sampler/runner: enable gpt-oss structured outputs

harmony/harmonyparser.go

@@ -1,17 +1,32 @@
 package harmony
 
 import (
+	"encoding/json"
 	"fmt"
 	"log/slog"
+	"maps"
+	"slices"
 	"strings"
 	"unicode"
 
-	"github.com/ollama/ollama/api"
 	"github.com/ollama/ollama/logutil"
+	"github.com/ollama/ollama/template"
 )
 
 type harmonyParserState int
 
+func ShouldUseHarmony(modelFamily string, template *template.Template) bool {
+	if slices.Contains([]string{"gptoss", "gpt-oss"}, modelFamily) {
+		// heuristic to check whether the template expects to be parsed via harmony:
+		// search for harmony tags that are nearly always used
+		if template.Contains("<|start|>") && template.Contains("<|end|>") {
+			return true
+		}
+	}
+
+	return false
+}
+
 const (
 	harmonyParserState_LookingForMessageStart harmonyParserState = iota
 	harmonyParserState_ParsingHeader
@@ -33,12 +48,13 @@ func (s harmonyParserState) String() string {
 }
 
 type HarmonyParser struct {
-	state           harmonyParserState
+	state            harmonyParserState
-	MessageStartTag string
+	MessageStartTag  string
-	MessageEndTag   string
+	MessageEndTag    string
-	HeaderEndTag    string
+	HeaderEndTag     string
-	acc             strings.Builder
+	ConstrainAllowed bool
-	lifetimeAcc     strings.Builder
+	acc              strings.Builder
+	lifetimeAcc      strings.Builder
 }
 
 type HarmonyEvent interface {
@@ -75,17 +91,18 @@ func (s *HarmonyParser) AddImplicitStart() {
 	s.acc.WriteString("<|start|>assistant")
 }
 
-func (s *HarmonyParser) AddImplicitStartOrPrefill(lastMessage *api.Message) {
+// AddImplicitStartOrPrefill adds content or thinking to the accumulator else adds start tag
-	if lastMessage != nil && lastMessage.Role == "assistant" {
+func (s *HarmonyParser) AddImplicitStartOrPrefill(prefillContentOrThinking *bool) {
-		// handle prefilling conditions
+	if prefillContentOrThinking != nil {
-		if lastMessage.Content != "" {
+		if *prefillContentOrThinking {
 			s.acc.WriteString("<|start|>assistant<|channel|>final<|message|>")
 			return
-		} else if lastMessage.Thinking != "" {
+		} else {
 			s.acc.WriteString("<|start|>assistant<|channel|>analysis<|message|>")
 			return
 		}
 	}
+
 	s.AddImplicitStart()
 }
 
@@ -312,6 +329,7 @@ func (h *HarmonyMessageHandler) AddContent(content string, toolParser *HarmonyTo
 				}
 			case "final":
 				h.state = harmonyMessageState_Normal
+				h.HarmonyParser.ConstrainAllowed = true
 			}
 		case HarmonyEventContentEmitted:
 			logutil.Trace("harmony event content", "content", event.Content, "state", h.state)
@@ -377,6 +395,38 @@ type FunctionNameMap struct {
 	harmonyToUser map[string]string
 }
 
+func (m FunctionNameMap) MarshalJSON() ([]byte, error) {
+	// necessary to avoid exposing map internals
+	type alias struct {
+		UserToHarmony map[string]string `json:"userToHarmony"`
+		HarmonyToUser map[string]string `json:"harmonyToUser"`
+	}
+	return json.Marshal(alias{
+		UserToHarmony: m.userToHarmony,
+		HarmonyToUser: m.harmonyToUser,
+	})
+}
+
+func (m *FunctionNameMap) UnmarshalJSON(b []byte) error {
+	type alias struct {
+		UserToHarmony map[string]string `json:"userToHarmony"`
+		HarmonyToUser map[string]string `json:"harmonyToUser"`
+	}
+	var a alias
+	if err := json.Unmarshal(b, &a); err != nil {
+		return err
+	}
+	if m.userToHarmony == nil {
+		m.userToHarmony = make(map[string]string)
+	}
+	if m.harmonyToUser == nil {
+		m.harmonyToUser = make(map[string]string)
+	}
+	maps.Copy(m.userToHarmony, a.UserToHarmony)
+	maps.Copy(m.harmonyToUser, a.HarmonyToUser)
+	return nil
+}
+
 func NewFunctionNameMap() *FunctionNameMap {
 	return &FunctionNameMap{
 		userToHarmony: make(map[string]string),

harmony/harmonyparser_test.go

@@ -1,8 +1,10 @@
 package harmony
 
 import (
+	"encoding/json"
 	"fmt"
 	"reflect"
+	"strings"
 	"testing"
 )
 
