mlx: Gemma4 MTP speculative decoding (#15980)

This change adds support for MTP (multi-token prediction) speculative decoding for the
gemma4 model family.

It includes:
  * support for importing safetensors based gemma4 draft models with `ollama create`
  * a new DRAFT command in the Modelfile for specifying draft models
  * a --quantize-draft flag for the ollama create command to quantize the draft model
  * cache support for speculation
  * changes to the rotating cache to be able to handle MTP correctly
  * sampling support for draft model token prediction

---------

Co-authored-by: Daniel Hiltgen <daniel@ollama.com>

.github/workflows/release.yaml

@@ -423,8 +423,8 @@ jobs:
               lib/ollama/*.so*)          echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}.tar.in ;;
               lib/ollama/cuda_v*)        echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}.tar.in ;;
               lib/ollama/vulkan*)        echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}.tar.in ;;
-              lib/ollama/mlx*)           echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}.tar.in ;;
+              lib/ollama/mlx*)           echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}-mlx.tar.in ;;
-              lib/ollama/include*)       echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}.tar.in ;;
+              lib/ollama/include*)       echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}-mlx.tar.in ;;
               lib/ollama/cuda_jetpack5)  echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}-jetpack5.tar.in ;;
               lib/ollama/cuda_jetpack6)  echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}-jetpack6.tar.in ;;
               lib/ollama/rocm)           echo $COMPONENT >>ollama-${{ matrix.os }}-${{ matrix.arch }}-rocm.tar.in ;;
@@ -458,12 +458,14 @@ jobs:
               CGO_CFLAGS
               CGO_CXXFLAGS
               GOFLAGS
+              APT_MIRROR=http://azure.archive.ubuntu.com/ubuntu
           - os: linux
             arch: amd64
             build-args: |
               CGO_CFLAGS
               CGO_CXXFLAGS
               GOFLAGS
+              APT_MIRROR=http://azure.archive.ubuntu.com/ubuntu
           - os: linux
             arch: amd64
             suffix: '-rocm'
@@ -472,6 +474,7 @@ jobs:
               CGO_CXXFLAGS
               GOFLAGS
               FLAVOR=rocm
+              APT_MIRROR=http://azure.archive.ubuntu.com/ubuntu
     runs-on: ${{ matrix.arch == 'arm64' && format('{0}-{1}', matrix.os, matrix.arch) || matrix.os }}
     environment: release
     needs: setup-environment

CMakePresets.json

@@ -41,7 +41,7 @@
       "inherits": [ "CUDA" ],
       "cacheVariables": {
         "CMAKE_CUDA_ARCHITECTURES": "75-virtual;80-virtual;86-virtual;87-virtual;89-virtual;90-virtual;90a-virtual;100-virtual;103-virtual;110-virtual;120-virtual;121-virtual",
-        "CMAKE_CUDA_FLAGS": "-t 4",
+        "CMAKE_CUDA_FLAGS": "-t 2",
         "OLLAMA_RUNNER_DIR": "cuda_v13"
       }
     },

Dockerfile

@@ -212,8 +212,11 @@ COPY --from=cpu dist/lib/ollama /lib/ollama
 COPY --from=build /bin/ollama /bin/ollama
 
 FROM ubuntu:24.04
-RUN apt-get update \
+ARG APT_MIRROR=http://archive.ubuntu.com/ubuntu
+RUN sed -i "s|http://archive.ubuntu.com/ubuntu|$APT_MIRROR|g" /etc/apt/sources.list.d/ubuntu.sources \
+    && apt-get update \
     && apt-get install -y ca-certificates libvulkan1 libopenblas0 \
+    && sed -i "s|$APT_MIRROR|http://archive.ubuntu.com/ubuntu|g" /etc/apt/sources.list.d/ubuntu.sources \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*
 COPY --from=archive /bin /usr/bin

cmd/cmd.go

@@ -54,6 +54,7 @@ import (
 	"github.com/ollama/ollama/types/syncmap"
 	"github.com/ollama/ollama/version"
 	xcmd "github.com/ollama/ollama/x/cmd"
+	xcreate "github.com/ollama/ollama/x/create"
 	xcreateclient "github.com/ollama/ollama/x/create/client"
 	"github.com/ollama/ollama/x/imagegen"
 )
@@ -145,6 +146,39 @@ func isLocalhost() bool {
 	return ip != nil && (ip.IsLoopback() || ip.IsUnspecified())
 }
 
+func resolveExperimentalLocalModelDir(ref, filename string) string {
+	if ref == "" || filepath.IsAbs(ref) || filename == "" {
+		return ref
+	}
+
+	candidate := filepath.Join(filepath.Dir(filename), ref)
+	if xcreate.IsSafetensorsModelDir(candidate) || xcreate.IsTensorModelDir(candidate) {
+		return candidate
+	}
+
+	return ref
+}
+
+func resolveExperimentalDraftDir(ref, filename string) (string, error) {
+	if ref == "" {
+		return "", nil
+	}
+	if filepath.IsAbs(ref) {
+		if xcreate.IsSafetensorsModelDir(ref) {
+			return ref, nil
+		}
+		return "", fmt.Errorf("draft %s is not a supported safetensors model directory", ref)
+	}
+	if filename != "" {
+		candidate := filepath.Join(filepath.Dir(filename), ref)
+		if xcreate.IsSafetensorsModelDir(candidate) {
+			return candidate, nil
+		}
+	}
+
+	return "", fmt.Errorf("DRAFT model references are not supported with --experimental yet: %s", ref)
+}
+
 func CreateHandler(cmd *cobra.Command, args []string) error {
 	p := progress.NewProgress(os.Stderr)
 	defer p.Stop()
@@ -159,6 +193,10 @@ func CreateHandler(cmd *cobra.Command, args []string) error {
 	// Check for --experimental flag for safetensors model creation
 	// This gates both safetensors LLM and imagegen model creation
 	experimental, _ := cmd.Flags().GetBool("experimental")
+	draftQuantize, _ := cmd.Flags().GetString("draft-quantize")
+	if draftQuantize != "" && !experimental {
+		return errors.New("--draft-quantize requires --experimental")
+	}
 	if experimental {
 		if !isLocalhost() {
 			return errors.New("remote safetensor model creation not yet supported")
@@ -192,17 +230,22 @@ func CreateHandler(cmd *cobra.Command, args []string) error {
 			return err
 		}
 
-		// Resolve relative paths based on Modelfile location
+		modelDir = resolveExperimentalLocalModelDir(modelDir, filename)
-		if !filepath.IsAbs(modelDir) && filename != "" {
+		if mfConfig.Draft != "" {
-			modelDir = filepath.Join(filepath.Dir(filename), modelDir)
+			draftDir, err := resolveExperimentalDraftDir(mfConfig.Draft, filename)
+			if err != nil {
+				return err
+			}
+			mfConfig.Draft = draftDir
 		}
 
 		quantize, _ := cmd.Flags().GetString("quantize")
 		return xcreateclient.CreateModel(xcreateclient.CreateOptions{
-			ModelName: modelName,
+			ModelName:     modelName,
-			ModelDir:  modelDir,
+			ModelDir:      modelDir,
-			Quantize:  quantize,
+			Quantize:      quantize,
-			Modelfile: mfConfig,
+			DraftQuantize: draftQuantize,
+			Modelfile:     mfConfig,
 		}, p)
 	}
 
@@ -2176,6 +2219,9 @@ func NewCLI() *cobra.Command {
 			if experimental, _ := cmd.Flags().GetBool("experimental"); experimental {
 				return nil
 			}
+			if draftQuantize, _ := cmd.Flags().GetString("draft-quantize"); draftQuantize != "" {
+				return errors.New("--draft-quantize requires --experimental")
+			}
 			return checkServerHeartbeat(cmd, args)
 		},
 		RunE: CreateHandler,
@@ -2183,6 +2229,7 @@ func NewCLI() *cobra.Command {
 
 	createCmd.Flags().StringP("file", "f", "", "Name of the Modelfile (default \"Modelfile\")")
 	createCmd.Flags().StringP("quantize", "q", "", "Quantize model to this level (e.g. q4_K_M)")
+	createCmd.Flags().String("draft-quantize", "", "Quantize draft model to this level")
 	createCmd.Flags().Bool("experimental", false, "Enable experimental safetensors model creation")
 
 	showCmd := &cobra.Command{

cmd/cmd_test.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"os"
+	"path/filepath"
 	"reflect"
 	"strings"
 	"testing"
@@ -1524,6 +1525,87 @@ func TestCreateHandler(t *testing.T) {
 	}
 }
 
+func TestCreateHandlerDraftQuantizeRequiresExperimental(t *testing.T) {
+	cmd := &cobra.Command{}
+	cmd.Flags().Bool("experimental", false, "")
+	cmd.Flags().String("draft-quantize", "mxfp8", "")
+	cmd.SetContext(t.Context())
+
+	err := CreateHandler(cmd, []string{"test-model"})
+	if err == nil || !strings.Contains(err.Error(), "--draft-quantize requires --experimental") {
+		t.Fatalf("error = %v, want draft-quantize requires experimental", err)
+	}
+}
+
+func TestCreateHandlerDraftRequiresExperimental(t *testing.T) {
+	dir := t.TempDir()
+	modelfile := filepath.Join(dir, "Modelfile")
+	if err := os.WriteFile(modelfile, []byte("FROM base\nDRAFT ./assistant\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	cmd := &cobra.Command{}
+	cmd.Flags().Bool("experimental", false, "")
+	cmd.Flags().String("draft-quantize", "", "")
+	cmd.Flags().String("file", modelfile, "")
+	cmd.SetContext(t.Context())
+
+	err := CreateHandler(cmd, []string{"test-model"})
+	if err == nil || !strings.Contains(err.Error(), "DRAFT requires --experimental") {
+		t.Fatalf("error = %v, want DRAFT requires --experimental", err)
+	}
+}
+
+func TestResolveExperimentalLocalModelDir(t *testing.T) {
+	dir := t.TempDir()
+	modelfile := filepath.Join(dir, "Modelfile")
+	modelDir := filepath.Join(dir, "model")
+	if err := os.Mkdir(modelDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(modelDir, "config.json"), []byte(`{}`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(modelDir, "model.safetensors"), []byte("dummy"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	if got := resolveExperimentalLocalModelDir("gemma4", modelfile); got != "gemma4" {
+		t.Fatalf("resolveExperimentalLocalModelDir(model name) = %q, want gemma4", got)
+	}
+	if got := resolveExperimentalLocalModelDir("./model", modelfile); got != modelDir {
+		t.Fatalf("resolveExperimentalLocalModelDir(local dir) = %q, want %q", got, modelDir)
+	}
+}
+
+func TestResolveExperimentalDraftDir(t *testing.T) {
+	dir := t.TempDir()
+	modelfile := filepath.Join(dir, "Modelfile")
+	draftDir := filepath.Join(dir, "assistant")
+	if err := os.Mkdir(draftDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(draftDir, "config.json"), []byte(`{}`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(draftDir, "model.safetensors"), []byte("dummy"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := resolveExperimentalDraftDir("./assistant", modelfile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != draftDir {
+		t.Fatalf("resolveExperimentalDraftDir(local dir) = %q, want %q", got, draftDir)
+	}
+
+	_, err = resolveExperimentalDraftDir("assistant-model", modelfile)
+	if err == nil || !strings.Contains(err.Error(), "DRAFT model references are not supported with --experimental yet") {
+		t.Fatalf("error = %v, want unsupported draft model reference", err)
+	}
+}
+
 func TestNewCreateRequest(t *testing.T) {
 	tests := []struct {
 		name     string

parser/parser.go

@@ -83,6 +83,8 @@ func (f Modelfile) CreateRequest(relativeDir string) (*api.CreateRequest, error)
 					req.Files[k] = v
 				}
 			}
+		case "draft":
+			return nil, errors.New("DRAFT requires --experimental")
 		case "adapter":
 			path, err := expandPath(c.Args, relativeDir)
 			if err != nil {
@@ -336,7 +338,7 @@ func (c Command) String() string {
 	switch c.Name {
 	case "model":
 		fmt.Fprintf(&sb, "FROM %s", c.Args)
-	case "license", "template", "system", "adapter", "renderer", "parser", "requires":
+	case "license", "template", "system", "adapter", "renderer", "parser", "requires", "draft":
 		fmt.Fprintf(&sb, "%s %s", strings.ToUpper(c.Name), quote(c.Args))
 	case "message":
 		role, message, _ := strings.Cut(c.Args, ": ")
@@ -362,7 +364,7 @@ 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\", \"renderer\", \"parser\", \"parameter\", \"message\", or \"requires\"")
+	errInvalidCommand     = errors.New("command must be one of \"from\", \"license\", \"template\", \"system\", \"adapter\", \"draft\", \"renderer\", \"parser\", \"parameter\", \"message\", or \"requires\"")
 )
 
 type ParserError struct {
@@ -622,7 +624,7 @@ func isValidMessageRole(role string) bool {
 
 func isValidCommand(cmd string) bool {
 	switch strings.ToLower(cmd) {
-	case "from", "license", "template", "system", "adapter", "renderer", "parser", "parameter", "message", "requires":
+	case "from", "license", "template", "system", "adapter", "draft", "renderer", "parser", "parameter", "message", "requires":
 		return true
 	default:
 		return false

parser/parser_test.go

@@ -58,6 +58,32 @@ TEMPLATE """{{ if .System }}<|start_header_id|>system<|end_header_id|>
 	assert.Equal(t, expectedCommands, modelfile.Commands)
 }
 
