowledge and do not tell the user about function calls\n" +
+				"</IMPORTANT><|im_end|>\n" +
+				"<|im_start|>user\nWhat's the weather in Paris?<|im_end|>\n" +
+				"<|im_start|>assistant\n<think></think>\n" +
+				"<tool_call>\n<function=get_weather>\n<parameter=city>\nParis\n</parameter>\n</function>\n</tool_call>\n<|im_end|>\n" +
+				"<|im_start|>user\n<tool_response>\nSunny, 72F\n</tool_response>\n<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+		{
+			name: "assistant with content and tool call",
+			msgs: []api.Message{
+				{Role: "user", Content: "What's the weather?"},
+				{
+					Role:    "assistant",
+					Content: "Let me check that for you.",
+					ToolCalls: []api.ToolCall{
+						{
+							Function: api.ToolCallFunction{
+								Name:      "get_weather",
+								Arguments: map[string]any{"city": "Paris"},
+							},
+						},
+					},
+				},
+				{Role: "tool", Content: "Sunny"},
+			},
+			tools: []api.Tool{
+				{
+					Type: "function",
+					Function: api.ToolFunction{
+						Name: "get_weather",
+						Parameters: api.ToolFunctionParameters{
+							Type: "object",
+							Properties: map[string]api.ToolProperty{
+								"city": {Type: api.PropertyType{"string"}},
+							},
+						},
+					},
+				},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\n" +
+				"# Tools\n\nYou have access to the following functions:\n\n<tools>\n" +
+				"<function>\n<name>get_weather</name>\n" +
+				"<parameters>\n" +
+				"<parameter>\n<name>city</name>\n<type>string</type>\n</parameter>\n" +
+				"</parameters>\n</function>\n</tools>\n\n" +
+				"If you choose to call a function ONLY reply in the following format with NO suffix:\n\n" +
+				"<tool_call>\n<function=example_function_name>\n<parameter=example_parameter_1>\nvalue_1\n</parameter>\n" +
+				"<parameter=example_parameter_2>\nThis is the value for the second parameter\nthat can span\nmultiple lines\n" +
+				"</parameter>\n</function>\n</tool_call>\n\n<IMPORTANT>\nReminder:\n" +
+				"- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags\n" +
+				"- Required parameters MUST be specified\n" +
+				"- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after\n" +
+				"- If there is no function call available, answer the question like normal with your current knowledge and do not tell the user about function calls\n" +
+				"</IMPORTANT><|im_end|>\n" +
+				"<|im_start|>user\nWhat's the weather?<|im_end|>\n" +
+				"<|im_start|>assistant\n<think></think>Let me check that for you.\n" +
+				"<tool_call>\n<function=get_weather>\n<parameter=city>\nParis\n</parameter>\n</function>\n</tool_call>\n<|im_end|>\n" +
+				"<|im_start|>user\n<tool_response>\nSunny\n</tool_response>\n<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+		{
+			name: "thinking in history is truncated",
+			msgs: []api.Message{
+				{Role: "user", Content: "Hi"},
+				{Role: "assistant", Content: "Hello!", Thinking: "Let me think about this..."},
+				{Role: "user", Content: "How are you?"},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\n<|im_end|>\n" +
+				"<|im_start|>user\nHi<|im_end|>\n" +
+				"<|im_start|>assistant\n<think></think>Hello!<|im_end|>\n" +
+				"<|im_start|>user\nHow are you?<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+		{
+			name: "parallel tool calls",
+			msgs: []api.Message{
+				{Role: "user", Content: "Weather in Paris and London?"},
+				{
+					Role: "assistant",
+					ToolCalls: []api.ToolCall{
+						{
+							Function: api.ToolCallFunction{
+								Name:      "get_weather",
+								Arguments: map[string]any{"city": "Paris"},
+							},
+						},
+						{
+							Function: api.ToolCallFunction{
+								Name:      "get_weather",