@@ -535,3 +537,224 @@ func TestFunctionConvertAndAdd(t *testing.T) {
 		})
 	}
 }
+
+func TestHarmonyMessageHandlerStreamingScenarios(t *testing.T) {
+	t.Run("thinking_then_content_streams", func(t *testing.T) {
+		handler := NewHarmonyMessageHandler()
+		handler.HarmonyParser.AddImplicitStart()
+		tp := handler.CreateToolParser()
+		type step struct {
+			in           string
+			wantContent  string
+			wantThinking string
+		}
+		steps := []step{
+			{in: "<|channel|>analysis<|message|>Thinking...", wantThinking: "Thinking..."},
+			{in: "<|end|>", wantThinking: ""},
+			{in: "<|start|>assistant<|message|>Answer", wantContent: "Answer"},
+			{in: "<|end|>", wantContent: ""},
+		}
+		for i, s := range steps {
+			content, thinking, tool := handler.AddContent(s.in, tp)
+			if tool != "" {
+				tp.Add(tool)
+			}
+			if content != s.wantContent || thinking != s.wantThinking {
+				t.Fatalf("step %d: got (content=%q thinking=%q), want (content=%q thinking=%q)", i, content, thinking, s.wantContent, s.wantThinking)
+			}
+		}
+	})
+
+	t.Run("content_streams_as_it_arrives", func(t *testing.T) {
+		handler := NewHarmonyMessageHandler()
+		handler.HarmonyParser.AddImplicitStart()
+		tp := handler.CreateToolParser()
+		inputs := []string{
+			"<|start|>assistant<|message|>Hello",
+			", world",
+			"!<|end|>",
+		}
+		var got []string
+		for _, in := range inputs {
+			content, thinking, tool := handler.AddContent(in, tp)
+			if tool != "" {
+				tp.Add(tool)
+			}
+			if thinking != "" {
+				t.Fatalf("unexpected thinking %q", thinking)
+			}
+			if content != "" {
+				got = append(got, content)
+			}
+		}
+		want := []string{"Hello", ", world", "!"}
+		if !reflect.DeepEqual(got, want) {
+			t.Fatalf("content pieces mismatch: got %v want %v", got, want)
+		}
+	})
+
+	t.Run("thinking_streams_separately_from_content", func(t *testing.T) {
+		handler := NewHarmonyMessageHandler()
+		handler.HarmonyParser.AddImplicitStart()
+		tp := handler.CreateToolParser()
+		inputs := []string{
+			"<|channel|>analysis<|message|>Thinking...",
+			"<|end|>",
+			"<|start|>assistant<|message|>Answer",
+			"<|end|>",
+		}
+		var got []string
+		for _, in := range inputs {
+			content, thinking, tool := handler.AddContent(in, tp)
+			if tool != "" {
+				tp.Add(tool)
+			}
+			if thinking != "" {
+				got = append(got, thinking)
+			}
+			if content != "" {
+				got = append(got, content)
+			}
+		}
+		want := []string{"Thinking...", "Answer"}
+		if !reflect.DeepEqual(got, want) {
+			t.Fatalf("content pieces mismatch: got %v want %v", got, want)
+		}
+	})
+
+	t.Run("partial_tags_buffer_until_complete", func(t *testing.T) {
+		handler := NewHarmonyMessageHandler()
+		handler.HarmonyParser.AddImplicitStart()
+		tp := handler.CreateToolParser()
+		inputs := []string{
+			"<|chan",
+			"nel|>analysis<|mess",
+			"age|>Deep ",
+			"thought",
+			"<|end|>",
+			"<|start|>assistant<|message|>Done",
+			"<|end|>",
+		}
+		var thinkingPieces []string
+		var contentPieces []string
+		for _, in := range inputs {
+			content, thinking, tool := handler.AddContent(in, tp)
+			if tool != "" {
+				tp.Add(tool)
+			}
+			if thinking != "" {
+				thinkingPieces = append(thinkingPieces, thinking)
+			}
+			if content != "" {
+				contentPieces = append(contentPieces, content)
+			}
+		}
+		if want := []string{"Deep ", "thought"}; !reflect.DeepEqual(thinkingPieces, want) {
+			t.Fatalf("thinking pieces mismatch: got %v want %v", thinkingPieces, want)
+		}
+		if want := []string{"Done"}; !reflect.DeepEqual(contentPieces, want) {
+			t.Fatalf("content pieces mismatch: got %v want %v", contentPieces, want)
+		}
+	})
+
+	t.Run("simple_assistant_after_analysis", func(t *testing.T) {
+		handler := NewHarmonyMessageHandler()
+		handler.HarmonyParser.AddImplicitStart()
+		tp := handler.CreateToolParser()
+		inputs := []string{
+			"<|channel|>analysis<|message|>Think",
+			"<|end|>",
+			"<|start|>assistant<|message|>Answer",
+			"<|end|>",
+		}
+		var contentSb, thinkingSb strings.Builder
+		for _, in := range inputs {
+			content, thinking, tool := handler.AddContent(in, tp)
+			if tool != "" {
+				tp.Add(tool)
+			}
+			contentSb.WriteString(content)
+			thinkingSb.WriteString(thinking)
+		}
+		if contentSb.String() != "Answer" {
+			t.Fatalf("content mismatch: got %q want %q", contentSb.String(), "Answer")
+		}
+		if thinkingSb.String() != "Think" {
+			t.Fatalf("thinking mismatch: got %q want %q", thinkingSb.String(), "Think")
+		}
+	})
+
+	t.Run("tool_call_parsed_and_returned_correctly", func(t *testing.T) {
+		handler := NewHarmonyMessageHandler()
+		handler.HarmonyParser.AddImplicitStart()
+		tp := handler.CreateToolParser()
+		inputs := []string{
+			"<|channel|>commentary to=functions.calculate<|message|>{\"expression\":\"2+2\"}<|end|>",
+		}
+		for _, in := range inputs {
+			content, thinking, tool := handler.AddContent(in, tp)
+			if content != "" || thinking != "" {
+				continue
+			}
+			if tool != "" {
+				tp.Add(tool)
+			}
+		}
+		name, args := tp.Drain()
+		if name == nil || *name != "functions.calculate" {
+			t.Fatalf("unexpected tool name: %v", name)
+		}
+		if got, want := args, "{\"expression\":\"2+2\"}"; got != want {
+			t.Fatalf("unexpected tool args: got %s want %s", got, want)
+		}
+	})
+
+	t.Run("tool_call_across_chunks", func(t *testing.T) {
+		handler := NewHarmonyMessageHandler()
+		handler.HarmonyParser.AddImplicitStart()
+		tp := handler.CreateToolParser()
+		inputs := []string{
+			"<|channel|>commentary to=functions.calculate<|message|>{\"expression\":\"2+",
+			"2\"}",
+			"<|end|>",
+		}
+		for _, in := range inputs {
+			content, thinking, tool := handler.AddContent(in, tp)
+			if content != "" || thinking != "" {
+				continue
+			}
+			if tool != "" {
+				tp.Add(tool)
+			}
+		}
+		name, args := tp.Drain()
+		if name == nil || *name != "functions.calculate" {
+			t.Fatalf("unexpected tool name: %v", name)
+		}
+		if got, want := args, "{\"expression\":\"2+2\"}"; got != want {
+			t.Fatalf("unexpected tool args: got %s want %s", got, want)
+		}
+	})
+}
+
+func TestFunctionNameMapJSONRoundTrip(t *testing.T) {
+	m := NewFunctionNameMap()
+	gotConverted := m.ConvertAndAdd("get weather")
+	if gotConverted == "" {
+		t.Fatal("conversion returned empty")
+	}
+	b, err := json.Marshal(m)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	var m2 FunctionNameMap
+	if err := json.Unmarshal(b, &m2); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	if m2.userToHarmony["get weather"] != gotConverted {
+		t.Fatalf("userToHarmony lost: got %q want %q", m2.userToHarmony["get weather"], gotConverted)
+	}
+	if m2.harmonyToUser[gotConverted] != "get weather" {
+		t.Fatalf("harmonyToUser lost: got %q want %q", m2.harmonyToUser[gotConverted], "get weather")
+	}
+}