+func TestParseFileDraft(t *testing.T) {
+	modelfile, err := ParseFile(strings.NewReader(`
+FROM base
+DRAFT ./assistant
+`))
+	require.NoError(t, err)
+
+	expectedCommands := []Command{
+		{Name: "model", Args: "base"},
+		{Name: "draft", Args: "./assistant"},
+	}
+	assert.Equal(t, expectedCommands, modelfile.Commands)
+	assert.Contains(t, modelfile.String(), "DRAFT ./assistant")
+}
+
+func TestCreateRequestDraftRequiresExperimental(t *testing.T) {
+	modelfile, err := ParseFile(strings.NewReader(`
+FROM base
+DRAFT ./assistant
+`))
+	require.NoError(t, err)
+
+	_, err = modelfile.CreateRequest("")
+	require.ErrorContains(t, err, "DRAFT requires --experimental")
+}
+
 func TestParseFileTrimSpace(t *testing.T) {
 	input := `
 FROM "     model 1"

scripts/build_linux.sh

@@ -62,13 +62,15 @@ if echo $PLATFORM | grep "," > /dev/null ; then
         tar c -C ./dist/linux_arm64 --exclude cuda_jetpack5 --exclude cuda_jetpack6 . | zstd --ultra -22 -T0 >./dist/ollama-linux-arm64.tar.zst
         tar c -C ./dist/linux_arm64 ./lib/ollama/cuda_jetpack5  | zstd --ultra -22 -T0 >./dist/ollama-linux-arm64-jetpack5.tar.zst
         tar c -C ./dist/linux_arm64 ./lib/ollama/cuda_jetpack6  | zstd --ultra -22 -T0 >./dist/ollama-linux-arm64-jetpack6.tar.zst
-        tar c -C ./dist/linux_amd64 --exclude rocm . | zstd --ultra -22 -T0 >./dist/ollama-linux-amd64.tar.zst
+        tar c -C ./dist/linux_amd64 --exclude rocm --exclude 'mlx*' --exclude include . | zstd --ultra -22 -T0 >./dist/ollama-linux-amd64.tar.zst
         tar c -C ./dist/linux_amd64 ./lib/ollama/rocm  | zstd --ultra -22 -T0 >./dist/ollama-linux-amd64-rocm.tar.zst
+        tar c -C ./dist/linux_amd64 ./lib/ollama/mlx_cuda_v13 ./lib/ollama/include  | zstd --ultra -22 -T0 >./dist/ollama-linux-amd64-mlx.tar.zst
 elif echo $PLATFORM | grep "arm64" > /dev/null ; then
         tar c -C ./dist/ --exclude cuda_jetpack5 --exclude cuda_jetpack6 bin lib | zstd --ultra -22 -T0 >./dist/ollama-linux-arm64.tar.zst
         tar c -C ./dist/ ./lib/ollama/cuda_jetpack5  | zstd --ultra -22 -T0 >./dist/ollama-linux-arm64-jetpack5.tar.zst
         tar c -C ./dist/ ./lib/ollama/cuda_jetpack6  | zstd --ultra -22 -T0 >./dist/ollama-linux-arm64-jetpack6.tar.zst
 elif echo $PLATFORM | grep "amd64" > /dev/null ; then
-        tar c -C ./dist/ --exclude rocm bin lib | zstd --ultra -22 -T0 >./dist/ollama-linux-amd64.tar.zst
+        tar c -C ./dist/ --exclude rocm --exclude 'mlx*' --exclude include bin lib | zstd --ultra -22 -T0 >./dist/ollama-linux-amd64.tar.zst
         tar c -C ./dist/ ./lib/ollama/rocm  | zstd --ultra -22 -T0 >./dist/ollama-linux-amd64-rocm.tar.zst
+        tar c -C ./dist/ ./lib/ollama/mlx_cuda_v13 ./lib/ollama/include  | zstd --ultra -22 -T0 >./dist/ollama-linux-amd64-mlx.tar.zst
 fi

types/model/config.go

@@ -19,6 +19,7 @@ type ConfigV2 struct {
 	ContextLen   int      `json:"context_length,omitempty"`
 	EmbedLen     int      `json:"embedding_length,omitempty"`
 	BaseName     string   `json:"base_name,omitempty"`
+	Draft        *Draft   `json:"draft,omitempty"`
 
 	// required by spec
 	Architecture string `json:"architecture"`
@@ -26,6 +27,14 @@ type ConfigV2 struct {
 	RootFS       RootFS `json:"rootfs"`
 }
 
+// Draft describes an auxiliary draft model stored in the same manifest.
+type Draft struct {
+	ModelFormat  string `json:"model_format,omitempty"`
+	Architecture string `json:"architecture,omitempty"`
+	TensorPrefix string `json:"tensor_prefix,omitempty"`
+	Config       string `json:"config,omitempty"`
+}
+
 // RootFS represents the root filesystem configuration for a model.
 type RootFS struct {
 	Type    string   `json:"type"`

x/create/client/create.go

@@ -23,6 +23,7 @@ import (
 	"github.com/ollama/ollama/progress"
 	"github.com/ollama/ollama/types/model"
 	"github.com/ollama/ollama/x/create"
+	imagemanifest "github.com/ollama/ollama/x/imagegen/manifest"
 	"github.com/ollama/ollama/x/safetensors"
 )
 
@@ -34,6 +35,7 @@ type ModelfileConfig struct {
 	Template   string
 	System     string
 	License    string
+	Draft      string
 	Parser     string
 	Renderer   string
 	Parameters map[string]any
@@ -67,6 +69,8 @@ func ConfigFromModelfile(modelfile *parser.Modelfile) (string, *ModelfileConfig,
 			mfConfig.System = cmd.Args
 		case "license":
 			mfConfig.License = cmd.Args
+		case "draft":
+			mfConfig.Draft = cmd.Args
 		case "parser":
 			mfConfig.Parser = cmd.Args
 		case "renderer":
@@ -108,10 +112,12 @@ func ConfigFromModelfile(modelfile *parser.Modelfile) (string, *ModelfileConfig,
 
 // CreateOptions holds all options for model creation.
 type CreateOptions struct {
-	ModelName string
+	ModelName     string
-	ModelDir  string
+	ModelDir      string
-	Quantize  string           // "int4", "int8", "nvfp4", "mxfp4", or "mxfp8" for quantization
+	Quantize      string           // "int4", "int8", "nvfp4", "mxfp4", or "mxfp8" for quantization
-	Modelfile *ModelfileConfig // template/system/license/parser/renderer/parameters from Modelfile
+	DraftQuantize string           // optional quantization level for draft model tensors
+	Modelfile     *ModelfileConfig // template/system/license/parser/renderer/parameters from Modelfile
+	BaseConfig    *model.ConfigV2
 }
 
 // CreateModel imports a model from a local directory.
@@ -121,11 +127,23 @@ func CreateModel(opts CreateOptions, p *progress.Progress) error {
 	// Detect model type
 	isSafetensors := create.IsSafetensorsModelDir(opts.ModelDir)
 	isImageGen := create.IsTensorModelDir(opts.ModelDir)
+	hasDraft := opts.Modelfile != nil && opts.Modelfile.Draft != ""
+	isBaseModelWithDraft := hasDraft && !isSafetensors && create.IsSafetensorsLLMModel(opts.ModelDir)
+	if opts.DraftQuantize != "" && !hasDraft {
+		return fmt.Errorf("--draft-quantize requires a DRAFT model")
+	}
 
-	if !isSafetensors && !isImageGen {
+	if !isSafetensors && !isImageGen && !isBaseModelWithDraft {
 		return fmt.Errorf("%s is not a supported model directory (needs config.json + *.safetensors or model_index.json)", opts.ModelDir)
 	}
 
+	if hasDraft && !create.IsSafetensorsModelDir(opts.Modelfile.Draft) {
+		return fmt.Errorf("draft %s is not a supported safetensors model directory", opts.Modelfile.Draft)
+	}
+	if hasDraft && isImageGen {
+		return fmt.Errorf("draft models are only supported for safetensors LLM models")
+	}
+
 	// Determine model type settings
 	var modelType, spinnerKey string
 	var capabilities []string
@@ -138,6 +156,9 @@ func CreateModel(opts CreateOptions, p *progress.Progress) error {
 		parserName = getParserName(opts.ModelDir)
 		rendererName = getRendererName(opts.ModelDir)
 		capabilities = inferSafetensorsCapabilities(opts.ModelDir, resolveParserName(opts.Modelfile, parserName))
+	} else if isBaseModelWithDraft {
+		modelType = "safetensors model"
+		spinnerKey = "create"
 	} else {
 		modelType = "image generation model"
 		spinnerKey = "imagegen"
@@ -156,13 +177,44 @@ func CreateModel(opts CreateOptions, p *progress.Progress) error {
 		p.Add(spinnerKey, spinner)
 	}
 
-	// Create the model using shared callbacks
+	var draftLayers []create.LayerInfo
 	var err error
+	if hasDraft {
+		draftLayers, err = create.CreateDraftSafetensorsLayers(
+			opts.Modelfile.Draft,
+			"draft.",
+			"draft",
+			opts.DraftQuantize,
+			newLayerCreator(),
+			newTensorLayerCreator(),
+			progressFn,
+		)
+		if err != nil {
+			spinner.Stop()
+			return err
+		}
+	}
+
+	if isBaseModelWithDraft {
+		err = createModelFromBaseWithDraft(opts, draftLayers, progressFn)
+		spinner.Stop()
+		if err != nil {
+			return err
+		}
+		fmt.Printf("Created safetensors model '%s'\n", opts.ModelName)
+		return nil
+	}
+
+	// Create the model using shared callbacks
 	if isSafetensors {
+		writer := newManifestWriter(opts, capabilities, parserName, rendererName)
+		if len(draftLayers) > 0 {
+			writer = appendLayersManifestWriter(writer, draftLayers)
+		}
 		err = create.CreateSafetensorsModel(
 			opts.ModelName, opts.ModelDir, opts.Quantize,
 			newLayerCreator(), newTensorLayerCreator(),
-			newManifestWriter(opts, capabilities, parserName, rendererName),
+			writer,
 			progressFn,
 			newPackedTensorLayerCreator(),
 		)
@@ -184,6 +236,68 @@ func CreateModel(opts CreateOptions, p *progress.Progress) error {
 	return nil
 }
 
+func appendLayersManifestWriter(next create.ManifestWriter, extra []create.LayerInfo) create.ManifestWriter {
+	return func(modelName string, config create.LayerInfo, layers []create.LayerInfo) error {
+		layers = append(layers, extra...)
+		return next(modelName, config, layers)
+	}
+}
+
+func createModelFromBaseWithDraft(opts CreateOptions, draftLayers []create.LayerInfo, progressFn func(string)) error {
+	progressFn(fmt.Sprintf("loading base model %s", opts.ModelDir))
+	baseManifest, err := imagemanifest.LoadManifest(opts.ModelDir)
+	if err != nil {
+		return err
+	}
+
+	baseConfig, err := readConfigV2(baseManifest)
+	if err != nil {
+		return err
+	}
+	opts.BaseConfig = baseConfig
+
+	configLayer := baseManifest.GetConfigLayer("config.json")
+	if configLayer == nil {
+		return fmt.Errorf("base model %s does not contain config.json", opts.ModelDir)
+	}
+
+	layers := make([]create.LayerInfo, 0, len(baseManifest.Manifest.Layers)+len(draftLayers))
+	for _, layer := range baseManifest.Manifest.Layers {
+		layers = append(layers, create.LayerInfo{
+			Digest:    layer.Digest,
+			Size:      layer.Size,
+			MediaType: layer.MediaType,
+			Name:      layer.Name,
+		})
+	}
+	layers = append(layers, draftLayers...)
+
+	progressFn(fmt.Sprintf("writing manifest for %s", opts.ModelName))
+	return newManifestWriter(opts, baseConfig.Capabilities, baseConfig.Parser, baseConfig.Renderer)(
+		opts.ModelName,
+		create.LayerInfo{
+			Digest:    configLayer.Digest,
+			Size:      configLayer.Size,
+			MediaType: configLayer.MediaType,
+			Name:      configLayer.Name,
+		},
+		layers,
+	)
+}
+
+func readConfigV2(m *imagemanifest.ModelManifest) (*model.ConfigV2, error) {
+	data, err := os.ReadFile(m.BlobPath(m.Manifest.Config.Digest))
+	if err != nil {
+		return nil, fmt.Errorf("failed to read base config: %w", err)
+	}
+
+	var cfg model.ConfigV2
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return nil, fmt.Errorf("failed to parse base config: %w", err)
+	}
+	return &cfg, nil
+}
+
 func inferSafetensorsCapabilities(modelDir, parserName string) []string {
 	capabilities := []string{"completion"}
 
@@ -359,14 +473,26 @@ func newManifestWriter(opts CreateOptions, capabilities []string, parserName, re
 			}
 		}
 
-		// Create config blob with version requirement
+		// Create config blob with version requirement.
-		configData := model.ConfigV2{
+		configData := model.ConfigV2{}
-			ModelFormat:  "safetensors",
+		if opts.BaseConfig != nil {
-			FileType:     strings.ToLower(strings.TrimSpace(opts.Quantize)),
+			configData = *opts.BaseConfig
-			Capabilities: caps,
+		}
-			Requires:     MinOllamaVersion,
+		configData.ModelFormat = "safetensors"
-			Parser:       resolveParserName(opts.Modelfile, parserName),
+		if opts.Quantize != "" || configData.FileType == "" {
-			Renderer:     resolveRendererName(opts.Modelfile, rendererName),
+			configData.FileType = strings.ToLower(strings.TrimSpace(opts.Quantize))
+		}
+		configData.Capabilities = caps
+		configData.Requires = MinOllamaVersion
+		configData.Parser = resolveParserName(opts.Modelfile, parserName)
+		configData.Renderer = resolveRendererName(opts.Modelfile, rendererName)
+		if opts.Modelfile != nil && opts.Modelfile.Draft != "" {
+			configData.Draft = &model.Draft{
+				ModelFormat:  "safetensors",
+				Architecture: "Gemma4AssistantForCausalLM",
+				TensorPrefix: "draft.",
+				Config:       "draft/config.json",
+			}
 		}
 		configJSON, err := json.Marshal(configData)
 		if err != nil {

x/create/client/create_test.go

@@ -44,6 +44,7 @@ func TestModelfileConfig(t *testing.T) {
 func TestConfigFromModelfile(t *testing.T) {
 	modelfile, err := parser.ParseFile(strings.NewReader(`
 FROM ./model
+DRAFT ./assistant
 TEMPLATE {{ .Prompt }}
 PARAMETER temperature 0.7
 PARAMETER stop USER:
@@ -66,6 +67,10 @@ PARAMETER stop ASSISTANT:
 		t.Fatalf("Template = %q, want %q", mfConfig.Template, "{{ .Prompt }}")
 	}
 
