add qwen3-coder tool support

The format qwen3-coder uses is relatively unique, both in rendering and
in parsing. To implement parsing, I wrote a custom parser in similar
style to harmony. For the rendering, I found that the logic would be
much more difficult to follow in a template, so I introduced the concept
of a built-in renderer that uses go code, rather than a template to
generate prompts.

I set us up for future built-in parsers and renderers by making it so
they can be specified in a Modelfile like so:

```
RENDERER "qwen3-coder"
PARSER "qwen3-coder"
```

These need to be provided explicitly because the architecture alone is
not enough to understand what format the model expects to receive, and
what format we expect it to output (e.g., qwen3-coder is `qwen3moe`,
which includes other qwen3-family models as well)

I haven't converted harmony to be one of these "built-ins" yet, since
some of it is in flux with the changes @ParthSareen has been making to
move harmony to the runner. It is likely that many other built-ins will
need to move to the runner as well, but I'm able to slightly defer that
decision since qwen3-coder doesn't have thinking (and therefore doesn't
need to be in the runner to make structured outputs work). I expect to
unify harmony with this approach very soon.

Whether a particular model supports tools or thinking was previously
inferred from templates, but without a template we now also use the
parser itself to declare what it supports. If we have future models that
re-use the same parsing format, but have different capabilities, we'll
want to parameterize them and give them different names to be specified
as a `PARSER`.

Misc changes:

- I worked on the renderer by diffing outputs from the reference
  implementation and ours. To make it easier to do this, I extended
  <https://github.com/ollama/ollama/pull/11875> to also support
  returning the prompt via the openai compat layer

api/types.go

@@ -313,10 +313,11 @@ func (t *ToolFunction) String() string {
 // ChatResponse is the response returned by [Client.Chat]. Its fields are
 // similar to [GenerateResponse].
 type ChatResponse struct {
-	Model      string    `json:"model"`
-	CreatedAt  time.Time `json:"created_at"`
-	Message    Message   `json:"message"`
-	DoneReason string    `json:"done_reason,omitempty"`
+	Model      string     `json:"model"`
+	CreatedAt  time.Time  `json:"created_at"`
+	Message    Message    `json:"message"`
+	DoneReason string     `json:"done_reason,omitempty"`
+	DebugInfo  *DebugInfo `json:"_debug_info,omitempty"`
 
 	Done bool `json:"done"`
 
@@ -329,13 +330,6 @@ type DebugInfo struct {
 	ImageCount       int    `json:"image_count,omitempty"`
 }
 
-// DebugTemplateResponse is returned when _debug_render_only is set to true
-type DebugTemplateResponse struct {
-	Model     string    `json:"model"`
-	CreatedAt time.Time `json:"created_at"`
-	DebugInfo DebugInfo `json:"_debug_info"`
-}
-
 type Metrics struct {
 	TotalDuration      time.Duration `json:"total_duration,omitempty"`
 	LoadDuration       time.Duration `json:"load_duration,omitempty"`
@@ -443,6 +437,8 @@ type CreateRequest struct {
 	System     string            `json:"system,omitempty"`
 	Parameters map[string]any    `json:"parameters,omitempty"`
 	Messages   []Message         `json:"messages,omitempty"`
+	Renderer   string            `json:"renderer,omitempty"`
+	Parser     string            `json:"parser,omitempty"`
 
 	// Deprecated: set the model name with Model instead
 	Name string `json:"name"`
@@ -480,6 +476,8 @@ type ShowResponse struct {
 	Parameters    string             `json:"parameters,omitempty"`
 	Template      string             `json:"template,omitempty"`
 	System        string             `json:"system,omitempty"`
+	Renderer      string             `json:"renderer,omitempty"`
+	Parser        string             `json:"parser,omitempty"`
 	Details       ModelDetails       `json:"details,omitempty"`
 	Messages      []Message          `json:"messages,omitempty"`
 	ModelInfo     map[string]any     `json:"model_info,omitempty"`
@@ -592,6 +590,8 @@ type GenerateResponse struct {
 	Metrics
 
 	ToolCalls []ToolCall `json:"tool_calls,omitempty"`
+
+	DebugInfo *DebugInfo `json:"_debug_info,omitempty"`
 }
 
 // ModelDetails provides details about a model.

model/parsers/parsers.go

@@ -0,0 +1,37 @@
+package parsers
+
+import (
+	"github.com/ollama/ollama/api"
+)
+
+type BuiltinParser interface {
+	Add(s string, tools []api.Tool) (content string, thinking string, calls []api.ToolCall, err error)
+	HasToolSupport() bool
+	HasThinkingSupport() bool
+}
+
+func ParserForName(name string) BuiltinParser {
+	switch name {
+	case "qwen3-coder":
+		parser := &Qwen3CoderParser{}
+		return parser
+	case "passthrough":
+		return &PassthroughParser{}
+	default:
+		return nil
+	}
+}
+
+type PassthroughParser struct{}
+
+func (p *PassthroughParser) Add(s string, tools []api.Tool) (content string, thinking string, calls []api.ToolCall, err error) {
+	return s, "", nil, nil
+}
+
+func (p *PassthroughParser) HasToolSupport() bool {
+	return false
+}
+
+func (p *PassthroughParser) HasThinkingSupport() bool {
+	return false
+}