llm/server.go

@@ -1347,7 +1347,9 @@ type CompletionRequest struct {
 	Images  []ImageData
 	Options *api.Options
 
-	Grammar string // set before sending the request to the subprocess
+	Grammar        string // set before sending the request to the subprocess
+	UseHarmony     bool
+	PrefillContent *bool
 }
 
 // DoneReason represents the reason why a completion response is done
@@ -1374,13 +1376,15 @@ func (d DoneReason) String() string {
 }
 
 type CompletionResponse struct {
-	Content            string        `json:"content"`
+	Content            string         `json:"content"`
-	DoneReason         DoneReason    `json:"done_reason"`
+	Thinking           string         `json:"thinking"`
-	Done               bool          `json:"done"`
+	ToolCalls          []api.ToolCall `json:"tool_calls"`
-	PromptEvalCount    int           `json:"prompt_eval_count"`
+	DoneReason         DoneReason     `json:"done_reason"`
-	PromptEvalDuration time.Duration `json:"prompt_eval_duration"`
+	Done               bool           `json:"done"`
-	EvalCount          int           `json:"eval_count"`
+	PromptEvalCount    int            `json:"prompt_eval_count"`
-	EvalDuration       time.Duration `json:"eval_duration"`
+	PromptEvalDuration time.Duration  `json:"prompt_eval_duration"`
+	EvalCount          int            `json:"eval_count"`
+	EvalDuration       time.Duration  `json:"eval_duration"`
 }
 
 func (s *llmServer) Completion(ctx context.Context, req CompletionRequest, fn func(CompletionResponse)) error {
@@ -1498,7 +1502,7 @@ func (s *llmServer) Completion(ctx context.Context, req CompletionRequest, fn fu
 				return fmt.Errorf("error unmarshalling llm prediction response: %v", err)
 			}
 			switch {
-			case strings.TrimSpace(c.Content) == lastToken:
+			case lastToken != "" && (strings.TrimSpace(c.Content) == lastToken || strings.TrimSpace(c.Thinking) == lastToken):
 				tokenRepeat++
 			default:
 				lastToken = strings.TrimSpace(c.Content)
@@ -1511,16 +1515,14 @@ func (s *llmServer) Completion(ctx context.Context, req CompletionRequest, fn fu
 				return ctx.Err()
 			}
 
-			if c.Content != "" {
-				fn(CompletionResponse{
-					Content: c.Content,
-				})
-			}
-
 			if c.Done {
 				fn(c)
 				return nil
 			}
+
+			if c.Content != "" || c.Thinking != "" || len(c.ToolCalls) > 0 {
+				fn(c)
+			}
 		}
 	}
 