+	if mfConfig.Draft != "./assistant" {
+		t.Fatalf("Draft = %q, want %q", mfConfig.Draft, "./assistant")
+	}
+
 	if got := mfConfig.Parameters["temperature"]; got != float32(0.7) {
 		t.Fatalf("temperature = %#v, want %v", got, float32(0.7))
 	}
@@ -153,11 +158,23 @@ func TestCreateModel_NotSafetensorsDir(t *testing.T) {
 	}
 }
 
+func TestCreateModel_DraftQuantizeRequiresDraft(t *testing.T) {
+	err := CreateModel(CreateOptions{
+		ModelName:     "test-model",
+		ModelDir:      t.TempDir(),
+		DraftQuantize: "mxfp8",
+	}, nil)
+	if err == nil || !strings.Contains(err.Error(), "--draft-quantize requires a DRAFT model") {
+		t.Fatalf("error = %v, want draft-quantize requires DRAFT", err)
+	}
+}
+
 func TestCreateOptions(t *testing.T) {
 	opts := CreateOptions{
-		ModelName: "my-model",
+		ModelName:     "my-model",
-		ModelDir:  "/path/to/model",
+		ModelDir:      "/path/to/model",
-		Quantize:  "fp8",
+		Quantize:      "fp8",
+		DraftQuantize: "mxfp8",
 		Modelfile: &ModelfileConfig{
 			Template: "test",
 			System:   "system",
@@ -179,6 +196,9 @@ func TestCreateOptions(t *testing.T) {
 	if opts.Quantize != "fp8" {
 		t.Errorf("Quantize = %q, want %q", opts.Quantize, "fp8")
 	}
+	if opts.DraftQuantize != "mxfp8" {
+		t.Errorf("DraftQuantize = %q, want %q", opts.DraftQuantize, "mxfp8")
+	}
 	if opts.Modelfile == nil {
 		t.Error("Modelfile should not be nil")
 	}
@@ -286,6 +306,9 @@ func TestCreateOptions_Defaults(t *testing.T) {
 	if opts.Quantize != "" {
 		t.Errorf("Quantize should be empty by default, got %q", opts.Quantize)
 	}
+	if opts.DraftQuantize != "" {
+		t.Errorf("DraftQuantize should be empty by default, got %q", opts.DraftQuantize)
+	}
 
 	// Modelfile should default to nil
 	if opts.Modelfile != nil {
@@ -518,6 +541,48 @@ func TestNewManifestWriter_PopulatesFileTypeFromQuantize(t *testing.T) {
 	}
 }
 
+func TestNewManifestWriter_PopulatesDraftMetadata(t *testing.T) {
+	t.Setenv("OLLAMA_MODELS", t.TempDir())
+
+	opts := CreateOptions{
+		ModelName: "test-draft",
+		ModelDir:  t.TempDir(),
+		Modelfile: &ModelfileConfig{Draft: "/tmp/assistant"},
+	}
+
+	writer := newManifestWriter(opts, []string{"completion"}, "gemma4", "gemma4")
+	if err := writer(opts.ModelName, create.LayerInfo{}, nil); err != nil {
+		t.Fatalf("newManifestWriter() error = %v", err)
+	}
+
+	name := model.ParseName(opts.ModelName)
+	mf, err := manifest.ParseNamedManifest(name)
+	if err != nil {
+		t.Fatalf("ParseNamedManifest() error = %v", err)
+	}
+
+	configPath, err := manifest.BlobsPath(mf.Config.Digest)
+	if err != nil {
+		t.Fatalf("BlobsPath() error = %v", err)
+	}
+
+	data, err := os.ReadFile(configPath)
+	if err != nil {
+		t.Fatalf("ReadFile() error = %v", err)
+	}
+
+	var cfg model.ConfigV2
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		t.Fatalf("Unmarshal() error = %v", err)
+	}
+	if cfg.Draft == nil {
+		t.Fatal("Draft metadata missing")
+	}
+	if cfg.Draft.TensorPrefix != "draft." || cfg.Draft.Config != "draft/config.json" {
+		t.Fatalf("Draft = %#v, want draft prefix/config", cfg.Draft)
+	}
+}
+
 func TestSupportsThinking(t *testing.T) {
 	tests := []struct {
 		name       string

x/create/create.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"math"
 	"os"
+	"path"
 	"path/filepath"
 	"regexp"
 	"slices"
@@ -724,12 +725,16 @@ func detectModelOptQuantization(modelDir string) bool {
 }
 
 func resolveEffectiveQuantization(cfg sourceModelConfig, sourceKind sourceQuantizedKind, requested string) (string, error) {
+	return resolveEffectiveQuantizationForFlag(cfg, sourceKind, requested, "--quantize")
+}
+
+func resolveEffectiveQuantizationForFlag(cfg sourceModelConfig, sourceKind sourceQuantizedKind, requested, flagName string) (string, error) {
 	switch sourceKind {
 	case sourceQuantizedKindNone:
 		return requested, nil
 	case sourceQuantizedKindPrequantized:
 		if requested != "" {
-			return "", fmt.Errorf("cannot requantize already-quantized source model with --quantize %q", requested)
+			return "", fmt.Errorf("cannot requantize already-quantized source model with %s %q", flagName, requested)
 		}
 		return "", nil
 	case sourceQuantizedKindSourceFP8:
@@ -746,7 +751,7 @@ func resolveEffectiveQuantization(cfg sourceModelConfig, sourceKind sourceQuanti
 			case "nvfp4", "mxfp4", "mxfp8":
 				return requested, nil
 			default:
-				return "", fmt.Errorf("cannot convert already-quantized fp8 source model with --quantize %q", requested)
+				return "", fmt.Errorf("cannot convert already-quantized fp8 source model with %s %q", flagName, requested)
 			}
 		}
 		return "mxfp8", nil
@@ -810,6 +815,7 @@ var tensorImportTransformRegistry = map[string]tensorImportTransformFactory{
 	"Gemma4ForCausalLM":                    newGemma4ImportTransform,
 	"Gemma4ForConditionalGeneration":       newGemma4ImportTransform,
 	"LagunaForCausalLM":                    newLagunaImportTransform,
+	"Gemma4AssistantForCausalLM":           newGemma4ImportTransform,
 }
 
 func newTensorImportTransform(modelDir string, cfg sourceModelConfig) (tensorImportTransform, error) {
@@ -1167,6 +1173,136 @@ func CreateSafetensorsModel(modelName, modelDir, quantize string, createLayer La
 	return nil
 }
 
+func normalizeRequestedQuantization(flagName, quantize string) (string, error) {
+	q := normalizeQuantType(strings.TrimSpace(quantize))
+	switch q {
+	case "", "int4", "int8", "nvfp4", "mxfp4", "mxfp8":
+		return q, nil
+	default:
+		return "", fmt.Errorf("unsupported %s %q: supported types are int4, int8, nvfp4, mxfp4, mxfp8", flagName, quantize)
+	}
+}
+
+// CreateDraftSafetensorsLayers imports an assistant/draft safetensors model
+// into prefixed tensor and config layers. When draftQuantize is non-empty,
+// eligible draft tensors are quantized with the same per-architecture policy
+// used by target safetensors imports.
+func CreateDraftSafetensorsLayers(modelDir, tensorPrefix, configPrefix, draftQuantize string, createLayer LayerCreator, createTensorLayer QuantizingTensorLayerCreator, fn func(status string)) ([]LayerInfo, error) {
+	if tensorPrefix == "" {
+		return nil, fmt.Errorf("draft tensor prefix must not be empty")
+	}
+	if configPrefix == "" {
+		return nil, fmt.Errorf("draft config prefix must not be empty")
+	}
+	effectiveQuantize, err := normalizeRequestedQuantization("--draft-quantize", draftQuantize)
+	if err != nil {
+		return nil, err
+	}
+
+	var importTransform tensorImportTransform = noopImportTransform{}
+	if effectiveQuantize != "" {
+		sourceConfig, err := readSourceModelConfig(modelDir)
+		if err != nil {
+			return nil, fmt.Errorf("failed to read draft config.json: %w", err)
+		}
+		sourceQuantKind, err := inspectSourceQuantization(modelDir, sourceConfig)
+		if err != nil {
+			return nil, fmt.Errorf("failed to inspect draft quantization: %w", err)
+		}
+		effectiveQuantize, err = resolveEffectiveQuantizationForFlag(sourceConfig, sourceQuantKind, effectiveQuantize, "--draft-quantize")
+		if err != nil {
+			return nil, err
+		}
+		importTransform, err = newTensorImportTransform(modelDir, sourceConfig)
+		if err != nil {
+			return nil, fmt.Errorf("failed to construct draft import transform for architecture %q: %w", sourceConfig.Architecture(), err)
+		}
+	}
+
+	entries, err := os.ReadDir(modelDir)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read draft directory: %w", err)
+	}
+
+	var layers []LayerInfo
+	for _, entry := range entries {
+		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".safetensors") {
+			continue
+		}
+
+		stPath := filepath.Join(modelDir, entry.Name())
+		extractor, err := safetensors.OpenForExtraction(stPath)
+		if err != nil {
+			return nil, fmt.Errorf("failed to open draft %s: %w", stPath, err)
+		}
+
+		tensorNames := extractor.ListTensors()
+		fn(fmt.Sprintf("importing draft %s (%d tensors%s)", entry.Name(), len(tensorNames), importQuantizationStatus(sourceQuantizedKindNone, effectiveQuantize)))
+		for _, tensorName := range tensorNames {
+			if importTransform.skipTensor(tensorName) {
+				continue
+			}
+			td, err := extractor.GetTensor(tensorName)
+			if err != nil {
+				extractor.Close()
+				return nil, fmt.Errorf("failed to get draft tensor %s: %w", tensorName, err)
+			}
+
+			outTDs, err := importTransform.transformTensor(td)
+			if err != nil {
+				extractor.Close()
+				return nil, fmt.Errorf("failed to transform draft tensor %s: %w", tensorName, err)
+			}
+			for _, transformedTD := range outTDs {
+				if transformedTD == nil {
+					continue
+				}
+				outTD := transformedTD.WithName(tensorPrefix + transformedTD.Name)
+				quantizeType := ""
+				if effectiveQuantize != "" {
+					quantizeType = importTransform.quantizationType(outTD.Name, outTD.Shape, effectiveQuantize)
+					if isEmbedTokensWeight(outTD.Name) {
+						quantizeType = ""
+					}
+				}
+				newLayers, err := createTensorLayer(outTD.SafetensorsReader(), outTD.Name, outTD.Dtype, outTD.Shape, quantizeType)
+				if err != nil {
+					extractor.Close()
+					return nil, fmt.Errorf("failed to create draft layer for %s: %w", tensorName, err)
+				}
+				layers = append(layers, newLayers...)
+			}
+		}
+		extractor.Close()
+	}
+
+	for _, entry := range entries {
+		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".json") {
+			continue
+		}
+		if entry.Name() == "model.safetensors.index.json" {
+			continue
+		}
+
+		cfgPath := entry.Name()
+		fullPath := filepath.Join(modelDir, cfgPath)
+		fn(fmt.Sprintf("importing draft config %s", cfgPath))
+
+		f, err := os.Open(fullPath)
+		if err != nil {
+			return nil, fmt.Errorf("failed to open draft %s: %w", cfgPath, err)
+		}
+		layer, err := createLayer(f, "application/vnd.ollama.image.json", path.Join(configPrefix, cfgPath))
+		f.Close()
+		if err != nil {
+			return nil, fmt.Errorf("failed to create draft config layer for %s: %w", cfgPath, err)
+		}
+		layers = append(layers, layer)
+	}
+
+	return layers, nil
+}
+
 func shouldSkipSourceCompanion(name string, tensorSet map[string]struct{}, sourceTensorFiles map[string]string) bool {
 	switch {
 	case strings.HasSuffix(name, ".scales"):