model/parsers/qwen3coder.go

@@ -0,0 +1,410 @@
+package parsers
+
+import (
+	"context"
+	"encoding/json"
+	"encoding/xml"
+	"fmt"
+	"log/slog"
+	"math"
+	"regexp"
+	"strconv"
+	"strings"
+	"unicode"
+
+	"github.com/ollama/ollama/api"
+	"github.com/ollama/ollama/logutil"
+)
+
+type qwenParserState int
+
+const (
+	toolOpenTag  = "<tool_call>"
+	toolCloseTag = "</tool_call>"
+)
+
+const (
+	qwenParserState_LookingForToolStart qwenParserState = iota
+	qwenParserState_CollectingToolContent
+)
+
+type Qwen3CoderParser struct {
+	state qwenParserState
+	acc   strings.Builder
+}
+
+func (p *Qwen3CoderParser) HasToolSupport() bool {
+	return true
+}
+
+func (p *Qwen3CoderParser) HasThinkingSupport() bool {
+	return false
+}
+
+func (p *Qwen3CoderParser) Add(s string, tools []api.Tool) (content string, thinking string, calls []api.ToolCall, err error) {
+	p.acc.WriteString(s)
+
+	events := p.parseEvents()
+
+	var toolCalls []api.ToolCall
+	var sb strings.Builder
+	for _, event := range events {
+		switch event := event.(type) {
+		case qwenEventRawToolCall:
+			toolCall, err := parseToolCall(event, tools)
+			if err != nil {
+				slog.Warn("qwen tool call parsing failed", "error", err)
+				return "", "", nil, err
+			}
+			toolCalls = append(toolCalls, toolCall)
+		case qwenEventContent:
+			// TODO(drifkin): if the same turn contains multiple interleaved content
+			// events, we naively append them together here. See the note below about
+			// `qwenEvent`s for more details
+			sb.WriteString(event.content)
+		}
+	}
+
+	return sb.String(), "", toolCalls, nil
+}
+
+func (p *Qwen3CoderParser) parseEvents() []qwenEvent {
+	var all []qwenEvent
+
+	keepLooping := true
+	for keepLooping {
+		var events []qwenEvent
+		events, keepLooping = eat(p)
+		if len(events) > 0 {
+			all = append(all, events...)
+		}
+	}
+
+	if len(all) > 0 {
+		slog.Log(context.TODO(), logutil.LevelTrace, "qwen events parsed", "events", all, "state", p.state, "acc", p.acc.String())
+	}
+
+	return all
+}
+
+// we use some internal event types in order to communicate between `Add` and
+// `eat`. We do this to support interleaving content and parallel tool calls in
+// the parser, even though qwen3-coder isn't supposed to do this. Our API
+// doesn't currently support models outputting multiple messages in a turn, so
+// we wouldn't be able to represent it yet, but there's no reason to prevent the
+// parser from supporting it, especially for future models if they end up using
+// a similar format.
+type qwenEvent interface {
+	isQwenEvent()
+}
+
+type qwenEventRawToolCall struct {
+	raw string
+}
+
+type qwenEventContent struct {
+	content string
+}
+
+func (qwenEventContent) isQwenEvent()     {}
+func (qwenEventRawToolCall) isQwenEvent() {}
+
+// eat consumes the parser's buffer, and returns a list of any unambiguous
+// events from the current parser state. If the parser transitions to another
+// state, it may have additional events to emit on the next call, which is what
+// the second return value indicates
+func eat(p *Qwen3CoderParser) ([]qwenEvent, bool) {
+	var events []qwenEvent
+
+	switch p.state {
+	case qwenParserState_LookingForToolStart:
+		if strings.Contains(p.acc.String(), toolOpenTag) {
+			// we found a full tool open tag, so we can emit the content before the
+			// tag, being sure to trim any trailing whitespace
+			split := strings.SplitN(p.acc.String(), toolOpenTag, 2)
+			before := split[0]
+			before = strings.TrimRightFunc(before, unicode.IsSpace)
+			if len(before) > 0 {
+				events = append(events, qwenEventContent{content: before})
+			}
+			after := split[1]
+			p.acc.Reset()
+			p.acc.WriteString(after)
+			p.state = qwenParserState_CollectingToolContent
+			return events, true
+		} else if overlap := overlap(p.acc.String(), toolOpenTag); overlap > 0 {
+			// we found a partial tool open tag, so we can emit the unambiguous part,
+			// which is the (trailing-whitespace trimmed) content before the partial
+			// tool open tag
+			beforePartialTag := p.acc.String()[:len(p.acc.String())-overlap]
+			trailingWhitespaceLen := trailingWhitespaceLen(beforePartialTag)
+			ambiguousStart := len(beforePartialTag) - trailingWhitespaceLen
+			unambiguous := p.acc.String()[:ambiguousStart]
+			ambiguous := p.acc.String()[ambiguousStart:]
+			p.acc.Reset()
+			p.acc.WriteString(ambiguous)
+			events = append(events, qwenEventContent{content: unambiguous})
+			return events, false
+		} else {
+			// we found content that is entirely not a tool call. We should withhold
+			// any trailing whitespace in case this is the end of the content
+			whitespaceLen := trailingWhitespaceLen(p.acc.String())
+			ambiguousStart := len(p.acc.String()) - whitespaceLen
+			unambiguous := p.acc.String()[:ambiguousStart]
+			ambiguous := p.acc.String()[ambiguousStart:]
+			p.acc.Reset()
+			p.acc.WriteString(ambiguous)
+			if len(unambiguous) > 0 {
+				events = append(events, qwenEventContent{content: unambiguous})
+			}
+			return events, false
+		}
+	case qwenParserState_CollectingToolContent:
+		if strings.Contains(p.acc.String(), toolCloseTag) {
+			split := strings.SplitN(p.acc.String(), toolCloseTag, 2)
+			before := split[0]
+			if len(before) == 0 {
+				slog.Warn("qwen tool call closing tag found but no content before it")
+			}
+			// remove any whitespace between the tool call and any content after it
+			after := strings.TrimLeftFunc(split[1], unicode.IsSpace)
+			p.acc.Reset()
+			p.acc.WriteString(after)
+			events = append(events, qwenEventRawToolCall{raw: before})
+			p.state = qwenParserState_LookingForToolStart
+			return events, true
+		} else {
+			// note that we don't need to check the overlap here because we only plan
+			// on parsing the tool call once we see the full closing tag. We don't
+			// stream back the unparsed tool content, so there's no need to be eager
+			// here
+			return events, false
+		}
+	default:
+		panic("unreachable")
+	}
+}
+
+// TODO(drifkin): move this to a shared location
+// longest overlap between suffix of s and prefix of delim
+func overlap(s, delim string) int {
+	max := min(len(delim), len(s))
+	for i := max; i > 0; i-- {
+		if strings.HasSuffix(s, delim[:i]) {
+			return i
+		}
+	}
+	return 0
+}
+
+func trailingWhitespaceLen(s string) int {
+	for i := len(s) - 1; i >= 0; i-- {
+		if !unicode.IsSpace(rune(s[i])) {
+			return len(s) - i - 1
+		}
+	}
+	return len(s)
+}
+
+type XMLFunctionCall struct {
+	XMLName    xml.Name       `xml:"function"`
+	Name       string         `xml:"name,attr"`
+	Parameters []XMLParameter `xml:"parameter"`
+}
+
+type XMLParameter struct {
+	Name  string `xml:"name,attr"`
+	Value string `xml:",chardata"`
+}
+
+// parseToolCall parses a raw tool call string into an api.ToolCall.
+// The raw string follows an xml-like format, here's an example:
+//
+// <function=get_current_temperature>
+// <parameter=location>
+// San Francisco
+// </parameter>
+// <parameter=unit>
+// celsius
+// </parameter>
+// </function>
+func parseToolCall(raw qwenEventRawToolCall, tools []api.Tool) (api.ToolCall, error) {
+	toolCall := api.ToolCall{}
+
+	xmlString := transformToXML(raw.raw)
+
+	var functionCall XMLFunctionCall
+	err := xml.Unmarshal([]byte(xmlString), &functionCall)
+	if err != nil {
+		return api.ToolCall{}, err
+	}
+
+	toolCall.Function = api.ToolCallFunction{
+		Name: functionCall.Name,
+	}
+
+	// Find the matching tool to get parameter types
+	var matchedTool *api.Tool
+	for i := range tools {
+		if tools[i].Function.Name == functionCall.Name {
+			matchedTool = &tools[i]
+			break
+		}
+	}
+
+	toolCall.Function.Arguments = make(api.ToolCallFunctionArguments)
+	for _, parameter := range functionCall.Parameters {
+		// Look up the parameter type if we found the tool
+		var paramType api.PropertyType
+		if matchedTool != nil && matchedTool.Function.Parameters.Properties != nil {
+			if prop, ok := matchedTool.Function.Parameters.Properties[parameter.Name]; ok {
+				paramType = prop.Type
+			}
+		}
+
+		toolCall.Function.Arguments[parameter.Name] = parseValue(parameter.Value, paramType)
+	}
+
+	return toolCall, nil
+}
+
+// parseValue converts a raw string value to the appropriate type based on the parameter type specification.
+//
+// For union types (multiple types in PropertyType, which we support but doesn't
+// seem as though the reference parser does type coercion with those types in
+// mind) we use a type precedence approach:
+// 1. null - checked first regardless of declared types (matches reference implementation)
+// 2. boolean - only "true"/"false" are valid booleans
+// 3. integer - must parse as a whole number
+// 4. number - must parse as numeric (returns int if no decimal part)
+// 5. array - must parse as valid JSON array
+// 6. object - must parse as valid JSON object
+// 7. string - always succeeds (least specific type)
+//
+// This precedence ensures we return the most specific type that successfully parses,
+// following the principle of least surprise. For example, with PropertyType{"string", "number"},
+// "123" becomes 123 (number), while "hello" becomes "hello" (string).
+func parseValue(raw string, paramType api.PropertyType) any {
+	// first remove a single leading newlines, and a single trailing newline (if
+	// they exist). This follows the reference implementation
+	raw = strings.TrimPrefix(raw, "\n")
+	raw = strings.TrimSuffix(raw, "\n")
+
+	// Check for null first (case-insensitive) - this takes precedence over any type
+	if strings.ToLower(raw) == "null" {
+		return nil
+	}
+
+	// If no type is specified, default to string
+	if len(paramType) == 0 {
+		return raw
+	}
+
+	// Check if any of the specified types match, using type precedence
+	// Order: boolean -> integer -> number -> array -> object -> string
+	typeSet := make(map[string]bool)
+	for _, t := range paramType {
+		typeSet[t] = true
+	}
+
+	// Try boolean first (most restrictive)
+	if typeSet["boolean"] {
+		lower := strings.ToLower(raw)
+		switch lower {
+		case "true":
+			return true
+		case "false":
+			return false
+		}
+		// If not a valid boolean but boolean is the only type, return false (matching reference)
+		if len(paramType) == 1 {
+			return false
+		}
+		// Otherwise try other types
+	}
+
+	// Try integer
+	if typeSet["integer"] {
+		if i, err := strconv.ParseInt(raw, 10, 64); err == nil {
+			// Return as int if it fits in int32, otherwise int64
+			if i >= math.MinInt32 && i <= math.MaxInt32 {
+				return int(i)
+			}
+			return i
+		}
+		// If integer is the only type and parsing failed, fall back to string
+		if len(paramType) == 1 {
+			return raw
+		}
+	}
+
+	// Try number (float)
+	if typeSet["number"] {
+		if f, err := strconv.ParseFloat(raw, 64); err == nil {
+			// If the number has no decimal part, return as int (matching reference)
+			if f == math.Trunc(f) {
+				i := int64(f)
+				if i >= math.MinInt32 && i <= math.MaxInt32 {
+					return int(i)
+				}
+				return i
+			}
+			return f
+		}
+		// If number is the only type and parsing failed, fall back to string
+		if len(paramType) == 1 {
+			return raw
+		}
+	}
+
+	// Try array
+	if typeSet["array"] {
+		var arr []interface{}
+		if err := json.Unmarshal([]byte(raw), &arr); err == nil {
+			return arr
+		}
+		// If array is the only type and parsing failed, fall back to string
+		if len(paramType) == 1 {
+			return raw
+		}
+	}
+
+	// Try object
+	if typeSet["object"] {
+		var obj map[string]interface{}
+		if err := json.Unmarshal([]byte(raw), &obj); err == nil {
+			return obj
+		}
+		// If object is the only type and parsing failed, fall back to string
+		if len(paramType) == 1 {
+			return raw
+		}
+	}
+
+	// String always succeeds (or if "string" is in the type set)
+	if typeSet["string"] {
+		return raw
+	}
+
+	// If we get here, none of the types matched and string wasn't an option
+	// We return string as a fallback. The reference implementation will attempt
+	// to parse the value as a python literal, but we purposefully don't support
+	// that
+	return raw
+}
+
+var qwenTagRegex = regexp.MustCompile(`<(\w+)=([^>]+)>`)
+
+// transformToXML transforms a raw qwen tool call with xml-like tags into valid
+// xml so that it can be parsed by any xml parser
+func transformToXML(raw string) string {
+	// take the form `<tag=abc>` and transform it to `<tag name="abc">`, taking
+	// care to properly escape the string that becomes the attribute value
+	return qwenTagRegex.ReplaceAllStringFunc(raw, func(match string) string {
+		groups := qwenTagRegex.FindStringSubmatch(match)
+		tag := groups[1]
+		var escapedValue strings.Builder
+		xml.EscapeText(&escapedValue, []byte(groups[2]))
+		return fmt.Sprintf(`<%s name="%s">`, tag, escapedValue.String())
+	})
+}