runner/ollamarunner/runner.go

@@ -29,6 +29,7 @@ import (
 
 	"github.com/ollama/ollama/api"
 	"github.com/ollama/ollama/envconfig"
+	"github.com/ollama/ollama/harmony"
 	"github.com/ollama/ollama/llm"
 	"github.com/ollama/ollama/logutil"
 	"github.com/ollama/ollama/ml"
@@ -773,6 +774,14 @@ func (s *Server) completion(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	var harmonyMessageHandler *harmony.HarmonyMessageHandler
+	var harmonyToolParser *harmony.HarmonyToolCallAccumulator
+	if req.UseHarmony {
+		harmonyMessageHandler = harmony.NewHarmonyMessageHandler()
+		harmonyMessageHandler.HarmonyParser.AddImplicitStartOrPrefill(req.PrefillContent)
+		harmonyToolParser = harmonyMessageHandler.CreateToolParser()
+	}
+
 	if req.Options == nil {
 		opts := api.DefaultOptions()
 		req.Options = &opts
@@ -805,7 +814,7 @@ func (s *Server) completion(w http.ResponseWriter, r *http.Request) {
 		req.Options.TopP,
 		req.Options.MinP,
 		req.Options.Seed,
-		grammar,
+		nil,
 	)
 
 	seq, err := s.NewSequence(req.Prompt, req.Images, NewSequenceParams{
@@ -856,6 +865,12 @@ func (s *Server) completion(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// TODO(parthsareen): generalize grammar enablement on the fly for all thinking models
+	if harmonyMessageHandler == nil {
+		seq.sampler.SetGrammar(grammar)
+	}
+
+	grammarSet := false
 	for {
 		select {
 		case <-r.Context().Done():
@@ -863,8 +878,20 @@ func (s *Server) completion(w http.ResponseWriter, r *http.Request) {
 			return
 		case content, ok := <-seq.responses:
 			if ok {
+				var thinking string
+				if harmonyMessageHandler != nil {
+					var toolContent string
+					content, thinking, toolContent = harmonyMessageHandler.AddContent(content, harmonyToolParser)
+					harmonyToolParser.Add(toolContent)
+					if harmonyMessageHandler.HarmonyParser.ConstrainAllowed && !grammarSet {
+						seq.sampler.SetGrammar(grammar)
+						grammarSet = true
+					}
+				}
+
 				if err := json.NewEncoder(w).Encode(&llm.CompletionResponse{
-					Content: content,
+					Content:  content,
+					Thinking: thinking,
 				}); err != nil {
 					http.Error(w, fmt.Sprintf("failed to encode response: %v", err), http.StatusInternalServerError)
 					close(seq.quit)
@@ -873,7 +900,29 @@ func (s *Server) completion(w http.ResponseWriter, r *http.Request) {
 
 				flusher.Flush()
 			} else {
+				var toolCalls []api.ToolCall
+				if harmonyMessageHandler != nil {
+					// these tools still need to be transformed to the original function name
+					toolName, toolContent := harmonyToolParser.Drain()
+					if toolName != nil {
+						*toolName = strings.TrimPrefix(*toolName, "functions.")
+						var args api.ToolCallFunctionArguments
+						if err := json.Unmarshal([]byte(toolContent), &args); err != nil {
+							http.Error(w, fmt.Sprintf("failed to unmarshal tool call function arguments: %v", err), http.StatusInternalServerError)
+							close(seq.quit)
+							return
+						}
+						toolCalls = append(toolCalls, api.ToolCall{
+							Function: api.ToolCallFunction{
+								Name:      *toolName,
+								Arguments: args,
+							},
+						})
+					}
+				}
+
 				if err := json.NewEncoder(w).Encode(&llm.CompletionResponse{
+					ToolCalls:          toolCalls,
 					Done:               true,
 					DoneReason:         seq.doneReason,
 					PromptEvalCount:    seq.numPromptInputs,

sample/samplers.go

@@ -25,6 +25,10 @@ type Sampler struct {
 	grammar     *GrammarSampler
 }
 
+func (s *Sampler) SetGrammar(grammar *GrammarSampler) {
+	s.grammar = grammar
+}
+
 func (s *Sampler) Sample(logits []float32) (int32, error) {
 	if len(logits) == 0 {
 		return -1, errors.New("sample: no logits provided to sample")

server/routes.go

@@ -46,18 +46,6 @@ import (
 	"github.com/ollama/ollama/version"
 )
 
-func shouldUseHarmony(model *Model) bool {
-	if slices.Contains([]string{"gptoss", "gpt-oss"}, model.Config.ModelFamily) {
-		// heuristic to check whether the template expects to be parsed via harmony:
-		// search for harmony tags that are nearly always used
-		if model.Template.Contains("<|start|>") && model.Template.Contains("<|end|>") {
-			return true
-		}
-	}
-
-	return false
-}
-
 func experimentEnabled(name string) bool {
 	return slices.Contains(strings.Split(os.Getenv("OLLAMA_EXPERIMENT"), ","), name)
 }
@@ -207,13 +195,11 @@ func (s *Server) GenerateHandler(c *gin.Context) {
 		return
 	}
 
-	useHarmony := shouldUseHarmony(m) && !req.Raw
+	useHarmony := harmony.ShouldUseHarmony(m.Config.ModelFamily, m.Template) && !req.Raw
-	var harmonyMessageHandler *harmony.HarmonyMessageHandler
+	var functionNameMap *harmony.FunctionNameMap
-	var harmonyToolParser *harmony.HarmonyToolCallAccumulator
+
 	if useHarmony {
-		harmonyMessageHandler = harmony.NewHarmonyMessageHandler()
+		functionNameMap = harmony.NewFunctionNameMap()
-		harmonyMessageHandler.HarmonyParser.AddImplicitStart()
-		harmonyToolParser = harmonyMessageHandler.CreateToolParser()
 	}
 