x/create/create_test.go

@@ -452,6 +452,137 @@ func TestCreateSafetensorsModel(t *testing.T) {
 	}
 }
 
+func TestCreateDraftSafetensorsLayersPrefixesTensorsAndConfigs(t *testing.T) {
+	dir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dir, "config.json"), []byte(`{"model_type":"gemma4_assistant"}`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	createTestSafetensors(t, filepath.Join(dir, "model.safetensors"), []*st.TensorData{
+		st.NewTensorDataFromBytes("model.layers.0.self_attn.q_proj.weight", "BF16", []int32{2, 2}, make([]byte, 8)),
+	})
+
+	var tensorNames []string
+	createLayer := func(r io.Reader, mediaType, name string) (LayerInfo, error) {
+		data, err := io.ReadAll(r)
+		if err != nil {
+			return LayerInfo{}, err
+		}
+		return LayerInfo{Digest: "sha256:json_" + name, Size: int64(len(data)), MediaType: mediaType, Name: name}, nil
+	}
+	createTensorLayer := func(r io.Reader, name, dtype string, shape []int32, quantize string) ([]LayerInfo, error) {
+		data, err := io.ReadAll(r)
+		if err != nil {
+			return nil, err
+		}
+		tensorNames = append(tensorNames, name)
+		tensorName, tensorShape := readSingleTensorNameAndShape(t, data)
+		if tensorName != name {
+			t.Fatalf("safetensors key = %q, want %q", tensorName, name)
+		}
+		if !slices.Equal(tensorShape, shape) {
+			t.Fatalf("shape = %v, want %v", tensorShape, shape)
+		}
+		if quantize != "" {
+			t.Fatalf("draft quantize = %q, want empty", quantize)
+		}
+		return []LayerInfo{{Digest: "sha256:tensor_" + name, Size: int64(len(data)), MediaType: "application/vnd.ollama.image.tensor", Name: name}}, nil
+	}
+
+	layers, err := CreateDraftSafetensorsLayers(dir, "draft.", "draft", "", createLayer, createTensorLayer, func(string) {})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !slices.Contains(tensorNames, "draft.model.layers.0.self_attn.q_proj.weight") {
+		t.Fatalf("draft tensor was not prefixed: %v", tensorNames)
+	}
+	var hasDraftConfig bool
+	for _, layer := range layers {
+		if layer.Name == "draft/config.json" && layer.MediaType == "application/vnd.ollama.image.json" {
+			hasDraftConfig = true
+		}
+	}
+	if !hasDraftConfig {
+		t.Fatalf("draft/config.json layer missing: %#v", layers)
+	}
+}
+
+func TestCreateDraftSafetensorsLayersQuantizesEligibleTensors(t *testing.T) {
+	dir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dir, "config.json"), []byte(`{
+		"architectures":["Gemma4AssistantForCausalLM"],
+		"num_hidden_layers":8
+	}`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	createTestSafetensors(t, filepath.Join(dir, "model.safetensors"), []*st.TensorData{
+		st.NewTensorDataFromBytes("model.embed_tokens.weight", "BF16", []int32{64, 64}, make([]byte, 64*64*2)),
+		st.NewTensorDataFromBytes("model.layers.0.self_attn.q_proj.weight", "BF16", []int32{64, 64}, make([]byte, 64*64*2)),
+		st.NewTensorDataFromBytes("model.layers.0.input_layernorm.weight", "BF16", []int32{64}, make([]byte, 64*2)),
+	})
+
+	createLayer := func(r io.Reader, mediaType, name string) (LayerInfo, error) {
+		data, err := io.ReadAll(r)
+		if err != nil {
+			return LayerInfo{}, err
+		}
+		return LayerInfo{Digest: "sha256:json_" + name, Size: int64(len(data)), MediaType: mediaType, Name: name}, nil
+	}
+	quantizeByName := make(map[string]string)
+	createTensorLayer := func(r io.Reader, name, dtype string, shape []int32, quantize string) ([]LayerInfo, error) {
+		data, err := io.ReadAll(r)
+		if err != nil {
+			return nil, err
+		}
+		quantizeByName[name] = quantize
+		return []LayerInfo{{Digest: "sha256:tensor_" + name, Size: int64(len(data)), MediaType: "application/vnd.ollama.image.tensor", Name: name}}, nil
+	}
+
+	if _, err := CreateDraftSafetensorsLayers(dir, "draft.", "draft", "MXFP8", createLayer, createTensorLayer, func(string) {}); err != nil {
+		t.Fatal(err)
+	}
+
+	if got := quantizeByName["draft.model.layers.0.self_attn.q_proj.weight"]; got != "mxfp8" {
+		t.Fatalf("q_proj draft quantize = %q, want mxfp8", got)
+	}
+	if got := quantizeByName["draft.model.layers.0.input_layernorm.weight"]; got != "" {
+		t.Fatalf("norm draft quantize = %q, want empty", got)
+	}
+	if got := quantizeByName["draft.model.embed_tokens.weight"]; got != "" {
+		t.Fatalf("embed_tokens draft quantize = %q, want empty", got)
+	}
+}
+
+func TestCreateDraftSafetensorsLayersRejectsUnsupportedDraftQuantize(t *testing.T) {
+	_, err := CreateDraftSafetensorsLayers(t.TempDir(), "draft.", "draft", "bogus", nil, nil, func(string) {})
+	if err == nil || !strings.Contains(err.Error(), "unsupported --draft-quantize") {
+		t.Fatalf("error = %v, want unsupported --draft-quantize", err)
+	}
+}
+
+func readSingleTensorNameAndShape(t *testing.T, data []byte) (string, []int32) {
+	t.Helper()
+
+	var headerSize uint64
+	if err := binary.Read(bytes.NewReader(data[:8]), binary.LittleEndian, &headerSize); err != nil {
+		t.Fatalf("failed to read header size: %v", err)
+	}
+
+	var header map[string]struct {
+		Shape []int32 `json:"shape"`
+	}
+	if err := json.Unmarshal(data[8:8+headerSize], &header); err != nil {
+		t.Fatalf("failed to parse header: %v", err)
+	}
+	for name, info := range header {
+		if name != "__metadata__" {
+			return name, info.Shape
+		}
+	}
+	t.Fatal("no tensor entry found in header")
+	return "", nil
+}
+
 func TestCreateSafetensorsModel_NoConfigJson(t *testing.T) {
 	dir := t.TempDir()
 

x/mlxrunner/cache/cache.go

@@ -54,6 +54,81 @@ type Attention interface {
 	Update(b *batch.Batch, keys, values *mlx.Array) *nn.KVHistory
 }
 
+// Viewer exposes a read-only attention history for a cache.
+type Viewer interface {
+	View(b *batch.Batch) *nn.KVHistory
+}
+
+type speculativeCommitter interface {
+	Cache
+	commit(n int)
+}
+
+// Speculation is an isolated cache transaction for speculative target
+// validation. Updates record generated K/V without mutating the live caches;
+// Commit appends only the accepted prefix to the live caches.
+type Speculation struct {
+	layers []speculativeCommitter
+}
+
+// BeginSpeculation returns cache wrappers suitable for a speculative target
+// forward. The returned caches must only be used for that forward.
+func BeginSpeculation(caches []Cache) ([]Cache, *Speculation, bool) {
+	specCaches := make([]Cache, len(caches))
+	layers := make([]speculativeCommitter, len(caches))
+
+	for i, c := range caches {
+		switch c := c.(type) {
+		case nil:
+		case *RotatingKVCache:
+			sc := newSpeculativeRotatingKVCache(c)
+			specCaches[i] = sc
+			layers[i] = sc
+		case *KVCache:
+			sc := newSpeculativeKVCache(c)
+			specCaches[i] = sc
+			layers[i] = sc
+		default:
+			return nil, nil, false
+		}
+	}
+
+	return specCaches, &Speculation{layers: layers}, true
+}
+
+// BeginIsolatedSpeculation returns cache wrappers that never mutate live cache
+// state. It is intended for correctness instrumentation, not the hot path.
+func BeginIsolatedSpeculation(caches []Cache) ([]Cache, bool) {
+	specCaches := make([]Cache, len(caches))
+
+	for i, c := range caches {
+		switch c := c.(type) {
+		case nil:
+		case *RotatingKVCache:
+			specCaches[i] = newSpeculativeRotatingKVCache(c)
+		case *KVCache:
+			specCaches[i] = newIsolatedKVCache(c)
+		default:
+			return nil, false
+		}
+	}
+
+	return specCaches, true
+}
+
+// Commit appends the accepted prefix from the speculative forward to the live
+// caches. The target bonus token is intentionally not committed.
+func (s *Speculation) Commit(n int) {
+	if s == nil {
+		return
+	}
+	for _, layer := range s.layers {
+		if layer != nil {
+			layer.commit(n)
+		}
+	}
+}
+
 type KVCache struct {
 	keys, values *mlx.Array
 	offset       int
@@ -70,6 +145,15 @@ func (c *KVCache) Update(_ *batch.Batch, keys, values *mlx.Array) *nn.KVHistory
 	return nn.NewKVHistory(newK, newV, nil)
 }
 
+// View returns the current cache contents as attention history without writing.
+func (c *KVCache) View(_ *batch.Batch) *nn.KVHistory {
+	state := c.State()
+	if len(state) < 2 {
+		return nil
+	}
+	return nn.NewKVHistory(state[0], state[1], nil)
+}
+
 // appendKV is the raw write path shared by Update and Restore.
 func (c *KVCache) appendKV(keys, values *mlx.Array) (*mlx.Array, *mlx.Array) {
 	B, H, L, Dk, Dv := keys.Dim(0), keys.Dim(1), keys.Dim(2), keys.Dim(3), values.Dim(3)
@@ -250,6 +334,94 @@ func (c *KVCache) Free() {
 
 func (c *KVCache) Offset() int { return c.offset }
 
+type speculativeBase struct {
+	offset int
+}
+
+func (s *speculativeBase) Free()                                 {}
+func (s *speculativeBase) Offset() int                           { return s.offset }
+func (s *speculativeBase) Snapshot(int) Snapshot                 { return nil }
+func (s *speculativeBase) Restore(Snapshot, int) bool            { return false }
+func (s *speculativeBase) Merge(parent, child Snapshot) Snapshot { return nil }
+func (s *speculativeBase) Split(snapshot Snapshot, at int) (Snapshot, Snapshot) {
+	return nil, snapshot
+}
+
+type speculativeKVCache struct {
+	speculativeBase
+	target *KVCache
+	start  int
+	end    int
+}
+
+func newSpeculativeKVCache(target *KVCache) *speculativeKVCache {
+	return &speculativeKVCache{
+		speculativeBase: speculativeBase{offset: target.Offset()},
+		target:          target,
+		start:           target.Offset(),
+		end:             target.Offset(),
+	}
+}
+
+func (c *speculativeKVCache) Update(b *batch.Batch, keys, values *mlx.Array) *nn.KVHistory {
+	history := c.target.Update(b, keys, values)
+	c.offset = c.target.Offset()
+	c.end = c.target.Offset()
+	return history
+}
+
+func (c *speculativeKVCache) State() []*mlx.Array {
+	return c.target.State()
+}
+
+func (c *speculativeKVCache) commit(n int) {
+	target := max(c.start, c.start+n)
+	if target > c.end {
+		target = c.end
+	}
+	c.target.offset = target
+	c.offset = target
+}
+
+type isolatedKVCache struct {
+	speculativeBase
+	target       *KVCache
+	keys, values *mlx.Array
+}
+
+func newIsolatedKVCache(target *KVCache) *isolatedKVCache {
+	return &isolatedKVCache{
+		speculativeBase: speculativeBase{offset: target.Offset()},
+		target:          target,
+	}
+}
+
+func (c *isolatedKVCache) Update(_ *batch.Batch, keys, values *mlx.Array) *nn.KVHistory {
+	c.keys = concatKV(c.keys, keys)
+	c.values = concatKV(c.values, values)
+	c.offset += keys.Dim(2)
+
+	state := c.target.State()
+	if len(state) < 2 {
+		return nn.NewKVHistory(c.keys, c.values, nil)
+	}
+	return nn.NewKVHistory(state[0].Concatenate(2, c.keys), state[1].Concatenate(2, c.values), nil)
+}
+
+func (c *isolatedKVCache) State() []*mlx.Array {
+	if c.keys == nil || c.values == nil {
+		return c.target.State()
+	}
+	state := c.target.State()
+	if len(state) < 2 {
+		return []*mlx.Array{c.keys, c.values}
+	}
+	return []*mlx.Array{
+		state[0].Concatenate(2, c.keys),
+		state[1].Concatenate(2, c.values),
+	}
+}
+
 // RotatingKVCache implements sliding window attention with bounded memory
 type RotatingKVCache struct {
 	maxSize int
@@ -275,6 +447,127 @@ func (c *RotatingKVCache) Update(b *batch.Batch, keys, values *mlx.Array) *nn.KV
 	})
 }
 
+// View returns the current rotating cache contents in logical order for
+// assistant KV sharing.
+func (c *RotatingKVCache) View(_ *batch.Batch) *nn.KVHistory {
+	k, v := c.logicalTail(c.maxSize - 1)
+	if k == nil || v == nil {
+		return nil
+	}
+	return nn.NewKVHistory(k, v, nil)
+}
+
+func (c *RotatingKVCache) logicalTail(keep int) (*mlx.Array, *mlx.Array) {
+	state := c.State()
+	if len(state) < 2 || keep <= 0 {
+		return nil, nil
+	}
+
+	keys, values := state[0], state[1]
+	K := keys.Dim(2)
+	if K == 0 {
+		return nil, nil
+	}
+
+	keep = min(keep, K)
+	if K > c.maxSize || c.offset < c.maxSize {
+		start := K - keep
+		return keys.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(start, K), mlx.Slice()),
+			values.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(start, K), mlx.Slice())
+	}
+
+	oldest := c.idx % K
+	var logicalK, logicalV *mlx.Array
+	if oldest == 0 {
+		logicalK, logicalV = keys, values
+	} else {
+		tailK := keys.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(oldest, K), mlx.Slice())
+		tailV := values.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(oldest, K), mlx.Slice())
+		headK := keys.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(0, oldest), mlx.Slice())
+		headV := values.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(0, oldest), mlx.Slice())
+		logicalK = tailK.Concatenate(2, headK)
+		logicalV = tailV.Concatenate(2, headV)
+	}
+
+	start := K - keep
+	return logicalK.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(start, K), mlx.Slice()),
+		logicalV.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(start, K), mlx.Slice())
+}
+
+type speculativeRotatingKVCache struct {
+	speculativeBase
+	target       *RotatingKVCache
+	keys, values *mlx.Array
+}
+
+func newSpeculativeRotatingKVCache(target *RotatingKVCache) *speculativeRotatingKVCache {
+	return &speculativeRotatingKVCache{
+		speculativeBase: speculativeBase{offset: target.Offset()},
+		target:          target,
+	}
+}
+
+func (c *speculativeRotatingKVCache) Update(b *batch.Batch, keys, values *mlx.Array) *nn.KVHistory {
+	c.keys = concatKV(c.keys, keys)
+	c.values = concatKV(c.values, values)
+	c.offset += keys.Dim(2)
+
+	oldK, oldV := c.target.logicalTail(c.target.maxSize - 1)
+	histK, histV := c.keys, c.values
+	if oldK != nil && oldV != nil {
+		histK = oldK.Concatenate(2, c.keys)
+		histV = oldV.Concatenate(2, c.values)
+	}
+
+	return nn.NewKVHistory(histK, histV, logicalSlidingApplier{
+		b:      b,
+		K:      histK.Dim(2),
+		window: c.target.maxSize,
+		dtype:  keys.DType(),
+	})
+}
+
+func (c *speculativeRotatingKVCache) State() []*mlx.Array {
+	if c.keys == nil || c.values == nil {
+		return c.target.State()
+	}
+	oldK, oldV := c.target.logicalTail(c.target.maxSize - 1)
+	if oldK == nil || oldV == nil {
+		return []*mlx.Array{c.keys, c.values}
+	}
+	return []*mlx.Array{oldK.Concatenate(2, c.keys), oldV.Concatenate(2, c.values)}
+}
+
+func (c *speculativeRotatingKVCache) commit(n int) {
+	if c.keys == nil || c.values == nil || n <= 0 {
+		return
+	}
+	n = min(n, c.keys.Dim(2))
+	c.target.appendKV(prefixKV(c.keys, n), prefixKV(c.values, n))
+}
+
+type logicalSlidingApplier struct {
+	b      *batch.Batch
+	K      int
+	window int
+	dtype  mlx.DType
+}
+
+func (a logicalSlidingApplier) ApplyMask(logical nn.AttentionMask) nn.AttentionMask {
+	return logical.Intersect(nn.SlidingWindowMask(a.b, a.K, a.window, a.dtype))
+}
+
+func concatKV(prev, next *mlx.Array) *mlx.Array {
+	if prev == nil {
+		return next
+	}
+	return prev.Concatenate(2, next)
+}
+
+func prefixKV(a *mlx.Array, n int) *mlx.Array {
+	return a.Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(0, n), mlx.Slice())
+}
+
 // appendKV is the raw write path shared by Update and Restore —
 // routes to concat for prefill (L > 1) and update for decode.
 func (c *RotatingKVCache) appendKV(keys, values *mlx.Array) (*mlx.Array, *mlx.Array) {