model/parsers/qwen3coder_test.go

@@ -0,0 +1,830 @@
+package parsers
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/ollama/ollama/api"
+)
+
+// tool creates a test tool with the given name and properties
+func tool(name string, props map[string]api.ToolProperty) api.Tool {
+	t := api.Tool{Type: "function", Function: api.ToolFunction{Name: name}}
+	t.Function.Parameters.Type = "object"
+	t.Function.Parameters.Properties = props
+	return t
+}
+
+func TestQwenParserStreaming(t *testing.T) {
+	type step struct {
+		input      string
+		wantEvents []qwenEvent
+	}
+
+	cases := []struct {
+		desc  string
+		steps []step
+		only  bool
+	}{
+		{
+			desc: "simple message streamed word by word",
+			steps: []step{
+				{
+					input:      "hi",
+					wantEvents: []qwenEvent{qwenEventContent{content: "hi"}},
+				},
+				{
+					input:      " there",
+					wantEvents: []qwenEvent{qwenEventContent{content: " there"}},
+				},
+			},
+		},
+		{
+			desc: "content before tool call",
+			steps: []step{
+				{
+					input:      "hi there<tool_call>",
+					wantEvents: []qwenEvent{qwenEventContent{content: "hi there"}},
+				},
+			},
+		},
+		{
+			desc: "multiple tool calls in one message",
+			steps: []step{
+				{
+					input: "before1<tool_call>in tool call</tool_call>after1<tool_call>in tool call 2</tool_call>after2",
+					wantEvents: []qwenEvent{
+						qwenEventContent{content: "before1"},
+						qwenEventRawToolCall{raw: "in tool call"},
+						qwenEventContent{content: "after1"},
+						qwenEventRawToolCall{raw: "in tool call 2"},
+						qwenEventContent{content: "after2"},
+					},
+				},
+			},
+		},
+		{
+			desc: "tool calls with split tags",
+			steps: []step{
+				{
+					input: "before<tool",
+					wantEvents: []qwenEvent{
+						qwenEventContent{content: "before"},
+					},
+				},
+				{
+					input:      "_call>in tool call</tool",
+					wantEvents: []qwenEvent{},
+				},
+				{
+					input: "_call>af",
+					wantEvents: []qwenEvent{
+						qwenEventRawToolCall{raw: "in tool call"},
+						qwenEventContent{content: "af"},
+					},
+				},
+				{
+					input: "ter",
+					wantEvents: []qwenEvent{
+						qwenEventContent{content: "ter"},
+					},
+				},
+			},
+		},
+		{
+			desc: "trailing whitespace between content and tool call",
+			steps: []step{
+				{
+					input: "abc\n<tool_call>def</tool_call>",
+					wantEvents: []qwenEvent{
+						qwenEventContent{content: "abc"},
+						qwenEventRawToolCall{raw: "def"},
+					},
+				},
+			},
+		},
+		{
+			desc: "trailing whitespace between tool call and content",
+			steps: []step{
+				{
+					input: "<tool_call>abc</tool_call>\ndef",
+					wantEvents: []qwenEvent{
+						qwenEventRawToolCall{raw: "abc"},
+						qwenEventContent{content: "def"},
+					},
+				},
+			},
+		},
+		{
+			desc: "empty content before tool call",
+			steps: []step{
+				{
+					input: "\n<tool_call>abc</tool_call>",
+					wantEvents: []qwenEvent{
+						qwenEventRawToolCall{raw: "abc"},
+					},
+				},
+			},
+		},
+		{
+			desc: "partial tool open tag fakeout",
+			steps: []step{
+				{
+					input: "abc\n<tool_call",
+					wantEvents: []qwenEvent{
+						// \n should not be emitted yet because `<tool_call` might be a tool
+						// open tag, in which case the whitespace should be trimmed
+						qwenEventContent{content: "abc"},
+					},
+				},
+				{
+					input: " fakeout",
+					wantEvents: []qwenEvent{
+						qwenEventContent{content: "\n<tool_call fakeout"},
+					},
+				},
+			},
+		},
+		{
+			desc: "token-by-token whitespace handling",
+			steps: []step{
+				{
+					input: "a",
+					wantEvents: []qwenEvent{
+						qwenEventContent{content: "a"},
+					},
+				},
+				{
+					input:      "\n",
+					wantEvents: []qwenEvent{},
+				},
+				{
+					input: "b",
+					wantEvents: []qwenEvent{
+						qwenEventContent{content: "\nb"},
+					},
+				},
+			},
+		},
+	}
+
+	anyOnlies := false
+	for _, tc := range cases {
+		if tc.only {
+			anyOnlies = true
+		}
+	}
+
+	for _, tc := range cases {
+		if anyOnlies && !tc.only {
+			continue
+		}
+
+		t.Run(tc.desc, func(t *testing.T) {
+			parser := Qwen3CoderParser{}
+
+			for i, step := range tc.steps {
+				parser.acc.WriteString(step.input)
+				gotEvents := parser.parseEvents()
+
+				if len(gotEvents) == 0 && len(step.wantEvents) == 0 {
+					// avoid deep equal on empty vs. nil slices
+					continue
+				}
+
+				if !reflect.DeepEqual(gotEvents, step.wantEvents) {
+					t.Errorf("step %d: input %q: got events %#v, want %#v", i, step.input, gotEvents, step.wantEvents)
+				}
+			}
+		})
+	}
+}
+
+func TestQwenToolParser(t *testing.T) {
+	type step struct {
+		name         string
+		rawToolCall  string
+		tools        []api.Tool
+		wantToolCall api.ToolCall
+	}
+
+	steps := []step{
+		{
+			name:  "simple tool call",
+			tools: []api.Tool{},
+			rawToolCall: `<function=get_current_temperature>
+<parameter=location>
+San Francisco
+</parameter>
+<parameter=unit>
+celsius
+</parameter>
+</function>`,
+			wantToolCall: api.ToolCall{
+				Function: api.ToolCallFunction{
+					Name: "get_current_temperature",
+					Arguments: map[string]any{
+						"location": "San Francisco",
+						"unit":     "celsius",
+					},
+				},
+			},
+		},
+		{
+			name:  "names with spaces",
+			tools: []api.Tool{},
+			rawToolCall: `<function=get current temperature>
+<parameter=location with spaces>
+San Francisco
+</parameter>
+<parameter=unit with spaces>
+celsius
+</parameter>
+</function>`,
+			wantToolCall: api.ToolCall{
+				Function: api.ToolCallFunction{
+					Name: "get current temperature",
+					Arguments: map[string]any{
+						"location with spaces": "San Francisco",
+						"unit with spaces":     "celsius",
+					},
+				},
+			},
+		},
+		// this mirrors the reference implementation's behavior, but unclear if it
+		// ever happens. If so, then we should probably remove them instead, this
+		// test is to just document the current behavior and test that we don't get
+		// xml errors
+		{
+			name:  "names with quotes",
+			tools: []api.Tool{},
+			rawToolCall: `<function="get current temperature">
+<parameter="location with spaces">
+San Francisco
+</parameter>
+<parameter="unit with spaces">
+"celsius"
+</parameter>
+</function>`,
+			wantToolCall: api.ToolCall{
+				Function: api.ToolCallFunction{
+					Name: "\"get current temperature\"",
+					Arguments: map[string]any{
+						"\"location with spaces\"": "San Francisco",
+						"\"unit with spaces\"":     "\"celsius\"",
+					},
+				},
+			},
+		},
+		{
+			name: "tool call with typed parameters",
+			tools: []api.Tool{
+				tool("calculate", map[string]api.ToolProperty{
+					"x":       {Type: api.PropertyType{"number"}},
+					"y":       {Type: api.PropertyType{"integer"}},
+					"enabled": {Type: api.PropertyType{"boolean"}},
+					"items":   {Type: api.PropertyType{"array"}},
+				}),
+			},
+			rawToolCall: `<function=calculate>
+<parameter=x>
+3.14
+</parameter>
+<parameter=y>
+42
+</parameter>
+<parameter=enabled>
+true
+</parameter>
+<parameter=items>
+["a", "b", "c"]
+</parameter>
+</function>`,
+			wantToolCall: api.ToolCall{
+				Function: api.ToolCallFunction{
+					Name: "calculate",
+					Arguments: map[string]any{
+						"x":       3.14,
+						"y":       42,
+						"enabled": true,
+						"items":   []interface{}{"a", "b", "c"},
+					},
+				},
+			},
+		},
+	}
+
+	for i, step := range steps {
+		gotToolCall, err := parseToolCall(qwenEventRawToolCall{raw: step.rawToolCall}, step.tools)
+		if err != nil {
+			t.Errorf("step %d (%s): %v", i, step.name, err)
+		}
+		if !reflect.DeepEqual(gotToolCall, step.wantToolCall) {
+			t.Errorf("step %d (%s): got tool call %#v, want %#v", i, step.name, gotToolCall, step.wantToolCall)
+		}
+	}
+}
+
+func TestQwenToolCallValueParsing(t *testing.T) {
+	cases := []struct {
+		desc      string
+		raw       string
+		paramType api.PropertyType
+		want      any
+	}{
+		{
+			desc:      "default string value (no type specified)",
+			paramType: api.PropertyType{},
+			raw:       "some-string",
+			want:      "some-string",
+		},
+		{
+			desc:      "trim a single leading and trailing newline",
+			paramType: api.PropertyType{},
+			raw:       "\nsome-string\n",
+			want:      "some-string",
+		},
+		{
+			desc:      "trim at most one leading and trailing newline",
+			paramType: api.PropertyType{},
+			raw:       "\n\nsome-string\n\n",
+			want:      "\nsome-string\n",
+		},
+		{
+			desc:      "newline really has to be the first character to be trimmed",
+			paramType: api.PropertyType{},
+			raw:       " \nsome-string\n ",
+			want:      " \nsome-string\n ",
+		},
+		{
+			desc:      "numeric type",
+			paramType: api.PropertyType{"number"},
+			raw:       "123",
+			want:      123,
+		},
+		// Integer parsing tests
+		{
+			desc:      "integer type",
+			paramType: api.PropertyType{"integer"},
+			raw:       "42",
+			want:      42,
+		},
+		{
+			desc:      "negative integer",
+			paramType: api.PropertyType{"integer"},
+			raw:       "-100",
+			want:      -100,
+		},
+		{
+			desc:      "zero integer",
+			paramType: api.PropertyType{"integer"},
+			raw:       "0",
+			want:      0,
+		},
+		{
+			desc:      "integer with leading zeros",
+			paramType: api.PropertyType{"integer"},
+			raw:       "007",
+			want:      7,
+		},
+		{
+			desc:      "large integer",
+			paramType: api.PropertyType{"integer"},
+			raw:       "2147483648", // Just beyond int32 max
+			want:      int64(2147483648),
+		},
+		// Float/number parsing tests
+		{
+			desc:      "float type",
+			paramType: api.PropertyType{"number"},
+			raw:       "3.14",
+			want:      3.14,
+		},
+		{
+			desc:      "negative float",
+			paramType: api.PropertyType{"number"},
+			raw:       "-273.15",
+			want:      -273.15,
+		},
+		{
+			desc:      "float without decimal part",
+			paramType: api.PropertyType{"number"},
+			raw:       "100.0",
+			want:      100,
+		},
+		{
+			desc:      "scientific notation positive",
+			paramType: api.PropertyType{"number"},
+			raw:       "1.23e5",
+			want:      123000, // Will be int since it has no decimal part
+		},
+		{
+			desc:      "scientific notation negative",
+			paramType: api.PropertyType{"number"},
+			raw:       "1.5e-3",
+			want:      0.0015,
+		},
+		{
+			desc:      "very small float",
+			paramType: api.PropertyType{"number"},
+			raw:       "0.00000001",
+			want:      0.00000001,
+		},
+		// String parsing tests
+		{
+			desc:      "explicit string type",
+			paramType: api.PropertyType{"string"},
+			raw:       "hello world",
+			want:      "hello world",
+		},
+		{
+			desc:      "string with special characters",
+			paramType: api.PropertyType{"string"},
+			raw:       "/usr/local/bin/test-file_v2.0.sh",
+			want:      "/usr/local/bin/test-file_v2.0.sh",