 	// Validate Think value: string values currently only allowed for gptoss models
@@ -357,16 +343,19 @@ func (s *Server) GenerateHandler(c *gin.Context) {
 		var sb strings.Builder
 		defer close(ch)
 		if err := r.Completion(c.Request.Context(), llm.CompletionRequest{
-			Prompt:  prompt,
+			Prompt:     prompt,
-			Images:  images,
+			Images:     images,
-			Format:  req.Format,
+			Format:     req.Format,
-			Options: opts,
+			Options:    opts,
+			UseHarmony: useHarmony,
 		}, func(cr llm.CompletionResponse) {
 			res := api.GenerateResponse{
 				Model:     req.Model,
 				CreatedAt: time.Now().UTC(),
 				Response:  cr.Content,
 				Done:      cr.Done,
+				Thinking:  cr.Thinking,
+				ToolCalls: cr.ToolCalls,
 				Metrics: api.Metrics{
 					PromptEvalCount:    cr.PromptEvalCount,
 					PromptEvalDuration: cr.PromptEvalDuration,
@@ -375,12 +364,22 @@ func (s *Server) GenerateHandler(c *gin.Context) {
 				},
 			}
 
+			if res.Done {
+				res.DoneReason = cr.DoneReason.String()
+				res.TotalDuration = time.Since(checkpointStart)
+				res.LoadDuration = checkpointLoaded.Sub(checkpointStart)
+			}
+
 			if useHarmony {
-				content, thinking, toolContent := harmonyMessageHandler.AddContent(cr.Content, harmonyToolParser)
+				for i, tool := range res.ToolCalls {
-				res.Response = content
+					res.ToolCalls[i].Function.Name = functionNameMap.OriginalFromConverted(tool.Function.Name)
-				res.Thinking = thinking
+				}
-				harmonyToolParser.Add(toolContent)
+				if res.Response != "" || res.Thinking != "" || len(res.ToolCalls) > 0 || res.Done {
-			} else if thinkingState != nil {
+					ch <- res
+				}
+				return
+			}
+			if thinkingState != nil {
 				thinking, content := thinkingState.AddContent(cr.Content)
 				res.Thinking = thinking
 				res.Response = content
@@ -391,30 +390,6 @@ func (s *Server) GenerateHandler(c *gin.Context) {
 			}
 
 			if cr.Done {
-				if useHarmony {
-					toolName, toolContent := harmonyToolParser.Drain()
-					if toolName != nil {
-						*toolName = strings.TrimPrefix(*toolName, "functions.")
-						var args api.ToolCallFunctionArguments
-						if err := json.Unmarshal([]byte(toolContent), &args); err != nil {
-							errStr := fmt.Sprintf("error parsing tool call: raw='%s', err=%s", toolContent, err.Error())
-							ch <- gin.H{"error": errStr}
-							return
-						}
-
-						res.ToolCalls = append(res.ToolCalls, api.ToolCall{
-							Function: api.ToolCallFunction{
-								Name:      *toolName,
-								Arguments: args,
-							},
-						})
-					}
-				}
-
-				res.DoneReason = cr.DoneReason.String()
-				res.TotalDuration = time.Since(checkpointStart)
-				res.LoadDuration = checkpointLoaded.Sub(checkpointStart)
-
 				if !req.Raw {
 					tokens, err := r.Tokenize(c.Request.Context(), prompt+sb.String())
 					if err != nil {
@@ -1616,27 +1591,36 @@ func (s *Server) ChatHandler(c *gin.Context) {
 	}
 	msgs = filterThinkTags(msgs, m)
 
-	var harmonyMessageHandler *harmony.HarmonyMessageHandler
+	useHarmony := harmony.ShouldUseHarmony(m.Config.ModelFamily, m.Template)
-	var harmonyToolParser *harmony.HarmonyToolCallAccumulator
-
-	useHarmony := shouldUseHarmony(m)
 
 	processedTools := req.Tools
+	var functionNameMap *harmony.FunctionNameMap
+	var prefillContentOrThinking *bool
 	if useHarmony {
-		harmonyMessageHandler = harmony.NewHarmonyMessageHandler()
+		functionNameMap = harmony.NewFunctionNameMap()
 		var lastMessage *api.Message
 		if len(msgs) > 0 {
 			lastMessage = &msgs[len(msgs)-1]
 		}
-		harmonyMessageHandler.HarmonyParser.AddImplicitStartOrPrefill(lastMessage)
-		harmonyToolParser = harmonyMessageHandler.CreateToolParser()
 
+		// prefill content or thinking flag if the last message is an assistant message
+		if lastMessage != nil && lastMessage.Role == "assistant" {
+			if lastMessage.Content != "" {
+				trueVal := true
+				// true sets content to be prefilled
+				prefillContentOrThinking = &trueVal
+			} else if lastMessage.Thinking != "" {
+				// false sets thinking to be prefilled
+				falseVal := false
+				prefillContentOrThinking = &falseVal
+			}
+		}
 		// make a copy of tools to pass to the chat prompt. Function names may be
 		// renamed to be valid Harmony function names.
 		processedTools = make([]api.Tool, len(req.Tools))
 		copy(processedTools, req.Tools)
 		for i, tool := range processedTools {
-			processedTools[i].Function.Name = harmonyMessageHandler.FunctionNameMap.ConvertAndAdd(tool.Function.Name)
+			processedTools[i].Function.Name = functionNameMap.ConvertAndAdd(tool.Function.Name)
 		}
 	}
 