x/mlxrunner/cache/rotating_attention_test.go

@@ -114,6 +114,61 @@ func TestRotatingKVCacheDecodeParity(t *testing.T) {
 	}
 }
 
+func TestAssistantSharedHistoryL1MasksMatchNoMask(t *testing.T) {
+	skipIfNoMLX(t)
+	if !mlx.MetalIsAvailable() {
+		t.Skip("MLX Metal not available")
+	}
+	const H, D = 1, 4
+	const window = 4
+	const total = 7
+	const scale = 1.0
+
+	q := mlx.FromValues([]float32{0.7, -0.4, 0.2, 0.9}, 1, H, 1, D)
+	mlx.Eval(q)
+
+	full := NewKVCache()
+	sliding := NewRotatingKVCache(window)
+	for pos := range total {
+		kVals := make([]float32, H*D)
+		vVals := make([]float32, H*D)
+		for i := range kVals {
+			kVals[i] = 0.1*float32(pos+1) + 0.01*float32(i)
+			vVals[i] = -0.1*float32(pos+1) + 0.01*float32(i)
+		}
+		k := mlx.FromValues(kVals, 1, H, 1, D)
+		v := mlx.FromValues(vVals, 1, H, 1, D)
+		full.Update(newKVBatch(full.Offset(), 1), k, v)
+		sliding.Update(newKVBatch(sliding.Offset(), 1), k, v)
+	}
+
+	b := newKVBatch(total-1, 1)
+	slidingHistory := sliding.View(b)
+	cases := []struct {
+		name string
+		h    *nn.KVHistory
+		mask nn.AttentionMask
+	}{
+		{name: "full", h: full.View(b), mask: nn.CausalMask()},
+		{name: "sliding", h: slidingHistory, mask: nn.CausalMask().Intersect(nn.SlidingWindowMask(b, slidingHistory.K().Dim(2), window, q.DType()))},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := nn.ScaledDotProductAttention(b, q, scale, nn.WithKVHistory(tc.h), nn.WithMask(tc.mask))
+			want := mlx.FastScaledDotProductAttention(q, tc.h.K(), tc.h.V(), scale, "", nil)
+
+			mlx.Eval(got, want)
+			gs, ws := got.Floats(), want.Floats()
+			for i := range ws {
+				if math.Abs(float64(gs[i]-ws[i])) > 1e-5 {
+					t.Fatalf("index %d: got %v, want %v", i, gs[i], ws[i])
+				}
+			}
+		})
+	}
+}
+
 // TestRotatingKVCachePrefillParity drives an L>1 prefill into a
 // rotating cache and verifies SDPA output through WithKVHistory
 // matches a reference computed from the same K/V with the model mask

x/mlxrunner/mlx/array_test.go

@@ -41,3 +41,36 @@ func TestFromValues(t *testing.T) {
 		}
 	})
 }
+
+func TestComparisonOpsAndBernoulli(t *testing.T) {
+	skipIfNoMLX(t)
+
+	a := FromValues([]float32{1, 2, 3}, 3)
+	b := FromValues([]float32{1, 1, 4}, 3)
+	eq := a.Equal(b).AsType(DTypeInt32)
+	gt := a.Greater(b).AsType(DTypeInt32)
+	le := a.LessEqual(b).AsType(DTypeInt32)
+	bern := Bernoulli(FromValues([]float32{1, 0}, 2)).AsType(DTypeInt32)
+	Eval(eq, gt, le, bern)
+
+	for name, tc := range map[string]struct {
+		got  []int
+		want []int
+	}{
+		"equal":     {eq.Ints(), []int{1, 0, 0}},
+		"greater":   {gt.Ints(), []int{0, 1, 0}},
+		"lessEqual": {le.Ints(), []int{1, 0, 1}},
+		"bernoulli": {bern.Ints(), []int{1, 0}},
+	} {
+		t.Run(name, func(t *testing.T) {
+			if len(tc.got) != len(tc.want) {
+				t.Fatalf("got %v, want %v", tc.got, tc.want)
+			}
+			for i := range tc.want {
+				if tc.got[i] != tc.want[i] {
+					t.Fatalf("got %v, want %v", tc.got, tc.want)
+				}
+			}
+		})
+	}
+}

x/mlxrunner/mlx/ops.go

@@ -137,12 +137,30 @@ func (t *Array) LogsumexpAxis(axis int, keepDims bool) *Array {
 	return out
 }
 
+func (t *Array) Equal(other *Array) *Array {
+	out := New("EQUAL")
+	C.mlx_equal(&out.ctx, t.ctx, other.ctx, DefaultStream().ctx)
+	return out
+}
+
+func (t *Array) Greater(other *Array) *Array {
+	out := New("GREATER")
+	C.mlx_greater(&out.ctx, t.ctx, other.ctx, DefaultStream().ctx)
+	return out
+}
+
 func (t *Array) Less(other *Array) *Array {
 	out := New("LESS")
 	C.mlx_less(&out.ctx, t.ctx, other.ctx, DefaultStream().ctx)
 	return out
 }
 
+func (t *Array) LessEqual(other *Array) *Array {
+	out := New("LESS_EQUAL")
+	C.mlx_less_equal(&out.ctx, t.ctx, other.ctx, DefaultStream().ctx)
+	return out
+}
+
 func (t *Array) MaxAxis(axis int, keepDims bool) *Array {
 	out := New("MAX_AXIS")
 	C.mlx_max_axis(&out.ctx, t.ctx, C.int(axis), C.bool(keepDims), DefaultStream().ctx)

x/mlxrunner/mlx/random.go

@@ -3,9 +3,24 @@ package mlx
 // #include "generated.h"
 import "C"
 
+import "unsafe"
+
 func (t *Array) Categorical(axis int) *Array {
 	key := New("")
 	out := New("")
 	C.mlx_random_categorical(&out.ctx, t.ctx, C.int(axis), key.ctx, DefaultStream().ctx)
 	return out
 }
+
+func Bernoulli(p *Array) *Array {
+	dims := p.Dims()
+	shape := make([]C.int, len(dims))
+	for i, d := range dims {
+		shape[i] = C.int(d)
+	}
+
+	key := New("")
+	out := New("BERNOULLI")
+	C.mlx_random_bernoulli(&out.ctx, p.ctx, unsafe.SliceData(shape), C.size_t(len(shape)), key.ctx, DefaultStream().ctx)
+	return out
+}

x/mlxrunner/model/base/base.go

@@ -27,9 +27,40 @@ type Model interface {
 	LoadWeights(tensors map[string]*mlx.Array) error
 }
 
+// DraftModel is an auxiliary model stored alongside a target model.
+type DraftModel interface {
+	LoadWeights(tensors map[string]*mlx.Array) error
+}
+
+// MTPDefaults holds model-provided draft-token defaults for speculative
+// decoding. Environment settings in the runner may override these values.
+type MTPDefaults struct {
+	InitialDraftTokens int
+	MaxDraftTokens     int
+	Enabled            bool
+}
+
+// MTPDefaultsProvider lets a model provide MTP policy defaults from its own
+// config without teaching the runner model-specific shape heuristics.
+type MTPDefaultsProvider interface {
+	MTPDraftDefaults(sample bool) MTPDefaults
+}
+
+// MTPDraftModel is a draft model capable of Gemma-style multi-token
+// prediction from target token embeddings, target hidden states, and target KV.
+type MTPDraftModel interface {
+	Draft(inputEmbeds *mlx.Array, position int32, caches []cache.Cache) (logits, hidden *mlx.Array)
+}
+
+// MTPEmbeddingModel exposes the target token embedding path used by MTP drafts.
+type MTPEmbeddingModel interface {
+	TokenEmbeddings(inputIDs *mlx.Array) *mlx.Array
+}
+
 var (
-	mu       sync.Mutex
+	mu            sync.Mutex
-	registry = make(map[string]func(root *model.Root) (Model, error))
+	registry      = make(map[string]func(root *model.Root) (Model, error))
+	draftRegistry = make(map[string]func(root *model.Root, target Model) (DraftModel, error))
 )
 
 // Register registers a model constructor by architecture name.
@@ -44,6 +75,17 @@ func Register(arch string, fn func(root *model.Root) (Model, error)) {
 	registry[arch] = fn
 }
 
+// RegisterDraft registers a draft model constructor by architecture name.
+func RegisterDraft(arch string, fn func(root *model.Root, target Model) (DraftModel, error)) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	if _, exists := draftRegistry[arch]; exists {
+		panic(fmt.Sprintf("draft model architecture %q already registered", arch))
+	}
+	draftRegistry[arch] = fn
+}
+
 // New reads config.json from the manifest, detects the architecture, looks up
 // the registered constructor, and calls it to create the model (with config
 // parsed and struct created, but weights not yet loaded).
@@ -78,6 +120,51 @@ func New(root *model.Root) (Model, error) {
 	return fn(root)
 }
 
+// NewDraft constructs the draft model described by the manifest config, if any.
+func NewDraft(root *model.Root, target Model) (DraftModel, error) {
+	if root == nil || root.Draft == nil {
+		return nil, nil
+	}
+
+	configPath := root.Draft.Config
+	if configPath == "" {
+		configPath = "draft/config.json"
+	}
+	configData, err := root.Manifest.ReadConfig(configPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read %s: %w", configPath, err)
+	}
+
+	var archConfig struct {
+		Architectures []string `json:"architectures"`
+		ModelType     string   `json:"model_type"`
+	}
+	if err := json.Unmarshal(configData, &archConfig); err != nil {
+		return nil, fmt.Errorf("failed to parse %s: %w", configPath, err)
+	}
+
+	arch := root.Draft.Architecture
+	if arch == "" && len(archConfig.Architectures) > 0 {
+		arch = archConfig.Architectures[0]
+	}
+	if arch == "" {
+		arch = archConfig.ModelType
+	}
+	if arch == "" {
+		return nil, fmt.Errorf("no draft architecture found in %s", configPath)
+	}
+	slog.Info("Draft model architecture", "arch", arch)
+
+	mu.Lock()
+	fn, ok := draftRegistry[arch]
+	mu.Unlock()
+	if !ok {
+		return nil, fmt.Errorf("unsupported draft architecture: %s", arch)
+	}
+
+	return fn(root, target)
+}
+
 // Weights returns a function that loads model weights, then pins all
 // arrays reachable from the model struct and sweeps everything else.
 func Weights(m Model) func(map[string]*mlx.Array) error {

x/mlxrunner/model/root.go

@@ -10,6 +10,7 @@ import (
 	"strconv"
 	"strings"
 
+	modeltypes "github.com/ollama/ollama/types/model"
 	"github.com/ollama/ollama/x/imagegen/manifest"
 )
 
@@ -22,6 +23,7 @@ type TensorQuantInfo struct {
 // Root wraps a ModelManifest with pre-scanned quantization metadata.
 type Root struct {
 	Manifest *manifest.ModelManifest
+	Draft    *modeltypes.Draft
 
 	// Backwards-compatible model-level quant metadata (first tensor blob).
 	quantType string
@@ -43,6 +45,7 @@ func Open(modelName string) (*Root, error) {
 		Manifest:    m,
 		tensorQuant: make(map[string]*TensorQuantInfo),
 	}
+	root.Draft = readDraftConfig(m)
 
 	for _, layer := range m.GetTensorLayers("") {
 		blobPath := m.BlobPath(layer.Digest)
@@ -68,6 +71,34 @@ func Open(modelName string) (*Root, error) {
 	return root, nil
 }
 