+		},
+		{
+			desc:      "string with quotes",
+			paramType: api.PropertyType{"string"},
+			raw:       `He said "hello" to me`,
+			want:      `He said "hello" to me`,
+		},
+		{
+			desc:      "multiline string",
+			paramType: api.PropertyType{"string"},
+			raw:       "line one\nline two\nline three",
+			want:      "line one\nline two\nline three",
+		},
+		{
+			desc:      "empty string",
+			paramType: api.PropertyType{"string"},
+			raw:       "",
+			want:      "",
+		},
+		{
+			desc:      "string that looks like a number",
+			paramType: api.PropertyType{"string"},
+			raw:       "12345",
+			want:      "12345",
+		},
+		// Boolean parsing tests
+		{
+			desc:      "boolean true",
+			paramType: api.PropertyType{"boolean"},
+			raw:       "true",
+			want:      true,
+		},
+		{
+			desc:      "boolean false",
+			paramType: api.PropertyType{"boolean"},
+			raw:       "false",
+			want:      false,
+		},
+		{
+			desc:      "boolean case insensitive true",
+			paramType: api.PropertyType{"boolean"},
+			raw:       "True",
+			want:      true,
+		},
+		{
+			desc:      "boolean case insensitive false",
+			paramType: api.PropertyType{"boolean"},
+			raw:       "FALSE",
+			want:      false,
+		},
+		// Null parsing tests
+		{
+			desc:      "null value lowercase",
+			paramType: api.PropertyType{"string"},
+			raw:       "null",
+			want:      nil,
+		},
+		{
+			desc:      "null value case insensitive",
+			paramType: api.PropertyType{"integer"},
+			raw:       "NULL",
+			want:      nil,
+		},
+		// Array parsing tests
+		{
+			desc:      "array of strings",
+			paramType: api.PropertyType{"array"},
+			raw:       `["foo", "bar", "baz"]`,
+			want:      []interface{}{"foo", "bar", "baz"},
+		},
+		{
+			desc:      "array of numbers",
+			paramType: api.PropertyType{"array"},
+			raw:       `[1, 2.5, 3]`,
+			want:      []interface{}{float64(1), 2.5, float64(3)},
+		},
+		{
+			desc:      "array of mixed types",
+			paramType: api.PropertyType{"array"},
+			raw:       `["string", 123, true, null]`,
+			want:      []interface{}{"string", float64(123), true, nil},
+		},
+		{
+			desc:      "empty array",
+			paramType: api.PropertyType{"array"},
+			raw:       `[]`,
+			want:      []interface{}{},
+		},
+		// Object parsing tests
+		{
+			desc:      "simple object",
+			paramType: api.PropertyType{"object"},
+			raw:       `{"key": "value", "number": 42}`,
+			want:      map[string]interface{}{"key": "value", "number": float64(42)},
+		},
+		{
+			desc:      "nested object",
+			paramType: api.PropertyType{"object"},
+			raw:       `{"outer": {"inner": "value"}}`,
+			want:      map[string]interface{}{"outer": map[string]interface{}{"inner": "value"}},
+		},
+		{
+			desc:      "empty object",
+			paramType: api.PropertyType{"object"},
+			raw:       `{}`,
+			want:      map[string]interface{}{},
+		},
+		// Error cases and fallback behavior
+		{
+			desc:      "invalid integer falls back to string",
+			paramType: api.PropertyType{"integer"},
+			raw:       "not-a-number",
+			want:      "not-a-number",
+		},
+		{
+			desc:      "invalid float falls back to string",
+			paramType: api.PropertyType{"number"},
+			raw:       "3.14.159",
+			want:      "3.14.159",
+		},
+		{
+			desc:      "invalid boolean falls back to false",
+			paramType: api.PropertyType{"boolean"},
+			raw:       "yes",
+			want:      false,
+		},
+		{
+			desc:      "invalid JSON array falls back to string",
+			paramType: api.PropertyType{"array"},
+			raw:       "[1, 2, unclosed",
+			want:      "[1, 2, unclosed",
+		},
+		{
+			desc:      "invalid JSON object falls back to string",
+			paramType: api.PropertyType{"object"},
+			raw:       `{"key": unclosed`,
+			want:      `{"key": unclosed`,
+		},
+		// Edge cases
+		{
+			desc:      "integer overflow should use int64",
+			paramType: api.PropertyType{"integer"},
+			raw:       "2147483648", // Beyond int32 max
+			want:      int64(2147483648),
+		},
+		{
+			desc:      "float with many decimal places",
+			paramType: api.PropertyType{"number"},
+			raw:       "3.141592653589793",
+			want:      3.141592653589793,
+		},
+		{
+			desc:      "string with JSON-like content",
+			paramType: api.PropertyType{"string"},
+			raw:       `{"this": "is", "just": "a string"}`,
+			want:      `{"this": "is", "just": "a string"}`,
+		},
+		{
+			desc:      "whitespace-only string",
+			paramType: api.PropertyType{"string"},
+			raw:       "   ",
+			want:      "   ",
+		},
+		// Unknown parameter (no type specified in tools)
+		{
+			desc:      "parameter not in tool definition defaults to string",
+			paramType: api.PropertyType{},
+			raw:       "some value",
+			want:      "some value",
+		},
+		// Union type tests
+		{
+			desc:      "string or number union - valid number",
+			paramType: api.PropertyType{"string", "number"},
+			raw:       "42.5",
+			want:      42.5,
+		},
+		{
+			desc:      "string or number union - non-numeric string",
+			paramType: api.PropertyType{"string", "number"},
+			raw:       "hello",
+			want:      "hello",
+		},
+		{
+			desc:      "number or string union - valid number (order shouldn't matter)",
+			paramType: api.PropertyType{"number", "string"},
+			raw:       "42.5",
+			want:      42.5,
+		},
+		{
+			desc:      "integer or null union - valid integer",
+			paramType: api.PropertyType{"integer", "null"},
+			raw:       "123",
+			want:      123,
+		},
+		{
+			desc:      "integer or null union - null value",
+			paramType: api.PropertyType{"integer", "null"},
+			raw:       "null",
+			want:      nil,
+		},
+		{
+			desc:      "null or integer union - null value (order shouldn't matter)",
+			paramType: api.PropertyType{"null", "integer"},
+			raw:       "null",
+			want:      nil,
+		},
+		{
+			desc:      "boolean or string union - valid boolean",
+			paramType: api.PropertyType{"boolean", "string"},
+			raw:       "true",
+			want:      true,
+		},
+		{
+			desc:      "boolean or string union - non-boolean becomes string",
+			paramType: api.PropertyType{"boolean", "string"},
+			raw:       "yes",
+			want:      "yes",
+		},
+		{
+			desc:      "string or boolean union - valid boolean (precedence test)",
+			paramType: api.PropertyType{"string", "boolean"},
+			raw:       "false",
+			want:      false, // Should be boolean, not string "false"
+		},
+		{
+			desc:      "integer or number union - integer value",
+			paramType: api.PropertyType{"integer", "number"},
+			raw:       "42",
+			want:      42,
+		},
+		{
+			desc:      "integer or number union - float value",
+			paramType: api.PropertyType{"integer", "number"},
+			raw:       "42.5",
+			want:      42.5,
+		},
+		{
+			desc:      "number or integer union - integer value (precedence test)",
+			paramType: api.PropertyType{"number", "integer"},
+			raw:       "42",
+			want:      42, // Should try integer first due to precedence
+		},
+		{
+			desc:      "array or object union - valid array",
+			paramType: api.PropertyType{"array", "object"},
+			raw:       `[1, 2, 3]`,
+			want:      []interface{}{float64(1), float64(2), float64(3)},
+		},
+		{
+			desc:      "array or object union - valid object",
+			paramType: api.PropertyType{"array", "object"},
+			raw:       `{"key": "value"}`,
+			want:      map[string]interface{}{"key": "value"},
+		},
+		{
+			desc:      "object or array union - valid array (precedence test)",
+			paramType: api.PropertyType{"object", "array"},
+			raw:       `[1, 2, 3]`,
+			want:      []interface{}{float64(1), float64(2), float64(3)},
+		},
+		{
+			desc:      "complex multi-type union - null",
+			paramType: api.PropertyType{"string", "number", "boolean", "null"},
+			raw:       "null",
+			want:      nil,
+		},
+		{
+			desc:      "complex multi-type union - boolean",
+			paramType: api.PropertyType{"string", "number", "boolean", "null"},
+			raw:       "true",
+			want:      true,
+		},
+		{
+			desc:      "complex multi-type union - number",
+			paramType: api.PropertyType{"string", "number", "boolean", "null"},
+			raw:       "3.14",
+			want:      3.14,
+		},
+		{
+			desc:      "complex multi-type union - string",
+			paramType: api.PropertyType{"string", "number", "boolean", "null"},
+			raw:       "hello",
+			want:      "hello",
+		},
+		{
+			desc:      "integer string union - integer string becomes integer",
+			paramType: api.PropertyType{"integer", "string"},
+			raw:       "123",
+			want:      123,
+		},
+		{
+			desc:      "string integer union - integer string becomes integer (precedence)",
+			paramType: api.PropertyType{"string", "integer"},
+			raw:       "123",
+			want:      123, // Integer has higher precedence than string
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.desc, func(t *testing.T) {
+			got := parseValue(tc.raw, tc.paramType)
+			if !reflect.DeepEqual(got, tc.want) {
+				t.Errorf("got %v (type %T), want %v (type %T)", got, got, tc.want, tc.want)
+			}
+		})
+	}
+}
+
+func TestQwenXMLTransform(t *testing.T) {
+	cases := []struct {
+		desc string
+		raw  string
+		want string
+	}{
+		{
+			desc: "simple example",
+			raw: `<function=get_current_temperature>
+<parameter=location>
+San Francisco
+</parameter>
+<parameter=unit>
+celsius
+</parameter>
+</function>`,
+			want: `<function name="get_current_temperature">
+<parameter name="location">
+San Francisco
+</parameter>
+<parameter name="unit">
+celsius
+</parameter>
+</function>`,
+		},
+		// even though quotes aren't expected in these tags, we have these tests to
+		// make sure they're escaped so they don't blow up the xml parser in case
+		// they happen
+		{
+			desc: "names with quotes",
+			raw: `<function="get current temperature">
+<parameter="location with spaces">
+San Francisco
+</parameter>
+<parameter="unit with spaces">
+celsius
+</parameter>
+</function>`,
+			want: `<function name="&#34;get current temperature&#34;">
+<parameter name="&#34;location with spaces&#34;">
+San Francisco
+</parameter>
+<parameter name="&#34;unit with spaces&#34;">
+celsius
+</parameter>
+</function>`,
+		},
+	}
+
+	for _, tc := range cases {
+		got := transformToXML(tc.raw)
+		if got != tc.want {
+			t.Errorf("got %q, want %q", got, tc.want)
+		}
+	}
+}
+
+func TestTrailingWhitespaceLen(t *testing.T) {
+	cases := []struct {
+		desc string
+		s    string
+		want int
+	}{
+		{desc: "no whitespace", s: "abc", want: 0},
+		{desc: "trailing whitespace", s: "abc ", want: 1},
+		{desc: "trailing whitespace with newlines", s: "abc \n", want: 2},
+		{desc: "only whitespace", s: " \n  ", want: 4},
+		{desc: "leading whitespace doesn't count", s: " \n abc", want: 0},
+	}
+
+	for _, tc := range cases {
+		got := trailingWhitespaceLen(tc.s)
+		if got != tc.want {
+			t.Errorf("got %d, want %d", got, tc.want)
+		}
+	}
+}