@@ -1689,15 +1673,17 @@ func (s *Server) ChatHandler(c *gin.Context) {
 		defer close(ch)
 
 		if err := r.Completion(c.Request.Context(), llm.CompletionRequest{
-			Prompt:  prompt,
+			Prompt:         prompt,
-			Images:  images,
+			Images:         images,
-			Format:  req.Format,
+			Format:         req.Format,
-			Options: opts,
+			Options:        opts,
+			UseHarmony:     useHarmony,
+			PrefillContent: prefillContentOrThinking,
 		}, func(r llm.CompletionResponse) {
 			res := api.ChatResponse{
 				Model:     req.Model,
 				CreatedAt: time.Now().UTC(),
-				Message:   api.Message{Role: "assistant", Content: r.Content},
+				Message:   api.Message{Role: "assistant", Content: r.Content, Thinking: r.Thinking, ToolCalls: r.ToolCalls},
 				Done:      r.Done,
 				Metrics: api.Metrics{
 					PromptEvalCount:    r.PromptEvalCount,
@@ -1713,31 +1699,13 @@ func (s *Server) ChatHandler(c *gin.Context) {
 			}
 
 			if useHarmony {
-				content, thinking, toolContent := harmonyMessageHandler.AddContent(r.Content, harmonyToolParser)
-				res.Message.Content = content
-				res.Message.Thinking = thinking
-				harmonyToolParser.Add(toolContent)
-
-				if r.Done {
-					toolName, toolContent := harmonyToolParser.Drain()
-					if toolName != nil {
-						*toolName = strings.TrimPrefix(*toolName, "functions.")
-						*toolName = harmonyMessageHandler.FunctionNameMap.OriginalFromConverted(*toolName)
-						var args api.ToolCallFunctionArguments
-						if err := json.Unmarshal([]byte(toolContent), &args); err != nil {
-							errStr := fmt.Sprintf("error parsing tool call: raw='%s', err=%s", toolContent, err.Error())
-							ch <- gin.H{"error": errStr}
-							return
-						}
-						res.Message.ToolCalls = []api.ToolCall{{Function: api.ToolCallFunction{Name: *toolName, Arguments: args}}}
-					}
-				}
-
 				// only send messages with meaningful content (empty messages confuse clients)
+				for i, tool := range res.Message.ToolCalls {
+					res.Message.ToolCalls[i].Function.Name = functionNameMap.OriginalFromConverted(tool.Function.Name)
+				}
 				if res.Message.Content != "" || res.Message.Thinking != "" || len(res.Message.ToolCalls) > 0 || res.Done {
 					ch <- res
 				}
-
 				return
 			}
 