+func readDraftConfig(m *manifest.ModelManifest) *modeltypes.Draft {
+	if m == nil || m.Manifest == nil || m.Manifest.Config.Digest == "" {
+		return nil
+	}
+
+	data, err := os.ReadFile(m.BlobPath(m.Manifest.Config.Digest))
+	if err != nil {
+		return nil
+	}
+
+	var cfg modeltypes.ConfigV2
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return nil
+	}
+	if cfg.Draft != nil {
+		return cfg.Draft
+	}
+
+	if m.GetConfigLayer("draft/config.json") != nil {
+		return &modeltypes.Draft{
+			ModelFormat:  "safetensors",
+			TensorPrefix: "draft.",
+			Config:       "draft/config.json",
+		}
+	}
+	return nil
+}
+
 // Close is a no-op for now (future: release resources).
 func (r *Root) Close() {}
 

x/mlxrunner/mtp.go

@@ -0,0 +1,959 @@
+package mlxrunner
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"math"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/ollama/ollama/x/mlxrunner/batch"
+	"github.com/ollama/ollama/x/mlxrunner/cache"
+	"github.com/ollama/ollama/x/mlxrunner/mlx"
+	"github.com/ollama/ollama/x/mlxrunner/model/base"
+	sampler "github.com/ollama/ollama/x/mlxrunner/sample"
+)
+
+const (
+	mtpDefaultInitialDraftTokens = 4
+	mtpDefaultMaxDraftTokens     = 16
+)
+
+type mtpDraftSchedule string
+
+const (
+	mtpDraftScheduleHeuristic mtpDraftSchedule = "heuristic"
+	mtpDraftScheduleConstant  mtpDraftSchedule = "constant"
+)
+
+type mtpStats struct {
+	iterations            int
+	drafted               int
+	accepted              int
+	mismatches            int
+	allAccepted           int
+	batched               int
+	serial                int
+	compared              int
+	batchSerialMismatches int
+	maxDraft              int
+	targetDuration        time.Duration
+	draftDuration         time.Duration
+	validateDuration      time.Duration
+}
+
+type mtpOptions struct {
+	initialDraftTokens    int
+	maxDraftTokens        int
+	draftSchedule         mtpDraftSchedule
+	serialValidate        bool
+	compareSerialValidate bool
+}
+
+func (r *Runner) mtpDefaults(sample bool) base.MTPDefaults {
+	defaults := base.MTPDefaults{
+		InitialDraftTokens: mtpDefaultInitialDraftTokens,
+		MaxDraftTokens:     mtpDefaultMaxDraftTokens,
+		Enabled:            true,
+	}
+	if p, ok := r.Model.(base.MTPDefaultsProvider); ok {
+		defaults = p.MTPDraftDefaults(sample)
+	}
+	if defaults.InitialDraftTokens <= 0 {
+		defaults.InitialDraftTokens = mtpDefaultInitialDraftTokens
+	}
+	if defaults.MaxDraftTokens <= 0 {
+		defaults.MaxDraftTokens = mtpDefaultMaxDraftTokens
+	}
+	return defaults
+}
+
+func (r *Runner) loadMTPOptions(sample bool) mtpOptions {
+	defaults := r.mtpDefaults(sample)
+
+	opts := mtpOptions{
+		initialDraftTokens: defaults.InitialDraftTokens,
+		maxDraftTokens:     defaults.MaxDraftTokens,
+		draftSchedule:      mtpDraftScheduleConstant,
+	}
+	if v := positiveEnvInt("OLLAMA_MLX_MTP_MAX_DRAFT_TOKENS"); v > 0 {
+		opts.maxDraftTokens = v
+	}
+	if v := positiveEnvInt("OLLAMA_MLX_MTP_INITIAL_DRAFT_TOKENS"); v > 0 {
+		opts.initialDraftTokens = v
+	}
+	if opts.initialDraftTokens > opts.maxDraftTokens {
+		opts.initialDraftTokens = opts.maxDraftTokens
+	}
+	if b, err := strconv.ParseBool(os.Getenv("OLLAMA_MLX_MTP_SERIAL_VALIDATE")); err == nil {
+		opts.serialValidate = b
+	}
+	if b, err := strconv.ParseBool(os.Getenv("OLLAMA_MLX_MTP_COMPARE_SERIAL_VALIDATE")); err == nil {
+		opts.compareSerialValidate = b
+	}
+	switch schedule := strings.ToLower(strings.TrimSpace(os.Getenv("OLLAMA_MLX_MTP_DRAFT_SCHEDULE"))); schedule {
+	case "", string(mtpDraftScheduleConstant):
+		opts.draftSchedule = mtpDraftScheduleConstant
+	case string(mtpDraftScheduleHeuristic):
+		opts.draftSchedule = mtpDraftScheduleHeuristic
+	default:
+		slog.Warn("invalid MTP env setting", "key", "OLLAMA_MLX_MTP_DRAFT_SCHEDULE", "value", schedule)
+	}
+	return opts
+}
+
+func positiveEnvInt(key string) int {
+	raw := os.Getenv(key)
+	if raw == "" {
+		return 0
+	}
+	v, err := strconv.Atoi(raw)
+	if err != nil || v <= 0 {
+		slog.Warn("invalid MTP env setting", "key", key, "value", raw)
+		return 0
+	}
+	return v
+}
+
+func (r *Runner) useGreedyMTP(opts sampler.Options) bool {
+	if r.Draft == nil {
+		return false
+	}
+	if _, ok := r.Draft.(base.MTPDraftModel); !ok {
+		return false
+	}
+	if _, ok := r.Model.(base.MTPEmbeddingModel); !ok {
+		return false
+	}
+	if !r.mtpDefaults(false).Enabled {
+		return false
+	}
+	if opts.Logprobs || opts.TopLogprobs > 0 {
+		return false
+	}
+	if opts.Temperature != 0 {
+		return false
+	}
+	repeatPenaltyNeutral := opts.RepeatPenalty <= 0 || opts.RepeatPenalty == 1
+	topPNeutral := opts.TopP <= 0 || opts.TopP >= 1
+	topKNeutral := opts.TopK <= 0
+	return repeatPenaltyNeutral && opts.PresencePenalty == 0 && opts.FrequencyPenalty == 0 && topPNeutral && topKNeutral && opts.MinP == 0
+}
+
+func (r *Runner) useSampleMTP(opts sampler.Options) bool {
+	if serial, err := strconv.ParseBool(os.Getenv("OLLAMA_MLX_MTP_SERIAL_VALIDATE")); err == nil && serial {
+		return false
+	}
+	if compare, err := strconv.ParseBool(os.Getenv("OLLAMA_MLX_MTP_COMPARE_SERIAL_VALIDATE")); err == nil && compare {
+		return false
+	}
+	if r.Draft == nil {
+		return false
+	}
+	if _, ok := r.Draft.(base.MTPDraftModel); !ok {
+		return false
+	}
+	if _, ok := r.Model.(base.MTPEmbeddingModel); !ok {
+		return false
+	}
+	if !r.mtpDefaults(true).Enabled {
+		return false
+	}
+	if opts.Logprobs || opts.TopLogprobs > 0 {
+		return false
+	}
+	return opts.Temperature != 0
+}
+
+func (r *Runner) runGreedyMTPDecode(ctx context.Context, request Request, session *cacheSession, caches []cache.Cache, seed []int32, position *int, started time.Time) error {
+	targetEmbeddings := r.Model.(base.MTPEmbeddingModel)
+	draft := r.Draft.(base.MTPDraftModel)
+	mtpOpts := r.loadMTPOptions(false)
+	stats := mtpStats{maxDraft: mtpOpts.initialDraftTokens}
+	draftLimit := mtpOpts.initialDraftTokens
+	slog.Info("MTP greedy decode enabled", "initial_draft_tokens", mtpOpts.initialDraftTokens, "max_draft_tokens", mtpOpts.maxDraftTokens, "draft_schedule", mtpOpts.draftSchedule, "serial_validate", mtpOpts.serialValidate, "compare_serial_validate", mtpOpts.compareSerialValidate)
+
+	targetForward := func(token *mlx.Array) *mlx.Array {
+		fwd := r.Model.Forward(&batch.Batch{
+			InputIDs:     token,
+			SeqOffsets:   []int32{int32(*position)},
+			SeqQueryLens: []int32{int32(token.Dim(1))},
+		}, caches)
+		*position += token.Dim(1)
+		return fwd
+	}
+
+	hidden := targetForward(mlx.FromValues(seed, 1, len(seed)))
+	current := sampler.Result{Token: greedyTokenFromLogits(r.lastLogits(hidden))}
+	mlx.Pin(current.Arrays()...)
+	mlx.Sweep()
+	mlx.AsyncEval(current.Arrays()...)
+	defer func() {
+		mlx.Unpin(current.Arrays()...)
+	}()
+
+	dec := decoder{tokenizer: r.Tokenizer}
+	final := CompletionResponse{Done: true, PromptEvalCount: len(request.Tokens), DoneReason: 1}
+	now := started
+
+	generated := 0
+	for generated < request.Options.NumPredict {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+
+		t0 := time.Now()
+		hidden = targetForward(current.Token.ExpandDims(-1))
+		baseLogits := r.lastLogits(hidden)
+		stats.targetDuration += time.Since(t0)
+
+		if generated == 0 {
+			mlx.Eval(current.Arrays()...)
+			final.PromptEvalDuration = time.Since(now)
+			now = time.Now()
+		}
+
+		done, err := r.emitMTPToken(ctx, request, session, &dec, current, &final)
+		if err != nil {
+			return err
+		}
+		if !done {
+			generated++
+		}
+		if done || generated >= request.Options.NumPredict {
+			break
+		}
+
+		stats.iterations++
+		maxDraft := min(draftLimit, request.Options.NumPredict-generated)
+		t0 = time.Now()
+		draftTokens := r.generateMTPDrafts(draft, targetEmbeddings, current.Token, hidden, caches, int32(*position-1), maxDraft)
+		draftCount := 0
+		if draftTokens != nil {
+			draftCount = draftTokens.Dim(1)
+			mlx.Pin(baseLogits, draftTokens)
+			mlx.Eval(draftTokens)
+			mlx.Sweep()
+		}
+		stats.draftDuration += time.Since(t0)
+		stats.drafted += draftCount
+		var next sampler.Result
+		if draftCount == 0 {
+			next = sampler.Result{Token: greedyTokenFromLogits(baseLogits)}
+		} else {
+			var accepted int
+			t0 = time.Now()
+			next, accepted, done, err = r.acceptMTPDrafts(ctx, request, session, &dec, caches, position, baseLogits, draftTokens, &final, &generated, &stats, mtpOpts)
+			stats.validateDuration += time.Since(t0)
+			mlx.Unpin(baseLogits, draftTokens)
+			if err != nil {
+				return err
+			}
+			stats.accepted += accepted
+			switch {
+			case mtpOpts.draftSchedule == mtpDraftScheduleConstant:
+			case accepted == draftCount:
+				stats.allAccepted++
+				draftLimit = min(mtpOpts.maxDraftTokens, draftLimit+2)
+			default:
+				stats.mismatches++
+				draftLimit = max(1, draftLimit-1)
+			}
+			if mtpOpts.draftSchedule == mtpDraftScheduleConstant {
+				if accepted == draftCount {
+					stats.allAccepted++
+				} else {
+					stats.mismatches++
+				}
+			}
+			stats.maxDraft = max(stats.maxDraft, draftLimit)
+			if next.Token == nil {
+				mlx.Sweep()
+			}
+			if done || generated >= request.Options.NumPredict {
+				break
+			}
+		}
+
+		mlx.Pin(next.Arrays()...)
+		old := current
+		current = next
+		mlx.Unpin(old.Arrays()...)
+		mlx.Sweep()
+		mlx.AsyncEval(current.Arrays()...)
+
+		if generated%256 == 0 {
+			mlx.ClearCache()
+		}
+	}
+
+	final.EvalCount = generated
+	final.EvalDuration = time.Since(now)
+	acceptance := 0.0
+	if stats.drafted > 0 {
+		acceptance = float64(stats.accepted) / float64(stats.drafted)
+	}
+	avgDraft := 0.0
+	avgAccepted := 0.0
+	if stats.iterations > 0 {
+		avgDraft = float64(stats.drafted) / float64(stats.iterations)
+		avgAccepted = float64(stats.accepted) / float64(stats.iterations)
+	}
+	slog.Info("MTP decode stats", "generated", generated, "drafted", stats.drafted, "accepted", stats.accepted, "acceptance", acceptance, "iterations", stats.iterations, "avg_draft", avgDraft, "avg_accepted", avgAccepted, "batched", stats.batched, "serial", stats.serial, "compared", stats.compared, "batch_serial_mismatches", stats.batchSerialMismatches, "mismatches", stats.mismatches, "all_accepted", stats.allAccepted, "max_draft", stats.maxDraft, "draft_schedule", mtpOpts.draftSchedule, "target_duration", stats.targetDuration, "draft_duration", stats.draftDuration, "validate_duration", stats.validateDuration)
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case request.Responses <- final:
+		return nil
+	}
+}
+
+func (r *Runner) runSampleMTPDecode(ctx context.Context, request Request, session *cacheSession, caches []cache.Cache, seed []int32, position *int, started time.Time) error {
+	targetEmbeddings := r.Model.(base.MTPEmbeddingModel)
+	draft := r.Draft.(base.MTPDraftModel)
+	mtpOpts := r.loadMTPOptions(true)
+	stats := mtpStats{maxDraft: mtpOpts.initialDraftTokens}
+	draftLimit := mtpOpts.initialDraftTokens
+	slog.Info("MTP sample decode enabled", "initial_draft_tokens", mtpOpts.initialDraftTokens, "max_draft_tokens", mtpOpts.maxDraftTokens, "draft_schedule", mtpOpts.draftSchedule, "serial_validate", mtpOpts.serialValidate)
+
+	targetForward := func(token *mlx.Array) *mlx.Array {
+		fwd := r.Model.Forward(&batch.Batch{
+			InputIDs:     token,
+			SeqOffsets:   []int32{int32(*position)},
+			SeqQueryLens: []int32{int32(token.Dim(1))},
+		}, caches)
+		*position += token.Dim(1)
+		return fwd
+	}
+
+	hidden := targetForward(mlx.FromValues(seed, 1, len(seed)))
+	current := r.Sampler.Sample([]int{pipelineSlot}, r.lastLogits(hidden))
+	mlx.Pin(current.Arrays()...)
+	mlx.Sweep()
+	mlx.AsyncEval(current.Arrays()...)
+	defer func() {
+		mlx.Unpin(current.Arrays()...)
+	}()
+
+	dec := decoder{tokenizer: r.Tokenizer}
+	final := CompletionResponse{Done: true, PromptEvalCount: len(request.Tokens), DoneReason: 1}
+	now := started
+
+	generated := 0
+	for generated < request.Options.NumPredict {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+
+		t0 := time.Now()
+		hidden = targetForward(mtpTokenInput(current.Token))
+		baseLogits := r.lastLogits(hidden)
+		stats.targetDuration += time.Since(t0)
+
+		if generated == 0 {
+			mlx.Eval(current.Arrays()...)
+			final.PromptEvalDuration = time.Since(now)
+			now = time.Now()
+		}
+
+		done, err := r.emitMTPToken(ctx, request, session, &dec, current, &final)
+		if err != nil {
+			return err
+		}
+		if !done {
+			generated++
+		}
+		if done || generated >= request.Options.NumPredict {
+			break
+		}
+
+		stats.iterations++
+		maxDraft := min(draftLimit, request.Options.NumPredict-generated)
+		t0 = time.Now()
+		candidates := r.generateMTPDraftCandidates(draft, targetEmbeddings, current.Token, hidden, caches, int32(*position-1), maxDraft)
+		draftCount := 0
+		if candidates != nil {
+			draftCount = candidates.tokens.Dim(1)
+			mlx.Pin(baseLogits, candidates.tokens, candidates.logits)
+			mlx.Sweep()
+		}
+		stats.draftDuration += time.Since(t0)
+		stats.drafted += draftCount
+
+		var next sampler.Result
+		if draftCount == 0 {
+			next = r.Sampler.Sample([]int{pipelineSlot}, baseLogits)
+		} else {
+			var accepted int
+			t0 = time.Now()
+			next, accepted, done, err = r.acceptSampleMTPDrafts(ctx, request, session, &dec, caches, position, baseLogits, candidates, &final, &generated, &stats)
+			stats.validateDuration += time.Since(t0)
+			mlx.Unpin(baseLogits, candidates.tokens, candidates.logits)
+			if err != nil {
+				return err
+			}
+			stats.accepted += accepted
+			switch {
+			case mtpOpts.draftSchedule == mtpDraftScheduleConstant:
+			case accepted == draftCount:
+				stats.allAccepted++
+				draftLimit = min(mtpOpts.maxDraftTokens, draftLimit+2)
+			default:
+				stats.mismatches++
+				draftLimit = max(1, draftLimit-1)
+			}
+			if mtpOpts.draftSchedule == mtpDraftScheduleConstant {
+				if accepted == draftCount {
+					stats.allAccepted++
+				} else {
+					stats.mismatches++
+				}
+			}
+			stats.maxDraft = max(stats.maxDraft, draftLimit)
+			if next.Token == nil {
+				mlx.Sweep()
+			}
+			if done || generated >= request.Options.NumPredict {
+				break
+			}
+		}
+
+		mlx.Pin(next.Arrays()...)
+		old := current
+		current = next
+		mlx.Unpin(old.Arrays()...)
+		mlx.Sweep()
+		mlx.AsyncEval(current.Arrays()...)
+
+		if generated%256 == 0 {
+			mlx.ClearCache()
+		}
+	}
+
+	final.EvalCount = generated
+	final.EvalDuration = time.Since(now)
+	acceptance := 0.0
+	if stats.drafted > 0 {
+		acceptance = float64(stats.accepted) / float64(stats.drafted)
+	}
+	avgDraft := 0.0
+	avgAccepted := 0.0
+	if stats.iterations > 0 {
+		avgDraft = float64(stats.drafted) / float64(stats.iterations)
+		avgAccepted = float64(stats.accepted) / float64(stats.iterations)
+	}
+	slog.Info("MTP decode stats", "mode", "sample", "generated", generated, "drafted", stats.drafted, "accepted", stats.accepted, "acceptance", acceptance, "iterations", stats.iterations, "avg_draft", avgDraft, "avg_accepted", avgAccepted, "batched", stats.batched, "serial", stats.serial, "mismatches", stats.mismatches, "all_accepted", stats.allAccepted, "max_draft", stats.maxDraft, "draft_schedule", mtpOpts.draftSchedule, "target_duration", stats.targetDuration, "draft_duration", stats.draftDuration, "validate_duration", stats.validateDuration)
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case request.Responses <- final:
+		return nil
+	}
+}
+
+type mtpDraftCandidates struct {
+	tokens *mlx.Array
+	// logits are the processed proposal scores used to sample tokens.
+	logits *mlx.Array
+}
+
+func (r *Runner) generateMTPDrafts(draft base.MTPDraftModel, target base.MTPEmbeddingModel, token *mlx.Array, hidden *mlx.Array, caches []cache.Cache, position int32, maxDraft int) *mlx.Array {
+	if maxDraft <= 0 {
+		return nil
+	}
+
+	lastToken := token.ExpandDims(-1)
+	lastHidden := hidden
+	draftTokens := make([]*mlx.Array, 0, maxDraft)
+
+	// Gemma4 assistant MTP is trained as "single-position" drafting:
+	// keep the RoPE/cache position anchored at the last target-seen token