model/renderers/qwen3coder.go

@@ -0,0 +1,217 @@
+package renderers
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strings"
+
+	"github.com/ollama/ollama/api"
+)
+
+var (
+	imStartTag = "<|im_start|>"
+	imEndTag   = "<|im_end|>"
+)
+
+// renderAdditionalKeys renders all JSON fields except the ones in handledKeys
+// This follows the same approach from the reference implementation, which gives
+// a particular key ordering
+func renderAdditionalKeys(obj interface{}, handledKeys map[string]bool) string {
+	data, err := json.Marshal(obj)
+	if err != nil {
+		return ""
+	}
+
+	var m map[string]interface{}
+	if err := json.Unmarshal(data, &m); err != nil {
+		return ""
+	}
+
+	var sb strings.Builder
+	for key, value := range m {
+		if handledKeys[key] {
+			continue
+		}
+
+		// Check if value is a map or array (needs JSON serialization)
+		switch v := value.(type) {
+		case map[string]interface{}, []interface{}:
+			jsonBytes, _ := json.Marshal(v)
+			// TODO(drifkin): it would be nice to format the JSON here similarly to
+			// python's default json.dumps behavior (spaces after commas and colons).
+			// This would let us be byte-for-byte compatible with the reference
+			// implementation for most common inputs
+			jsonStr := string(jsonBytes)
+			sb.WriteString("\n<" + key + ">" + jsonStr + "</" + key + ">")
+		case nil:
+			continue
+		default:
+			// Simple types, convert to string
+			sb.WriteString("\n<" + key + ">" + fmt.Sprintf("%v", value) + "</" + key + ">")
+		}
+	}
+
+	return sb.String()
+}
+
+func Qwen3CoderRenderer(messages []api.Message, tools []api.Tool, _ *api.ThinkValue) (string, error) {
+	var sb strings.Builder
+
+	// filter out system messages and choose the first (if any) to win
+	var systemMessage string
+	var filteredMessages []api.Message
+	for _, message := range messages {
+		if message.Role != "system" {
+			filteredMessages = append(filteredMessages, message)
+			continue
+		}
+
+		if systemMessage == "" {
+			systemMessage = message.Content
+		}
+	}
+
+	if systemMessage != "" || len(tools) > 0 {
+		sb.WriteString(imStartTag + "system\n")
+
+		// if we have tools but no system message, match the reference implementation by providing a default system message
+		if systemMessage == "" {
+			systemMessage = "You are Qwen, a helpful AI assistant that can interact with a computer to solve tasks."
+		}
+
+		sb.WriteString(systemMessage)
+
+		if len(tools) > 0 {
+			sb.WriteString("\n\n# Tools\n\nYou have access to the following functions:\n\n")
+			sb.WriteString("<tools>")
+			for _, tool := range tools {
+				sb.WriteString("\n")
+				sb.WriteString("<function>\n")
+				sb.WriteString("<name>" + tool.Function.Name + "</name>")
+				if tool.Function.Description != "" {
+					sb.WriteString("\n<description>" + tool.Function.Description + "</description>")
+				}
+				sb.WriteString("\n<parameters>")
+
+				for name, prop := range tool.Function.Parameters.Properties {
+					sb.WriteString("\n<parameter>")
+					sb.WriteString("\n<name>" + name + "</name>")
+
+					if len(prop.Type) > 0 {
+						// TODO(!!!)(drifkin): we should match the reference implementation for
+						// more complex types here instead of using this format
+						sb.WriteString("\n<type>" + prop.ToTypeScriptType() + "</type>")
+					}
+
+					if prop.Description != "" {
+						sb.WriteString("\n<description>" + prop.Description + "</description>")
+					}
+
+					// Render any additional keys not already handled
+					handledKeys := map[string]bool{
+						"type":        true,
+						"description": true,
+					}
+					sb.WriteString(renderAdditionalKeys(prop, handledKeys))
+
+					sb.WriteString("\n</parameter>")
+				}
+
+				// Render extra keys for parameters (everything except 'type' and 'properties')
+				paramHandledKeys := map[string]bool{
+					"type":       true,
+					"properties": true,
+				}
+				sb.WriteString(renderAdditionalKeys(tool.Function.Parameters, paramHandledKeys))
+
+				sb.WriteString("\n</parameters>")
+				sb.WriteString("\n</function>")
+			}
+			sb.WriteString("\n</tools>")
+			sb.WriteString("\n\nIf 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>")
+		}
+
+		sb.WriteString(imEndTag + "\n")
+	}
+
+	for i, message := range filteredMessages {
+		lastMessage := i == len(filteredMessages)-1
+		prefill := lastMessage && message.Role == "assistant"
+		switch message.Role {
+		case "assistant":
+			if len(message.ToolCalls) > 0 {
+				sb.WriteString(imStartTag + "assistant\n")
+				if message.Content != "" {
+					sb.WriteString(message.Content + "\n")
+				}
+				for _, toolCall := range message.ToolCalls {
+					sb.WriteString("\n<tool_call>\n<function=" + toolCall.Function.Name + ">")
+					for name, value := range toolCall.Function.Arguments {
+						valueStr := formatToolCallArgument(value)
+						sb.WriteString("\n<parameter=" + name + ">\n" + valueStr + "\n</parameter>")
+					}
+					sb.WriteString("\n</function>\n</tool_call>")
+				}
+				sb.WriteString("<|im_end|>\n")
+			} else {
+				sb.WriteString(imStartTag + "assistant\n")
+				sb.WriteString(message.Content)
+				if !prefill {
+					sb.WriteString(imEndTag + "\n")
+				}
+			}
+		case "tool":
+			// consecutive tool responses should share a single `<im_start>user`, but
+			// have their own <tool_response> tags
+
+			// only start a new user block if this is the first tool response
+			if i == 0 || filteredMessages[i-1].Role != "tool" {
+				sb.WriteString(imStartTag + "user\n")
+			}
+
+			sb.WriteString("<tool_response>\n")
+			sb.WriteString(message.Content)
+			sb.WriteString("\n</tool_response>\n")
+
+			// close the user block only if this is the last tool response
+			if i == len(filteredMessages)-1 || filteredMessages[i+1].Role != "tool" {
+				sb.WriteString(imEndTag + "\n")
+			}
+		default:
+			sb.WriteString(imStartTag + message.Role + "\n")
+			sb.WriteString(message.Content)
+			sb.WriteString(imEndTag + "\n")
+		}
+
+		if lastMessage && !prefill {
+			sb.WriteString(imStartTag + "assistant\n")
+		}
+	}
+
+	return sb.String(), nil
+}
+
+func formatToolCallArgument(value any) string {
+	if value == nil {
+		return "null"
+	}
+
+	switch v := value.(type) {
+	case string:
+		return v
+	case []byte:
+		return string(v)
+	}
+
+	if reflect.TypeOf(value) != nil {
+		kind := reflect.TypeOf(value).Kind()
+		if kind == reflect.Map || kind == reflect.Slice || kind == reflect.Array {
+			if marshalled, err := json.Marshal(value); err == nil {
+				return string(marshalled)
+			}
+		}
+	}
+
+	return fmt.Sprintf("%v", value)
+}