+								Arguments: map[string]any{"city": "London"},
+							},
+						},
+					},
+				},
+				{Role: "tool", Content: "Sunny"},
+				{Role: "tool", Content: "Rainy"},
+			},
+			tools: []api.Tool{
+				{
+					Type: "function",
+					Function: api.ToolFunction{
+						Name: "get_weather",
+						Parameters: api.ToolFunctionParameters{
+							Type: "object",
+							Properties: map[string]api.ToolProperty{
+								"city": {Type: api.PropertyType{"string"}},
+							},
+						},
+					},
+				},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\n" +
+				"# Tools\n\nYou have access to the following functions:\n\n<tools>\n" +
+				"<function>\n<name>get_weather</name>\n" +
+				"<parameters>\n" +
+				"<parameter>\n<name>city</name>\n<type>string</type>\n</parameter>\n" +
+				"</parameters>\n</function>\n</tools>\n\n" +
+				"If you choose to call a function ONLY reply in the following format with NO suffix:\n\n" +
+				"<tool_call>\n<function=example_function_name>\n<parameter=example_parameter_1>\nvalue_1\n</parameter>\n" +
+				"<parameter=example_parameter_2>\nThis is the value for the second parameter\nthat can span\nmultiple lines\n" +
+				"</parameter>\n</function>\n</tool_call>\n\n<IMPORTANT>\nReminder:\n" +
+				"- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags\n" +
+				"- Required parameters MUST be specified\n" +
+				"- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after\n" +
+				"- If there is no function call available, answer the question like normal with your current knowledge and do not tell the user about function calls\n" +
+				"</IMPORTANT><|im_end|>\n" +
+				"<|im_start|>user\nWeather in Paris and London?<|im_end|>\n" +
+				"<|im_start|>assistant\n<think></think>\n" +
+				"<tool_call>\n<function=get_weather>\n<parameter=city>\nParis\n</parameter>\n</function>\n</tool_call>\n" +
+				"<tool_call>\n<function=get_weather>\n<parameter=city>\nLondon\n</parameter>\n</function>\n</tool_call>\n<|im_end|>\n" +
+				"<|im_start|>user\n<tool_response>\nSunny\n</tool_response>\n<tool_response>\nRainy\n</tool_response>\n<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+		{
+			name: "thinking disabled even when model supports it",
+			msgs: []api.Message{
+				{Role: "user", Content: "Hello!"},
+			},
+			isThinking: true, // model supports thinking
+			thinkValue: nil,  // but user didn't request it
+			expected: "<|im_start|>system\n<|im_end|>\n" +
+				"<|im_start|>user\nHello!<|im_end|>\n" +
+				"<|im_start|>assistant\n<think></think>",
+		},
+		{
+			name: "complex message history with thinking, tools, tool calls, tool results and content",
+			msgs: []api.Message{
+				{Role: "user", Content: "What's the weather in Paris and London? Also, what's 2+2?"},
+				{Role: "assistant", Content: "", Thinking: "I need to check the weather for both cities and calculate 2+2. Let me start with the weather calls.", ToolCalls: []api.ToolCall{
+					{Function: api.ToolCallFunction{Name: "get_weather", Arguments: api.ToolCallFunctionArguments{"city": "Paris"}}},
+					{Function: api.ToolCallFunction{Name: "get_weather", Arguments: api.ToolCallFunctionArguments{"city": "London"}}},
+				}},
+				{Role: "tool", Content: "Sunny, 22°C", ToolCallID: "call1"},
+				{Role: "tool", Content: "Rainy, 15°C", ToolCallID: "call2"},
+				{Role: "assistant", Content: "", Thinking: "Now I have the weather data. Let me calculate 2+2.", ToolCalls: []api.ToolCall{
+					{Function: api.ToolCallFunction{Name: "calculate", Arguments: api.ToolCallFunctionArguments{"expression": "2+2"}}},
+				}},
+				{Role: "tool", Content: "4", ToolCallID: "call3"},
+				{Role: "assistant", Content: "Based on the weather data, Paris is sunny at 22°C and London is rainy at 15°C. Also, 2+2 equals 4.", Thinking: "Perfect! I have all the information needed to provide a complete answer."},