server/routes_harmony_streaming_test.go

@@ -7,7 +7,6 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
-	"net/http"
 	"strings"
 	"testing"
 	"time"
@@ -118,7 +117,7 @@ func TestChatHarmonyParserStreamingRealtime(t *testing.T) {
 			name: "content streams as it arrives",
 			steps: []step{
 				{
-					input:       llm.CompletionResponse{Content: "<|message|>Hello", Done: false},
+					input:       llm.CompletionResponse{Content: "Hello", Done: false},
 					wantContent: "Hello",
 				},
 				{
@@ -126,7 +125,7 @@ func TestChatHarmonyParserStreamingRealtime(t *testing.T) {
 					wantContent: ", world",
 				},
 				{
-					input:       llm.CompletionResponse{Content: "!<|end|>", Done: true, DoneReason: llm.DoneReasonStop},
+					input:       llm.CompletionResponse{Content: "!", Done: true, DoneReason: llm.DoneReasonStop},
 					wantContent: "!",
 				},
 			},
@@ -135,20 +134,15 @@ func TestChatHarmonyParserStreamingRealtime(t *testing.T) {
 			name: "thinking streams separately from content",
 			steps: []step{
 				{
-					input:        llm.CompletionResponse{Content: "<|channel|>analysis<|message|>Thinking...", Done: false},
+					input:        llm.CompletionResponse{Thinking: "Thinking...", Done: false},
 					wantThinking: "Thinking...",
 				},
 				{
-					input: llm.CompletionResponse{Content: "<|end|>", Done: false},
+					input:       llm.CompletionResponse{Content: "Answer", Done: false},
-					// No output expected - just closes the analysis message and resets state to normal
+					wantContent: "Answer",
 				},
 				{
-					input:       llm.CompletionResponse{Content: "<|start|>assistant<|message|>Answer", Done: false},
+					input: llm.CompletionResponse{Done: true, DoneReason: llm.DoneReasonStop},
-					wantContent: "Answer", // After message end, state is reset to normal
-				},
-				{
-					input: llm.CompletionResponse{Content: "<|end|>", Done: true, DoneReason: llm.DoneReasonStop},
-					// No output expected - just closes the assistant message
 				},
 			},
 		},
@@ -156,24 +150,16 @@ func TestChatHarmonyParserStreamingRealtime(t *testing.T) {
 			name: "partial tags buffer until complete",
 			steps: []step{
 				{
-					input: llm.CompletionResponse{Content: "<|chan", Done: false},
+					input:        llm.CompletionResponse{Thinking: "Deep ", Done: false},
-					// No output - partial tag
-				},
-				{
-					input: llm.CompletionResponse{Content: "nel|>analysis<|mess", Done: false},
-					// No output - still building tags
-				},
-				{
-					input:        llm.CompletionResponse{Content: "age|>Deep ", Done: false},
 					wantThinking: "Deep ",
 				},
 				{
-					input:        llm.CompletionResponse{Content: "thought<|end|>", Done: false},
+					input:        llm.CompletionResponse{Thinking: "thought", Done: false},
 					wantThinking: "thought",
 				},
 				{
-					input:       llm.CompletionResponse{Content: "<|start|>assistant<|message|>Done<|end|>", Done: true, DoneReason: llm.DoneReasonStop},
+					input:       llm.CompletionResponse{Content: "Done", Done: true, DoneReason: llm.DoneReasonStop},
-					wantContent: "Done", // After message end, state is reset to normal
+					wantContent: "Done",
 				},
 			},
 		},
@@ -181,7 +167,7 @@ func TestChatHarmonyParserStreamingRealtime(t *testing.T) {
 			name: "simple assistant after analysis",
 			steps: []step{
 				{
-					input:        llm.CompletionResponse{Content: "<|channel|>analysis<|message|>Think<|end|><|start|>assistant<|message|>Answer<|end|>", Done: true, DoneReason: llm.DoneReasonStop},
+					input:        llm.CompletionResponse{Thinking: "Think", Content: "Answer", Done: true, DoneReason: llm.DoneReasonStop},
 					wantContent:  "Answer",
 					wantThinking: "Think",
 				},
@@ -191,7 +177,7 @@ func TestChatHarmonyParserStreamingRealtime(t *testing.T) {
 			name: "tool call parsed and returned correctly",
 			steps: []step{
 				{
-					input:       llm.CompletionResponse{Content: "<|channel|>commentary to=functions.get_weather<|message|>{\"location\":\"San Francisco\"}<|end|><|start|>assistant<|message|>The weather is sunny<|end|>", Done: true, DoneReason: llm.DoneReasonStop},
+					input:       llm.CompletionResponse{Content: "The weather is sunny", ToolCalls: []api.ToolCall{{Function: api.ToolCallFunction{Name: "get_weather", Arguments: api.ToolCallFunctionArguments{"location": "San Francisco"}}}}, Done: true, DoneReason: llm.DoneReasonStop},
 					wantContent: "The weather is sunny",
 					wantToolCalls: []api.ToolCall{
 						{
@@ -210,15 +196,10 @@ func TestChatHarmonyParserStreamingRealtime(t *testing.T) {
 			name: "tool call with streaming JSON across chunks",
 			steps: []step{
 				{
-					input: llm.CompletionResponse{Content: "<|channel|>commentary to=functions.calculate<|message|>{\"expr", Done: false},
+					input: llm.CompletionResponse{Done: false},
-					// No output yet - incomplete JSON
 				},
 				{
-					input: llm.CompletionResponse{Content: "ession\":\"2+", Done: false},
+					input: llm.CompletionResponse{ToolCalls: []api.ToolCall{{Function: api.ToolCallFunction{Name: "calculate", Arguments: api.ToolCallFunctionArguments{"expression": "2+2"}}}}, Done: true},
-					// Still no output - incomplete JSON
-				},
-				{
-					input: llm.CompletionResponse{Content: "2\"}", Done: true},
 					wantToolCalls: []api.ToolCall{
 						{
 							Function: api.ToolCallFunction{
@@ -400,9 +381,9 @@ func TestChatHarmonyParserStreamingSimple(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 
 	mockResponses := []llm.CompletionResponse{
-		{Content: "<|message|>First ", Done: false},
+		{Content: "First ", Done: false},
 		{Content: "chunk ", Done: false},
-		{Content: "here<|end|>", Done: true, DoneReason: llm.DoneReasonStop},
+		{Content: "here", Done: true, DoneReason: llm.DoneReasonStop},
 	}
 