model/renderers/qwen3coder_test.go

@@ -0,0 +1,338 @@
+package renderers
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/ollama/ollama/api"
+)
+
+func TestQwen3CoderRenderer(t *testing.T) {
+	tests := []struct {
+		name     string
+		msgs     []api.Message
+		tools    []api.Tool
+		expected string
+	}{
+		{
+			name: "basic",
+			msgs: []api.Message{
+				{Role: "system", Content: "You are a helpful assistant."},
+				{Role: "user", Content: "Hello, how are you?"},
+			},
+			expected: `<|im_start|>system
+You are a helpful assistant.<|im_end|>
+<|im_start|>user
+Hello, how are you?<|im_end|>
+<|im_start|>assistant
+`,
+		},
+		{
+			name: "with tools and response",
+			msgs: []api.Message{
+				{Role: "system", Content: "You are a helpful assistant with access to tools."},
+				{Role: "user", Content: "What is the weather like in San Francisco?"},
+				{
+					Role:    "assistant",
+					Content: "I'll check the weather in San Francisco for you.",
+					ToolCalls: []api.ToolCall{
+						{
+							Function: api.ToolCallFunction{
+								Name: "get_weather",
+								Arguments: map[string]any{
+									"unit": "fahrenheit",
+								},
+							},
+						},
+					},
+				},
+				{Role: "tool", Content: "{\"location\": \"San Francisco, CA\", \"temperature\": 68, \"condition\": \"partly cloudy\", \"humidity\": 65, \"wind_speed\": 12}", ToolName: "get_weather"},
+				{Role: "user", Content: "That sounds nice! What about New York?"},
+			},
+			tools: []api.Tool{
+				{Function: api.ToolFunction{
+					Name:        "get_weather",
+					Description: "Get the current weather in a given location",
+					Parameters: api.ToolFunctionParameters{
+						Required: []string{"unit"},
+						Properties: map[string]api.ToolProperty{
+							"unit": {Type: api.PropertyType{"string"}, Enum: []any{"celsius", "fahrenheit"}, Description: "The unit of temperature"},
+							// TODO(drifkin): add multiple params back once we have predictable
+							// order via some sort of ordered map type (see
+							// <https://github.com/ollama/ollama/issues/12244>)
+							/*
+								"location": {Type: api.PropertyType{"string"}, Description: "The city and state, e.g. San Francisco, CA"},
+							*/
+						},
+					},
+				}},
+			},
+			expected: `<|im_start|>system
+You are a helpful assistant with access to tools.
+
+# Tools
+
+You have access to the following functions:
+
+<tools>
+<function>
+<name>get_weather</name>
+<description>Get the current weather in a given location</description>
+<parameters>
+<parameter>
+<name>unit</name>
+<type>string</type>
+<description>The unit of temperature</description>
+<enum>["celsius","fahrenheit"]</enum>
+</parameter>
+<required>["unit"]</required>
+</parameters>
+</function>
+</tools>
+
+If you choose to call a function ONLY reply in the following format with NO suffix:
+
+<tool_call>
+<function=example_function_name>
+<parameter=example_parameter_1>
+value_1
+</parameter>
+<parameter=example_parameter_2>
+This is the value for the second parameter
+that can span
+multiple lines
+</parameter>
+</function>
+</tool_call>
+
+<IMPORTANT>
+Reminder:
+- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags
+- Required parameters MUST be specified
+- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after
+- 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
+</IMPORTANT><|im_end|>
+<|im_start|>user
+What is the weather like in San Francisco?<|im_end|>
+<|im_start|>assistant
+I'll check the weather in San Francisco for you.
+
+<tool_call>
+<function=get_weather>
+<parameter=unit>
+fahrenheit
+</parameter>
+</function>
+</tool_call><|im_end|>
+<|im_start|>user
+<tool_response>
+{"location": "San Francisco, CA", "temperature": 68, "condition": "partly cloudy", "humidity": 65, "wind_speed": 12}
+</tool_response>
+<|im_end|>
+<|im_start|>user
+That sounds nice! What about New York?<|im_end|>
+<|im_start|>assistant
+`,
+		},
+		{
+			name: "parallel tool calls",
+			msgs: []api.Message{
+				{Role: "system", Content: "You are a helpful assistant with access to tools."},
+				{Role: "user", Content: "call double(1) and triple(2)"},
+				{Role: "assistant", Content: "I'll call double(1) and triple(2) for you.", ToolCalls: []api.ToolCall{
+					{Function: api.ToolCallFunction{Name: "double", Arguments: map[string]any{"number": "1"}}},
+					{Function: api.ToolCallFunction{Name: "triple", Arguments: map[string]any{"number": "2"}}},
+				}},
+				{Role: "tool", Content: "{\"number\": 2}", ToolName: "double"},
+				{Role: "tool", Content: "{\"number\": 6}", ToolName: "triple"},
+			},
+			tools: []api.Tool{
+				{Function: api.ToolFunction{Name: "double", Description: "Double a number", Parameters: api.ToolFunctionParameters{Properties: map[string]api.ToolProperty{
+					"number": {Type: api.PropertyType{"string"}, Description: "The number to double"},
+				}}}},
+				{Function: api.ToolFunction{Name: "triple", Description: "Triple a number", Parameters: api.ToolFunctionParameters{Properties: map[string]api.ToolProperty{
+					"number": {Type: api.PropertyType{"string"}, Description: "The number to triple"},
+				}}}},
+			},
+			expected: `<|im_start|>system
+You are a helpful assistant with access to tools.
+
+# Tools
+
+You have access to the following functions:
+
+<tools>
+<function>
+<name>double</name>
+<description>Double a number</description>
+<parameters>
+<parameter>
+<name>number</name>
+<type>string</type>
+<description>The number to double</description>
+</parameter>
+</parameters>
+</function>
+<function>
+<name>triple</name>
+<description>Triple a number</description>
+<parameters>
+<parameter>
+<name>number</name>
+<type>string</type>
+<description>The number to triple</description>
+</parameter>
+</parameters>
+</function>
+</tools>
+
+If you choose to call a function ONLY reply in the following format with NO suffix:
+
+<tool_call>
+<function=example_function_name>
+<parameter=example_parameter_1>
+value_1
+</parameter>
+<parameter=example_parameter_2>
+This is the value for the second parameter
+that can span
+multiple lines
+</parameter>
+</function>
+</tool_call>
+
+<IMPORTANT>
+Reminder:
+- Function calls MUST follow the specified format: an inner <function=...></function> block must be nested within <tool_call></tool_call> XML tags
+- Required parameters MUST be specified
+- You may provide optional reasoning for your function call in natural language BEFORE the function call, but NOT after
+- 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
+</IMPORTANT><|im_end|>
+<|im_start|>user
+call double(1) and triple(2)<|im_end|>
+<|im_start|>assistant
+I'll call double(1) and triple(2) for you.
+
+<tool_call>
+<function=double>
+<parameter=number>
+1
+</parameter>
+</function>
+</tool_call>
+<tool_call>
+<function=triple>
+<parameter=number>
+2
+</parameter>
+</function>
+</tool_call><|im_end|>
+<|im_start|>user
+<tool_response>
+{"number": 2}
+</tool_response>
+<tool_response>
+{"number": 6}
+</tool_response>
+<|im_end|>
+<|im_start|>assistant
+`,
+		},
+		{
+			name: "prefill",
+			msgs: []api.Message{
+				{Role: "system", Content: "You are a helpful assistant."},
+				{Role: "user", Content: "Tell me something interesting."},
+				{Role: "assistant", Content: "I'll tell you something interesting about cats"},
+			},
+			expected: `<|im_start|>system
+You are a helpful assistant.<|im_end|>
+<|im_start|>user
+Tell me something interesting.<|im_end|>
+<|im_start|>assistant
+I'll tell you something interesting about cats`,
+		},
+		{
+			name: "complex tool call arguments should remain json encoded",
+			msgs: []api.Message{
+				{Role: "user", Content: "call tool"},
+				{Role: "assistant", ToolCalls: []api.ToolCall{
+					{Function: api.ToolCallFunction{
+						Name: "echo",
+						Arguments: map[string]any{
+							"payload": map[string]any{"foo": "bar"},
+						},
+					}},
+				}},
+				{Role: "tool", Content: "{\"payload\": {\"foo\": \"bar\"}}", ToolName: "echo"},
+			},
+			expected: `<|im_start|>user
+call tool<|im_end|>
+<|im_start|>assistant
+
+<tool_call>
+<function=echo>
+<parameter=payload>
+{"foo":"bar"}
+</parameter>
+</function>
+</tool_call><|im_end|>
+<|im_start|>user
+<tool_response>
+{"payload": {"foo": "bar"}}
+</tool_response>
+<|im_end|>
+<|im_start|>assistant
+`,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			rendered, err := Qwen3CoderRenderer(tt.msgs, tt.tools, nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if diff := cmp.Diff(rendered, tt.expected); diff != "" {
+				t.Errorf("mismatch (-got +want):\n%s", diff)
+			}
+		})
+	}
+}
+
+func TestFormatToolCallArgument(t *testing.T) {
+	tests := []struct {
+		name     string
+		arg      any
+		expected string
+	}{
+		{
+			name: "string",
+			arg:  "foo",
+			// notice no quotes around the string
+			expected: "foo",
+		},
+		{
+			name:     "map",
+			arg:      map[string]any{"foo": "bar"},
+			expected: "{\"foo\":\"bar\"}",
+		},
+		{
+			name:     "number",
+			arg:      1,
+			expected: "1",
+		},
+		{
+			name:     "boolean",
+			arg:      true,
+			expected: "true",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := formatToolCallArgument(tt.arg)
+			if got != tt.expected {
+				t.Errorf("formatToolCallArgument(%v) = %v, want %v", tt.arg, got, tt.expected)
+			}
+		})
+	}
+}