+	// while the proposed token and projected hidden state advance.
+	for range maxDraft {
+		tokenEmbedding := target.TokenEmbeddings(lastToken)
+		inputs := tokenEmbedding.Concatenate(-1, lastHidden)
+		logits, projected := draft.Draft(inputs, position, caches)
+		stepLogits := r.lastLogitsFromLogits(logits)
+		nextToken := greedyTokenFromLogits(stepLogits)
+
+		lastToken = nextToken.ExpandDims(-1)
+		lastHidden = projected
+		draftTokens = append(draftTokens, lastToken)
+	}
+	if len(draftTokens) == 0 {
+		return nil
+	}
+	return mlx.Concatenate(draftTokens, 1)
+}
+
+func (r *Runner) generateMTPDraftCandidates(draft base.MTPDraftModel, target base.MTPEmbeddingModel, token *mlx.Array, hidden *mlx.Array, caches []cache.Cache, position int32, maxDraft int) *mtpDraftCandidates {
+	if maxDraft <= 0 {
+		return nil
+	}
+
+	lastToken := mtpTokenInput(token)
+	lastHidden := hidden
+	draftTokens := make([]*mlx.Array, 0, maxDraft)
+	draftLogits := make([]*mlx.Array, 0, maxDraft)
+	var prefix *mlx.Array
+
+	// Gemma4 assistant MTP is trained as "single-position" drafting:
+	// keep the RoPE/cache position anchored at the last target-seen token
+	// while the proposed token and projected hidden state advance.
+	for range maxDraft {
+		tokenEmbedding := target.TokenEmbeddings(lastToken)
+		inputs := tokenEmbedding.Concatenate(-1, lastHidden)
+		logits, projected := draft.Draft(inputs, position, caches)
+		stepLogits := r.lastLogitsFromLogits(logits)
+		stepScores := r.Sampler.SpeculativeScores(pipelineSlot, stepLogits, prefix)
+		nextToken := stepScores.Categorical(-1).AsType(mlx.DTypeInt32)
+
+		lastToken = mtpTokenInput(nextToken)
+		lastHidden = projected
+		draftTokens = append(draftTokens, lastToken)
+		draftLogits = append(draftLogits, stepScores.ExpandDims(1))
+		if prefix == nil {
+			prefix = lastToken
+		} else {
+			prefix = prefix.Concatenate(1, lastToken)
+		}
+	}
+	if len(draftTokens) == 0 {
+		return nil
+	}
+	return &mtpDraftCandidates{
+		tokens: mlx.Concatenate(draftTokens, 1),
+		logits: mlx.Concatenate(draftLogits, 1),
+	}
+}
+
+func (r *Runner) acceptMTPDrafts(ctx context.Context, request Request, session *cacheSession, dec *decoder, caches []cache.Cache, position *int, baseLogits *mlx.Array, draftTokens *mlx.Array, final *CompletionResponse, generated *int, stats *mtpStats, opts mtpOptions) (sampler.Result, int, bool, error) {
+	if opts.serialValidate {
+		stats.serial++
+		return r.acceptMTPDraftsSerial(ctx, request, session, dec, caches, position, baseLogits, draftTokens, final, generated)
+	}
+
+	specCaches, spec, ok := cache.BeginSpeculation(caches)
+	if ok {
+		stats.batched++
+		return r.acceptMTPDraftsBatched(ctx, request, session, dec, caches, specCaches, spec, position, baseLogits, draftTokens, final, generated, stats, opts)
+	}
+
+	stats.serial++
+	return r.acceptMTPDraftsSerial(ctx, request, session, dec, caches, position, baseLogits, draftTokens, final, generated)
+}
+
+func (r *Runner) acceptMTPDraftsBatched(ctx context.Context, request Request, session *cacheSession, dec *decoder, liveCaches []cache.Cache, caches []cache.Cache, spec *cache.Speculation, position *int, baseLogits *mlx.Array, draftTokens *mlx.Array, final *CompletionResponse, generated *int, stats *mtpStats, opts mtpOptions) (sampler.Result, int, bool, error) {
+	before := *position
+	draftCount := draftTokens.Dim(1)
+	hiddenSeq := r.Model.Forward(&batch.Batch{
+		InputIDs:     draftTokens,
+		SeqOffsets:   []int32{int32(before)},
+		SeqQueryLens: []int32{int32(draftCount)},
+	}, caches)
+
+	accepted := 0
+	var next sampler.Result
+	done := false
+
+	selectedTokens := r.mtpValidationTokens(baseLogits, hiddenSeq)
+	mlx.Eval(draftTokens, selectedTokens)
+	draftIDs := draftTokens.Ints()
+	selectedIDs := selectedTokens.Ints()
+	if len(selectedIDs) < draftCount+1 {
+		return sampler.Result{}, accepted, false, fmt.Errorf("mtp validation produced %d tokens for %d draft tokens", len(selectedIDs), draftCount)
+	}
+
+	for i, id := range draftIDs {
+		if selectedIDs[i] != id {
+			next = sampler.Result{Token: mtpTokenAt(selectedTokens, i)}
+			break
+		}
+		accepted++
+		if r.Tokenizer.IsEOS(int32(id)) {
+			done = true
+			break
+		}
+	}
+
+	if opts.compareSerialValidate {
+		spec.Commit(0)
+		r.compareMTPBatchedWithSerial(ctx, liveCaches, before, baseLogits, hiddenSeq, draftIDs, selectedIDs, accepted, draftCount, stats)
+	}
+	spec.Commit(accepted)
+	*position = before + accepted
+
+	for _, id := range draftIDs[:accepted] {
+		if *generated >= request.Options.NumPredict {
+			done = true
+			break
+		}
+		res := sampler.Result{Token: mlx.FromValues([]int32{int32(id)}, 1)}
+		var err error
+		done, err = r.emitMTPToken(ctx, request, session, dec, res, final)
+		if err != nil {
+			return sampler.Result{}, accepted, done, err
+		}
+		if !done {
+			(*generated)++
+		}
+		if done {
+			break
+		}
+	}
+
+	if done || *generated >= request.Options.NumPredict {
+		return sampler.Result{}, accepted, true, nil
+	}
+	if next.Token == nil {
+		next = sampler.Result{Token: mtpTokenAt(selectedTokens, draftCount)}
+	}
+	return next, accepted, false, nil
+}
+
+func (r *Runner) acceptSampleMTPDrafts(ctx context.Context, request Request, session *cacheSession, dec *decoder, caches []cache.Cache, position *int, baseLogits *mlx.Array, candidates *mtpDraftCandidates, final *CompletionResponse, generated *int, stats *mtpStats) (sampler.Result, int, bool, error) {
+	specCaches, spec, ok := cache.BeginSpeculation(caches)
+	if !ok {
+		stats.serial++
+		return r.Sampler.Sample([]int{pipelineSlot}, baseLogits), 0, false, nil
+	}
+	stats.batched++
+
+	before := *position
+	draftCount := candidates.tokens.Dim(1)
+	hiddenSeq := r.Model.Forward(&batch.Batch{
+		InputIDs:     candidates.tokens,
+		SeqOffsets:   []int32{int32(before)},
+		SeqQueryLens: []int32{int32(draftCount)},
+	}, specCaches)
+
+	targetScores := r.Sampler.SpeculativeScores(pipelineSlot, r.mtpValidationLogits(baseLogits, hiddenSeq), candidates.tokens)
+	draftScores := candidates.logits
+	if draftScores.NumDims() == 3 {
+		draftScores = draftScores.Squeeze(0)
+	}
+	acceptedMask := mtpSampleAcceptedMask(targetScores, draftScores, candidates.tokens, draftCount)
+	mlx.Eval(candidates.tokens, acceptedMask)
+
+	draftIDs := candidates.tokens.Ints()
+	acceptedFlags := acceptedMask.Ints()
+	accepted := 0
+	for _, ok := range acceptedFlags {
+		if ok == 0 {
+			break
+		}
+		accepted++
+	}
+	if accepted > draftCount {
+		return sampler.Result{}, 0, false, fmt.Errorf("mtp sample validation accepted %d tokens for %d draft tokens", accepted, draftCount)
+	}
+
+	commitIDs := make([]int32, 0, accepted+1)
+	done := false
+	for i, id := range draftIDs[:accepted] {
+		commitIDs = append(commitIDs, int32(id))
+		if r.Tokenizer.IsEOS(int32(id)) {
+			done = true
+			accepted = i + 1
+			commitIDs = commitIDs[:accepted]
+			break
+		}
+	}
+
+	spec.Commit(accepted)
+	*position = before + accepted
+
+	for _, id := range draftIDs[:accepted] {
+		if *generated >= request.Options.NumPredict {
+			done = true
+			break
+		}
+		res := sampler.Result{Token: mlx.FromValues([]int32{int32(id)}, 1)}
+		var err error
+		done, err = r.emitMTPToken(ctx, request, session, dec, res, final)
+		if err != nil {
+			return sampler.Result{}, accepted, done, err
+		}
+		if !done {
+			(*generated)++
+		}
+		if done {
+			break
+		}
+	}
+
+	if done || *generated >= request.Options.NumPredict {
+		r.Sampler.Commit(pipelineSlot, commitIDs)
+		return sampler.Result{}, accepted, true, nil
+	}
+
+	var nextToken *mlx.Array
+	if accepted == draftCount {
+		nextToken = mtpSampleTokenAt(targetScores, draftCount)
+	} else {
+		nextToken = mtpSampleResidualToken(targetScores, draftScores, accepted)
+	}
+	mlx.Eval(nextToken)
+	nextID := int32(tokenID(nextToken))
+	commitIDs = append(commitIDs, nextID)
+	r.Sampler.Commit(pipelineSlot, commitIDs)
+
+	return sampler.Result{Token: nextToken}, accepted, false, nil
+}
+
+func mtpSampleAcceptedMask(targetScores, draftScores, draftTokens *mlx.Array, draftCount int) *mlx.Array {
+	targetProbs := mlx.SoftmaxAxis(targetScores.Slice(mlx.Slice(0, draftCount), mlx.Slice()), -1, true)
+	draftProbs := mlx.SoftmaxAxis(draftScores, -1, true)
+	if draftTokens.NumDims() == 2 {
+		draftTokens = draftTokens.Squeeze(0)
+	}
+	indices := draftTokens.ExpandDims(-1)
+	p := targetProbs.TakeAlongAxis(indices, -1).Squeeze(-1)
+	q := draftProbs.TakeAlongAxis(indices, -1).Squeeze(-1)
+	acceptP := mlx.Minimum(p.Divide(q), mlx.FromValue(float32(1)))
+	return mlx.Bernoulli(acceptP).AsType(mlx.DTypeInt32)
+}
+
+func mtpSampleTokenAt(scores *mlx.Array, index int) *mlx.Array {
+	row := scores.Slice(mlx.Slice(index, index+1), mlx.Slice())
+	return mtpTokenVector(row.Categorical(-1).AsType(mlx.DTypeInt32))
+}
+
+func mtpSampleResidualToken(targetScores, draftScores *mlx.Array, index int) *mlx.Array {
+	p := mlx.SoftmaxAxis(targetScores.Slice(mlx.Slice(index, index+1), mlx.Slice()), -1, true)
+	q := mlx.SoftmaxAxis(draftScores.Slice(mlx.Slice(index, index+1), mlx.Slice()), -1, true)
+	diff := p.Subtract(q)
+	positive := mlx.Maximum(diff, mlx.FromValue(float32(1e-20)))
+	logits := mlx.Log(positive)
+	logits = mlx.Where(diff.LessEqual(mlx.FromValue(float32(0))), mlx.FromValue(float32(math.Inf(-1))), logits)
+	return mtpTokenVector(logits.Categorical(-1).AsType(mlx.DTypeInt32))
+}
+
+func mtpTokenInput(token *mlx.Array) *mlx.Array {
+	switch token.NumDims() {
+	case 0:
+		return token.Reshape(1, 1)
+	case 1:
+		return token.ExpandDims(-1)
+	case 2:
+		return token
+	default:
+		panic(fmt.Sprintf("mtp token must be rank 0, 1, or 2, got rank %d", token.NumDims()))
+	}
+}
+
+func mtpTokenVector(token *mlx.Array) *mlx.Array {
+	switch token.NumDims() {
+	case 0:
+		return token.Reshape(1)
+	case 1:
+		return token
+	default:
+		panic(fmt.Sprintf("mtp sampled token must be rank 0 or 1, got rank %d", token.NumDims()))
+	}
+}
+
+func (r *Runner) compareMTPBatchedWithSerial(ctx context.Context, caches []cache.Cache, before int, baseLogits, hiddenSeq *mlx.Array, draftIDs, selectedIDs []int, accepted, draftCount int, stats *mtpStats) {
+	serialCaches, ok := cache.BeginIsolatedSpeculation(caches)
+	if !ok {
+		return
+	}
+
+	compareCount := accepted + 1
+	if accepted == draftCount {
+		// Include the target bonus token when every draft was accepted.
+		compareCount = draftCount + 1
+	}
+
+	serialLogits := baseLogits
+	for i := range compareCount {
+		if err := ctx.Err(); err != nil {
+			return
+		}
+		if i >= len(selectedIDs) {
+			return
+		}
+
+		batchedLogits := baseLogits
+		if i > 0 {
+			batchedLogits = r.targetLogitsAt(hiddenSeq, i-1)
+		}
+
+		batchedToken := greedyTokenFromLogits(batchedLogits)
+		serialToken := greedyTokenFromLogits(serialLogits)
+		mlx.Eval(batchedToken, serialToken)
+
+		batchedID := tokenID(batchedToken)
+		vectorizedID := selectedIDs[i]
+		serialID := tokenID(serialToken)
+		stats.compared++
+		if vectorizedID != serialID {
+			firstMismatch := stats.batchSerialMismatches == 0
+			stats.batchSerialMismatches++
+			if !firstMismatch {
+				return
+			}
+
+			draftID := -1
+			if i < draftCount {
+				draftID = draftIDs[i]
+			}
+			batchedTop := top2FromLogits(batchedLogits)
+			serialTop := top2FromLogits(serialLogits)
+			slog.Warn("MTP batched validation differs from serial validation",
+				"position", before+i,
+				"draft", draftID,
+				"batched", vectorizedID,
+				"batched_slice", batchedID,
+				"serial", serialID,
+				"batched_slice_top1", batchedTop.firstToken,
+				"batched_slice_top2", batchedTop.secondToken,
+				"batched_slice_margin", batchedTop.margin,
+				"serial_top1", serialTop.firstToken,
+				"serial_top2", serialTop.secondToken,
+				"serial_margin", serialTop.margin,
+			)
+			return
+		}
+
+		if i >= draftCount || i >= accepted {
+			return
+		}
+
+		hidden := r.Model.Forward(&batch.Batch{
+			InputIDs:     mlx.FromValues([]int32{int32(draftIDs[i])}, 1, 1),
+			SeqOffsets:   []int32{int32(before + i)},
+			SeqQueryLens: []int32{1},
+		}, serialCaches)
+		serialLogits = r.lastLogits(hidden)
+	}
+}
+
+type mtpTop2 struct {
+	firstToken  int
+	secondToken int
+	margin      float64
+}
+
+func top2FromLogits(logits *mlx.Array) mtpTop2 {
+	indices := logits.Negative().ArgsortAxis(-1).Slice(mlx.Slice(), mlx.Slice(0, 2))
+	indices32 := indices.AsType(mlx.DTypeInt32)
+	values := logits.TakeAlongAxis(indices, -1).AsType(mlx.DTypeFloat32)
+	mlx.Eval(indices32, values)
+
+	tokenIDs := indices32.Ints()
+	logitValues := values.Floats()
+	if len(tokenIDs) < 2 || len(logitValues) < 2 {
+		return mtpTop2{}
+	}
+	return mtpTop2{
+		firstToken:  tokenIDs[0],
+		secondToken: tokenIDs[1],
+		margin:      float64(logitValues[0] - logitValues[1]),
+	}
+}
+
+func (r *Runner) acceptMTPDraftsSerial(ctx context.Context, request Request, session *cacheSession, dec *decoder, caches []cache.Cache, position *int, baseLogits *mlx.Array, draftTokens *mlx.Array, final *CompletionResponse, generated *int) (sampler.Result, int, bool, error) {
+	logits := baseLogits
+	accepted := 0
+	draftIDs := draftTokens.Ints()
+
+	for _, id := range draftIDs {
+		selected := greedyTokenFromLogits(logits)
+		mlx.Eval(selected)
+		selectedID := tokenID(selected)
+		if selectedID != id {
+			return sampler.Result{Token: mlx.FromValues([]int32{int32(selectedID)}, 1)}, accepted, false, nil
+		}
+
+		hidden := r.Model.Forward(&batch.Batch{
+			InputIDs:     mlx.FromValues([]int32{int32(id)}, 1, 1),
+			SeqOffsets:   []int32{int32(*position)},
+			SeqQueryLens: []int32{1},
+		}, caches)
+		(*position)++
+		accepted++
+
+		res := sampler.Result{Token: mlx.FromValues([]int32{int32(id)}, 1)}
+		done, err := r.emitMTPToken(ctx, request, session, dec, res, final)
+		if err != nil {
+			return sampler.Result{}, accepted, done, err
+		}
+		if !done {
+			(*generated)++
+		}
+		if done || *generated >= request.Options.NumPredict {
+			return sampler.Result{}, accepted, true, nil
+		}
+
+		logits = r.lastLogits(hidden)
+	}
+
+	return sampler.Result{Token: greedyTokenFromLogits(logits)}, accepted, false, nil
+}
+
+func (r *Runner) emitMTPToken(ctx context.Context, request Request, session *cacheSession, dec *decoder, res sampler.Result, final *CompletionResponse) (bool, error) {
+	output := int32(tokenID(res.Token))
+	session.outputs = append(session.outputs, output)
+
+	if r.Tokenizer.IsEOS(output) {
+		final.DoneReason = 0
+		return true, nil
+	}
+
+	if resp, ok := dec.decode(res); ok {
+		select {
+		case <-ctx.Done():
+			return false, ctx.Err()
+		case request.Responses <- resp:
+		}
+	}
+	return false, nil
+}
+
+func (r *Runner) lastLogits(hidden *mlx.Array) *mlx.Array {
+	logits := r.Model.Unembed(hidden)
+	return r.lastLogitsFromLogits(logits)
+}
+
+func (r *Runner) targetLogitsAt(hiddenSeq *mlx.Array, index int) *mlx.Array {
+	hidden := hiddenSeq.Slice(mlx.Slice(), mlx.Slice(index), mlx.Slice())
+	return r.lastLogits(hidden)
+}
+
+func (r *Runner) mtpValidationTokens(baseLogits, hiddenSeq *mlx.Array) *mlx.Array {
+	return greedyTokenFromLogits(r.mtpValidationLogits(baseLogits, hiddenSeq))
+}
+
+func (r *Runner) mtpValidationLogits(baseLogits, hiddenSeq *mlx.Array) *mlx.Array {
+	seqLogits := r.Model.Unembed(hiddenSeq)
+	return baseLogits.ExpandDims(1).Concatenate(1, seqLogits)
+}
+
+func mtpTokenAt(tokens *mlx.Array, index int) *mlx.Array {
+	return tokens.Slice(mlx.Slice(), mlx.Slice(index)).Squeeze(0)
+}
+
+func (r *Runner) lastLogitsFromLogits(logits *mlx.Array) *mlx.Array {
+	return logits.Slice(mlx.Slice(), mlx.Slice(logits.Dim(1)-1), mlx.Slice()).Squeeze(1)
+}
+
+func greedyTokenFromLogits(logits *mlx.Array) *mlx.Array {
+	return logits.Argmax(-1, false).AsType(mlx.DTypeInt32)
+}
+
+func tokenID(token *mlx.Array) int {
+	if token == nil {
+		return -1
+	}
+	if token.DType() == mlx.DTypeInt32 {
+		ids := token.Ints()
+		if len(ids) > 0 {
+			return ids[0]
+		}
+	}
+	return token.Int()
+}