+			},
+			tools: []api.Tool{
+				{
+					Type: "function",
+					Function: api.ToolFunction{
+						Name: "get_weather",
+						Parameters: api.ToolFunctionParameters{
+							Type: "object",
+							Properties: map[string]api.ToolProperty{
+								"city": {Type: api.PropertyType{"string"}},
+							},
+						},
+					},
+				},
+				{
+					Type: "function",
+					Function: api.ToolFunction{
+						Name: "calculate",
+						Parameters: api.ToolFunctionParameters{
+							Type: "object",
+							Properties: map[string]api.ToolProperty{
+								"expression": {Type: api.PropertyType{"string"}},
+							},
+						},
+					},
+				},
+			},
+			isThinking: true,
+			thinkValue: &api.ThinkValue{Value: true},
+			expected: "<|im_start|>system\n" +
+				"# Tools\n\nYou have access to the following functions:\n\n<tools>\n" +
+				"<function>\n<name>get_weather</name>\n" +
+				"<parameters>\n" +
+				"<parameter>\n<name>city</name>\n<type>string</type>\n</parameter>\n" +
+				"</parameters>\n</function>\n" +
+				"<function>\n<name>calculate</name>\n" +
+				"<parameters>\n" +
+				"<parameter>\n<name>expression</name>\n<type>string</type>\n</parameter>\n" +
+				"</parameters>\n</function>\n</tools>\n\n" +
+				"If you choose to call a function ONLY reply in the following format with NO suffix:\n\n" +
+				"<tool_call>\n<function=example_function_name>\n<parameter=example_parameter_1>\nvalue_1\n</parameter>\n" +
+				"<parameter=example_parameter_2>\nThis is the value for the second parameter\nthat can span\nmultiple lines\n" +
+				"</parameter>\n</function>\n</tool_call>\n\n<IMPORTANT>\nReminder:\n" +
+				"- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags\n" +
+				"- Required parameters MUST be specified\n" +
+				"- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after\n" +
+				"- If there is no function call available, answer the question like normal with your current knowledge and do not tell the user about function calls\n" +
+				"</IMPORTANT><|im_end|>\n" +
+				"<|im_start|>user\nWhat's the weather in Paris and London? Also, what's 2+2?<|im_end|>\n" +
+				"<|im_start|>assistant\n" +
+				"<think>\nI need to check the weather for both cities and calculate 2+2. Let me start with the weather calls.\n</think>\n" +
+				"<tool_call>\n<function=get_weather>\n<parameter=city>\nParis\n</parameter>\n</function>\n</tool_call>\n" +
+				"<tool_call>\n<function=get_weather>\n<parameter=city>\nLondon\n</parameter>\n</function>\n</tool_call>\n<|im_end|>\n" +
+				"<|im_start|>user\n<tool_response>\nSunny, 22°C\n</tool_response>\n<tool_response>\nRainy, 15°C\n</tool_response>\n<|im_end|>\n" +
+				"<|im_start|>assistant\n" +
+				"<think>\nNow I have the weather data. Let me calculate 2+2.\n</think>\n" +
+				"<tool_call>\n<function=calculate>\n<parameter=expression>\n2+2\n</parameter>\n</function>\n</tool_call>\n<|im_end|>\n" +
+				"<|im_start|>user\n<tool_response>\n4\n</tool_response>\n<|im_end|>\n" +
+				"<|im_start|>assistant\n" +
+				"<think>\nPerfect! I have all the information needed to provide a complete answer.\n</think>\n" +
+				"Based on the weather data, Paris is sunny at 22°C and London is rainy at 15°C. Also, 2+2 equals 4.<|im_end|>\n" +
+				"<|im_start|>assistant\n<think>\n",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			renderer := &Nemotron3NanoRenderer{IsThinking: tt.isThinking}
+			rendered, err := renderer.Render(tt.msgs, tt.tools, tt.thinkValue)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if diff := cmp.Diff(rendered, tt.expected); diff != "" {
+				t.Errorf("mismatch (-got +want):\n%s", diff)
+			}
+		})
+	}
+}