model/renderers/renderer.go

@@ -0,0 +1,26 @@
+package renderers
+
+import (
+	"fmt"
+
+	"github.com/ollama/ollama/api"
+)
+
+type rendererFunc func([]api.Message, []api.Tool, *api.ThinkValue) (string, error)
+
+func RenderWithRenderer(name string, msgs []api.Message, tools []api.Tool, think *api.ThinkValue) (string, error) {
+	renderer := rendererForName(name)
+	if renderer == nil {
+		return "", fmt.Errorf("unknown renderer %q", name)
+	}
+	return renderer(msgs, tools, think)
+}
+
+func rendererForName(name string) rendererFunc {
+	switch name {
+	case "qwen3-coder":
+		return Qwen3CoderRenderer
+	default:
+		return nil
+	}
+}

openai/openai.go

@@ -105,16 +105,18 @@ type ChatCompletionRequest struct {
 	Tools            []api.Tool      `json:"tools"`
 	Reasoning        *Reasoning      `json:"reasoning,omitempty"`
 	ReasoningEffort  *string         `json:"reasoning_effort,omitempty"`
+	DebugRenderOnly  bool            `json:"_debug_render_only"`
 }
 
 type ChatCompletion struct {
-	Id                string   `json:"id"`
-	Object            string   `json:"object"`
-	Created           int64    `json:"created"`
-	Model             string   `json:"model"`
-	SystemFingerprint string   `json:"system_fingerprint"`
-	Choices           []Choice `json:"choices"`
-	Usage             Usage    `json:"usage,omitempty"`
+	Id                string         `json:"id"`
+	Object            string         `json:"object"`
+	Created           int64          `json:"created"`
+	Model             string         `json:"model"`
+	SystemFingerprint string         `json:"system_fingerprint"`
+	Choices           []Choice       `json:"choices"`
+	Usage             Usage          `json:"usage,omitempty"`
+	DebugInfo         *api.DebugInfo `json:"_debug_info,omitempty"`
 }
 
 type ChatCompletionChunk struct {
@@ -141,6 +143,7 @@ type CompletionRequest struct {
 	Temperature      *float32       `json:"temperature"`
 	TopP             float32        `json:"top_p"`
 	Suffix           string         `json:"suffix"`
+	DebugRenderOnly  bool           `json:"_debug_render_only"`
 }
 
 type Completion struct {
@@ -273,8 +276,8 @@ func toChatCompletion(id string, r api.ChatResponse) ChatCompletion {
 				}
 				return nil
 			}(r.DoneReason),
-		}},
-		Usage: toUsage(r),
+		}}, Usage: toUsage(r),
+		DebugInfo: r.DebugInfo,
 	}
 }
 
@@ -568,13 +571,14 @@ func fromChatRequest(r ChatCompletionRequest) (*api.ChatRequest, error) {
 	}
 
 	return &api.ChatRequest{
-		Model:    r.Model,
-		Messages: messages,
-		Format:   format,
-		Options:  options,
-		Stream:   &r.Stream,
-		Tools:    r.Tools,
-		Think:    think,
+		Model:           r.Model,
+		Messages:        messages,
+		Format:          format,
+		Options:         options,
+		Stream:          &r.Stream,
+		Tools:           r.Tools,
+		Think:           think,
+		DebugRenderOnly: r.DebugRenderOnly,
 	}, nil
 }
 
@@ -648,11 +652,12 @@ func fromCompleteRequest(r CompletionRequest) (api.GenerateRequest, error) {
 	}
 
 	return api.GenerateRequest{
-		Model:   r.Model,
-		Prompt:  r.Prompt,
-		Options: options,
-		Stream:  &r.Stream,
-		Suffix:  r.Suffix,
+		Model:           r.Model,
+		Prompt:          r.Prompt,
+		Options:         options,
+		Stream:          &r.Stream,
+		Suffix:          r.Suffix,
+		DebugRenderOnly: r.DebugRenderOnly,
 	}, nil
 }
 

parser/parser.go

@@ -100,6 +100,10 @@ func (f Modelfile) CreateRequest(relativeDir string) (*api.CreateRequest, error)
 			req.System = c.Args
 		case "license":
 			licenses = append(licenses, c.Args)
+		case "renderer":
+			req.Renderer = c.Args
+		case "parser":
+			req.Parser = c.Args
 		case "message":
 			role, msg, _ := strings.Cut(c.Args, ": ")
 			messages = append(messages, api.Message{Role: role, Content: msg})
@@ -320,7 +324,7 @@ func (c Command) String() string {
 	switch c.Name {
 	case "model":
 		fmt.Fprintf(&sb, "FROM %s", c.Args)
-	case "license", "template", "system", "adapter":
+	case "license", "template", "system", "adapter", "renderer", "parser":
 		fmt.Fprintf(&sb, "%s %s", strings.ToUpper(c.Name), quote(c.Args))
 	case "message":
 		role, message, _ := strings.Cut(c.Args, ": ")
@@ -346,7 +350,7 @@ const (
 var (
 	errMissingFrom        = errors.New("no FROM line")
 	errInvalidMessageRole = errors.New("message role must be one of \"system\", \"user\", or \"assistant\"")
-	errInvalidCommand     = errors.New("command must be one of \"from\", \"license\", \"template\", \"system\", \"adapter\", \"parameter\", or \"message\"")
+	errInvalidCommand     = errors.New("command must be one of \"from\", \"license\", \"template\", \"system\", \"adapter\", \"renderer\", \"parser\", \"parameter\", or \"message\"")
 )
 
 type ParserError struct {
@@ -606,7 +610,7 @@ func isValidMessageRole(role string) bool {
 
 func isValidCommand(cmd string) bool {
 	switch strings.ToLower(cmd) {
-	case "from", "license", "template", "system", "adapter", "parameter", "message":
+	case "from", "license", "template", "system", "adapter", "renderer", "parser", "parameter", "message":
 		return true
 	default:
 		return false

parser/parser_test.go

@@ -198,6 +198,34 @@ BADCOMMAND param1 value1
 	}
 }
 
+func TestParseFileRenderer(t *testing.T) {
+	input := `
+FROM foo
+RENDERER renderer1
+`
+
+	reader := strings.NewReader(input)
+
+	modelfile, err := ParseFile(reader)
+	require.NoError(t, err)
+
+	assert.Equal(t, []Command{{Name: "model", Args: "foo"}, {Name: "renderer", Args: "renderer1"}}, modelfile.Commands)
+}
+
+func TestParseFileParser(t *testing.T) {
+	input := `
+FROM foo
+PARSER parser1
+`
+
+	reader := strings.NewReader(input)
+
+	modelfile, err := ParseFile(reader)
+	require.NoError(t, err)
+
+	assert.Equal(t, []Command{{Name: "model", Args: "foo"}, {Name: "parser", Args: "parser1"}}, modelfile.Commands)
+}
+
 func TestParseFileMessages(t *testing.T) {
 	cases := []struct {
 		input    string

server/create.go

@@ -323,6 +323,8 @@ func createModel(r api.CreateRequest, name model.Name, baseLayers []*layerGGML,
 		RootFS: RootFS{
 			Type: "layers",
 		},
+		Renderer: r.Renderer,
+		Parser:   r.Parser,
 	}
 
 	var layers []Layer

server/images.go

@@ -24,6 +24,7 @@ import (
 	"github.com/ollama/ollama/api"
 	"github.com/ollama/ollama/envconfig"
 	"github.com/ollama/ollama/fs/gguf"
+	"github.com/ollama/ollama/model/parsers"
 	"github.com/ollama/ollama/parser"
 	"github.com/ollama/ollama/template"
 	"github.com/ollama/ollama/thinking"
@@ -94,8 +95,9 @@ func (m *Model) Capabilities() []model.Capability {
 		return capabilities
 	}
 