 	mock := mockRunner{
@@ -507,189 +488,3 @@ func TestChatHarmonyParserStreamingSimple(t *testing.T) {
 		t.Errorf("expected at least 2 content chunks for streaming, got %d", contentChunks)
 	}
 }
-
-func TestChatHarmonyParserStreaming(t *testing.T) {
-	gin.SetMode(gin.TestMode)
-
-	type expectedChunk struct {
-		afterResponse int    // Which mock response this chunk should appear after
-		content       string // Expected content in this chunk
-		thinking      string // Expected thinking in this chunk
-	}
-
-	testCases := []struct {
-		name           string
-		mockResponses  []llm.CompletionResponse
-		expectedChunks []expectedChunk
-		wantContent    string
-		wantThinking   string
-	}{
-		{
-			name: "simple message without thinking",
-			mockResponses: []llm.CompletionResponse{
-				{Content: "<|start|>assistant<|message|>Hello, ", Done: false},
-				{Content: "how can I help?", Done: false},
-				{Content: "<|end|>", Done: true, DoneReason: llm.DoneReasonStop},
-			},
-			expectedChunks: []expectedChunk{
-				{afterResponse: 1, content: "Hello, "},
-				{afterResponse: 2, content: "how can I help?"},
-			},
-			wantContent: "Hello, how can I help?",
-		},
-		{
-			name: "message with analysis channel for thinking",
-			mockResponses: []llm.CompletionResponse{
-				{Content: "<|channel|>analysis<|message|>", Done: false},
-				{Content: "Let me think ", Done: false},
-				{Content: "about this problem...", Done: false},
-				{Content: "<|end|>", Done: false},
-				{Content: "<|start|>assistant<|message|>", Done: false},
-				{Content: "The answer ", Done: false},
-				{Content: "is 42", Done: false},
-				{Content: "<|end|>", Done: true, DoneReason: llm.DoneReasonStop},
-			},
-			expectedChunks: []expectedChunk{
-				{afterResponse: 2, thinking: "Let me think "},
-				{afterResponse: 3, thinking: "about this problem..."},
-				{afterResponse: 6, content: "The answer "},
-				{afterResponse: 7, content: "is 42"},
-			},
-			wantContent:  "The answer is 42",
-			wantThinking: "Let me think about this problem...",
-		},
-		{
-			name: "streaming with partial tags across boundaries",
-			mockResponses: []llm.CompletionResponse{
-				{Content: "<|chan", Done: false},
-				{Content: "nel|>analy", Done: false},
-				{Content: "sis<|mess", Done: false},
-				{Content: "age|>Think", Done: false},
-				{Content: "ing deeply...<|end|>", Done: false},
-				{Content: "<|start|>assi", Done: false},
-				{Content: "stant<|message|>Result ", Done: false},
-				{Content: "computed<|e", Done: false},
-				{Content: "nd|>", Done: true, DoneReason: llm.DoneReasonStop},
-			},
-			expectedChunks: []expectedChunk{
-				{afterResponse: 4, thinking: "Think"},
-				{afterResponse: 5, thinking: "ing deeply..."},
-				{afterResponse: 7, content: "Result "},
-				{afterResponse: 8, content: "computed"},
-			},
-			wantContent:  "Result computed",
-			wantThinking: "Thinking deeply...",
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			// Channel to synchronize mock responses with chunk verification
-			responsesSent := make(chan int, len(tc.mockResponses))
-
-			mock := mockRunner{
-				CompletionFn: func(ctx context.Context, r llm.CompletionRequest, fn func(llm.CompletionResponse)) error {
-					// Send mock responses one at a time, notifying when each is sent
-					for i, resp := range tc.mockResponses {
-						fn(resp)
-						responsesSent <- i + 1
-					}
-					close(responsesSent)
-					return nil
-				},
-			}
-
-			s := Server{
-				sched: &Scheduler{
-					pendingReqCh:  make(chan *LlmRequest, 1),
-					finishedReqCh: make(chan *LlmRequest, 1),
-					expiredCh:     make(chan *runnerRef, 1),
-					unloadedCh:    make(chan any, 1),
-					loaded:        make(map[string]*runnerRef),
-					newServerFn:   newMockServer(&mock),
-					getGpuFn:      discover.GetGPUInfo,
-					getCpuFn:      discover.GetCPUInfo,
-					reschedDelay:  250 * time.Millisecond,
-					loadFn: func(req *LlmRequest, _ *ggml.GGML, _ discover.GpuInfoList, _ bool) bool {
-						req.successCh <- &runnerRef{
-							llama: &mock,
-						}
-						return false
-					},
-				},
-			}
-
-			go s.sched.Run(t.Context())
-
-			// Create a minimal model
-			_, digest := createHarmonyTestModel(t)
-
-			// Create model with passthrough template
-			stream := false
-			w := createRequest(t, s.CreateHandler, api.CreateRequest{
-				Model:    "harmony-test",
-				Files:    map[string]string{"file.gguf": digest},
-				Template: `<|start|><|end|>{{ with .Tools }}{{ end }}{{ .Prompt }}`,
-				Stream:   &stream,
-			})
-
-			if w.Code != http.StatusOK {
-				t.Fatalf("failed to create model: %d", w.Code)
-			}
-
-			// Test chat endpoint with streaming
-			streamTrue := true
-			w = createRequest(t, s.ChatHandler, api.ChatRequest{
-				Model:    "harmony-test",
-				Messages: []api.Message{{Role: "user", Content: "Hello"}},
-				Stream:   &streamTrue,
-				Tools:    getTestTools(),
-			})
-
-			if w.Code != http.StatusOK {
-				t.Fatalf("chat request failed: %d - %s", w.Code, w.Body.String())
-			}
-
-			// Parse streaming response
-			var chunks []api.ChatResponse
-			var content, thinking strings.Builder
-
-			decoder := json.NewDecoder(w.Body)
-			for decoder.More() {
-				var chunk api.ChatResponse
-				if err := decoder.Decode(&chunk); err != nil {
-					t.Fatalf("failed to decode chunk: %v", err)
-				}
-				chunks = append(chunks, chunk)
-
-				// Accumulate content and thinking from each chunk
-				content.WriteString(chunk.Message.Content)
-				thinking.WriteString(chunk.Message.Thinking)
-
-				// Debug output
-				t.Logf("Chunk %d: content=%q thinking=%q done=%v", len(chunks), chunk.Message.Content, chunk.Message.Thinking, chunk.Done)
-			}
-
-			// Verify we got streaming chunks
-			if len(chunks) == 0 {
-				t.Fatal("expected streaming chunks, got none")
-			}
-
-			gotContent := content.String()
-			gotThinking := thinking.String()
-
-			if gotContent != tc.wantContent {
-				t.Errorf("content mismatch: got %q, want %q", gotContent, tc.wantContent)
-			}
-			if gotThinking != tc.wantThinking {
-				t.Errorf("thinking mismatch: got %q, want %q", gotThinking, tc.wantThinking)
-			}
-
-			// Verify last chunk has done=true
-			lastChunk := chunks[len(chunks)-1]
-			if !lastChunk.Done {
-				t.Error("expected last chunk to have done=true")
-			}
-		})
-	}
-}