+	builtinParser := parsers.ParserForName(m.Config.Parser)
 	// Check for tools capability
-	if slices.Contains(m.Template.Vars(), "tools") {
+	if slices.Contains(m.Template.Vars(), "tools") || (builtinParser != nil && builtinParser.HasToolSupport()) {
 		capabilities = append(capabilities, model.CapabilityTools)
 	}
 
@@ -112,7 +114,8 @@ func (m *Model) Capabilities() []model.Capability {
 	// Check for thinking capability
 	openingTag, closingTag := thinking.InferTags(m.Template.Template)
 	hasTags := openingTag != "" && closingTag != ""
-	if hasTags || slices.Contains([]string{"gptoss", "gpt-oss"}, m.Config.ModelFamily) {
+	isGptoss := slices.Contains([]string{"gptoss", "gpt-oss"}, m.Config.ModelFamily)
+	if hasTags || isGptoss || (builtinParser != nil && builtinParser.HasThinkingSupport()) {
 		capabilities = append(capabilities, model.CapabilityThinking)
 	}
 
@@ -198,6 +201,20 @@ func (m *Model) String() string {
 		})
 	}
 
+	if m.Config.Renderer != "" {
+		modelfile.Commands = append(modelfile.Commands, parser.Command{
+			Name: "renderer",
+			Args: m.Config.Renderer,
+		})
+	}
+
+	if m.Config.Parser != "" {
+		modelfile.Commands = append(modelfile.Commands, parser.Command{
+			Name: "parser",
+			Args: m.Config.Parser,
+		})
+	}
+
 	for k, v := range m.Options {
 		switch v := v.(type) {
 		case []any:
@@ -238,6 +255,8 @@ type ConfigV2 struct {
 	ModelFamilies []string `json:"model_families"`
 	ModelType     string   `json:"model_type"`
 	FileType      string   `json:"file_type"`
+	Renderer      string   `json:"renderer,omitempty"`
+	Parser        string   `json:"parser,omitempty"`
 
 	// required by spec
 	Architecture string `json:"architecture"`

server/prompt.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/ollama/ollama/api"
 	"github.com/ollama/ollama/llm"
+	"github.com/ollama/ollama/model/renderers"
 	"github.com/ollama/ollama/template"
 )
 
@@ -41,18 +42,12 @@ func chatPrompt(ctx context.Context, m *Model, tokenize tokenizeFunc, opts *api.
 			}
 		}
 
-		thinkVal := false
-		thinkLevel := ""
-		if think != nil {
-			thinkVal = think.Bool()
-			thinkLevel = think.String()
-		}
-		var b bytes.Buffer
-		if err := m.Template.Execute(&b, template.Values{Messages: append(system, msgs[i:]...), Tools: tools, Think: thinkVal, ThinkLevel: thinkLevel, IsThinkSet: think != nil}); err != nil {
+		p, err := renderPrompt(m, append(system, msgs[i:]...), tools, think)
+		if err != nil {
 			return "", nil, err
 		}
 
-		s, err := tokenize(ctx, b.String())
+		s, err := tokenize(ctx, p)
 		if err != nil {
 			return "", nil, err
 		}
@@ -101,6 +96,23 @@ func chatPrompt(ctx context.Context, m *Model, tokenize tokenizeFunc, opts *api.
 	}
 
 	// truncate any messages that do not fit into the context window
+	p, err := renderPrompt(m, append(system, msgs[currMsgIdx:]...), tools, think)
+	if err != nil {
+		return "", nil, err
+	}
+
+	return p, images, nil
+}
+
+func renderPrompt(m *Model, msgs []api.Message, tools []api.Tool, think *api.ThinkValue) (string, error) {
+	if m.Config.Renderer != "" {
+		rendered, err := renderers.RenderWithRenderer(m.Config.Renderer, msgs, tools, think)
+		if err != nil {
+			return "", err
+		}
+		return rendered, nil
+	}
+
 	var b bytes.Buffer
 	thinkVal := false
 	thinkLevel := ""
@@ -108,9 +120,8 @@ func chatPrompt(ctx context.Context, m *Model, tokenize tokenizeFunc, opts *api.
 		thinkVal = think.Bool()
 		thinkLevel = think.String()
 	}
-	if err := m.Template.Execute(&b, template.Values{Messages: append(system, msgs[currMsgIdx:]...), Tools: tools, Think: thinkVal, ThinkLevel: thinkLevel, IsThinkSet: think != nil}); err != nil {
-		return "", nil, err
+	if err := m.Template.Execute(&b, template.Values{Messages: msgs, Tools: tools, Think: thinkVal, ThinkLevel: thinkLevel, IsThinkSet: think != nil}); err != nil {
+		return "", err
 	}
-
-	return b.String(), images, nil
+	return b.String(), nil
 }

server/routes.go

@@ -35,6 +35,7 @@ import (
 	"github.com/ollama/ollama/harmony"
 	"github.com/ollama/ollama/llm"
 	"github.com/ollama/ollama/logutil"
+	"github.com/ollama/ollama/model/parsers"
 	"github.com/ollama/ollama/openai"
 	"github.com/ollama/ollama/server/internal/client/ollama"
 	"github.com/ollama/ollama/server/internal/registry"
@@ -329,10 +330,10 @@ func (s *Server) GenerateHandler(c *gin.Context) {
 
 	// If debug mode is enabled, return the rendered template instead of calling the model
 	if req.DebugRenderOnly {
-		c.JSON(http.StatusOK, api.DebugTemplateResponse{
+		c.JSON(http.StatusOK, api.GenerateResponse{
 			Model:     req.Model,
 			CreatedAt: time.Now().UTC(),
-			DebugInfo: api.DebugInfo{
+			DebugInfo: &api.DebugInfo{
 				RenderedTemplate: prompt,
 				ImageCount:       len(images),
 			},
@@ -1617,10 +1618,15 @@ func (s *Server) ChatHandler(c *gin.Context) {
 	}
 	msgs = filterThinkTags(msgs, m)
 
+	var builtinParser parsers.BuiltinParser
+	if m.Config.Parser != "" {
+		builtinParser = parsers.ParserForName(m.Config.Parser)
+	}
+
 	var harmonyMessageHandler *harmony.HarmonyMessageHandler
 	var harmonyToolParser *harmony.HarmonyToolCallAccumulator
 
-	useHarmony := shouldUseHarmony(m)
+	useHarmony := shouldUseHarmony(m) || m.Config.Parser == "harmony"
 
 	processedTools := req.Tools
 	if useHarmony {
@@ -1650,10 +1656,10 @@ func (s *Server) ChatHandler(c *gin.Context) {
 
 	// If debug mode is enabled, return the rendered template instead of calling the model
 	if req.DebugRenderOnly {
-		c.JSON(http.StatusOK, api.DebugTemplateResponse{
+		c.JSON(http.StatusOK, api.ChatResponse{
 			Model:     req.Model,
 			CreatedAt: time.Now().UTC(),
-			DebugInfo: api.DebugInfo{
+			DebugInfo: &api.DebugInfo{
 				RenderedTemplate: prompt,
 				ImageCount:       len(images),
 			},
@@ -1713,6 +1719,7 @@ func (s *Server) ChatHandler(c *gin.Context) {
 				res.LoadDuration = checkpointLoaded.Sub(checkpointStart)
 			}
 
+			// TODO(drifkin): fold this as much as possibleinto the generic m.Config.Parser logic
 			if useHarmony {
 				content, thinking, toolContent := harmonyMessageHandler.AddContent(r.Content, harmonyToolParser)
 				res.Message.Content = content
@@ -1739,6 +1746,27 @@ func (s *Server) ChatHandler(c *gin.Context) {
 					ch <- res
 				}
 
+				return
+			} else if builtinParser != nil {
+				slog.Log(context.TODO(), logutil.LevelTrace, "builtin parser input", "parser", m.Config.Parser, "content", r.Content)
+
+				content, thinking, toolCalls, err := builtinParser.Add(r.Content, req.Tools)
+				if err != nil {
+					ch <- gin.H{"error": err.Error()}
+					return
+				}
+
+				res.Message.Content = content
+				res.Message.Thinking = thinking
+				res.Message.ToolCalls = toolCalls
+
+				if res.Message.Content != "" || res.Message.Thinking != "" || len(res.Message.ToolCalls) > 0 || r.Done {
+					slog.Log(context.TODO(), logutil.LevelTrace, "builtin parser output", "parser", m.Config.Parser, "content", content, "thinking", thinking, "toolCalls", toolCalls, "done", r.Done)
+					ch <- res
+				} else {
+					slog.Log(context.TODO(), logutil.LevelTrace, "builtin parser empty output", "parser", m.Config.Parser)
+				}
+
 				return
 			}
 

server/routes_debug_test.go

@@ -180,7 +180,7 @@ func TestGenerateDebugRenderOnly(t *testing.T) {
 						t.Errorf("expected status %d, got %d, body: %s", http.StatusOK, w.Code, w.Body.String())
 					}
 
-					var response api.DebugTemplateResponse
+					var response api.GenerateResponse
 					if err := json.Unmarshal(w.Body.Bytes(), &response); err != nil {
 						t.Fatalf("failed to unmarshal response: %v", err)
 					}
@@ -385,7 +385,7 @@ func TestChatDebugRenderOnly(t *testing.T) {
 						t.Errorf("expected status %d, got %d, body: %s", http.StatusOK, w.Code, w.Body.String())
 					}
 
-					var response api.DebugTemplateResponse
+					var response api.ChatResponse
 					if err := json.Unmarshal(w.Body.Bytes(), &response); err != nil {
 						t.Fatalf("failed to unmarshal response: %v", err)
 					}