x/mlxrunner/pipeline.go

@@ -146,6 +146,12 @@ func (r *Runner) TextGenerationPipeline(ctx context.Context, request Request) er
 
 	// Register the sampler after prefill completes.
 	r.Sampler.Add(pipelineSlot, request.SamplerOpts, inputs)
+	if r.useGreedyMTP(request.SamplerOpts) {
+		return r.runGreedyMTPDecode(ctx, request, session, caches, tokens[processed:], &position, now)
+	}
+	if r.useSampleMTP(request.SamplerOpts) {
+		return r.runSampleMTPDecode(ctx, request, session, caches, tokens[processed:], &position, now)
+	}
 
 	step := func(token *mlx.Array) sampler.Result {
 		fwd := r.Model.Forward(&batch.Batch{

x/mlxrunner/runner.go

@@ -35,6 +35,7 @@ type Request struct {
 
 type Runner struct {
 	Model         base.Model
+	Draft         base.DraftModel
 	Tokenizer     *tokenizer.Tokenizer
 	Requests      chan Request
 	Sampler       *sample.Sampler
@@ -61,12 +62,41 @@ func (r *Runner) Load(modelName string) error {
 		return err
 	}
 
-	// Assign weights to model (model-specific logic)
+	// Assign weights to model (model-specific logic). Target and draft weights
-	loadWeights := base.Weights(m)
+	// must be loaded before sweeping so tensors from a combined manifest are
-	if err := loadWeights(tensors); err != nil {
+	// not discarded before the draft model can retain them.
+	if err := m.LoadWeights(tensors); err != nil {
 		return err
 	}
 
+	r.Draft = nil
+	draft, err := base.NewDraft(root, m)
+	if err != nil {
+		return err
+	}
+	if draft != nil {
+		if err := draft.LoadWeights(tensors); err != nil {
+			return err
+		}
+		r.Draft = draft
+	}
+
+	collected := mlx.Collect(m)
+	if draft != nil {
+		draftArrays := mlx.Collect(draft)
+		collected = append(collected, draftArrays...)
+		if root.Draft != nil {
+			slog.Info("Loaded draft model", "tensor_prefix", root.Draft.TensorPrefix, "config", root.Draft.Config, "arrays", len(draftArrays))
+		} else {
+			slog.Info("Loaded draft model", "arrays", len(draftArrays))
+		}
+	}
+	for _, arr := range collected {
+		mlx.Pin(arr)
+	}
+	mlx.Sweep()
+	mlx.Eval(collected...)
+
 	r.Model = m
 	r.Tokenizer = m.Tokenizer()
 	r.contextLength = m.MaxContextLength()

x/mlxrunner/sample/sample.go

@@ -349,6 +349,159 @@ func (s *Sampler) Sample(seqIDs []int, logits *mlx.Array) Result {
 	return res
 }
 
+// SpeculativeScores applies this slot's non-sampling transforms to logits
+// without mutating sampler state. Row i is scored as if draftTokens[:i] had
+// already been appended to the slot history. logits must be [R,V] or [1,R,V].
+func (s *Sampler) SpeculativeScores(seqID int, logits *mlx.Array, draftTokens *mlx.Array) *mlx.Array {
+	slot, ok := s.byID[seqID]
+	if !ok {
+		panic(fmt.Sprintf("sample.Sampler.SpeculativeScores: seqID %d not registered", seqID))
+	}
+
+	if logits.NumDims() == 3 {
+		if logits.Dim(0) != 1 {
+			panic("sample.Sampler.SpeculativeScores: only batch size 1 is supported")
+		}
+		logits = logits.Squeeze(0)
+	}
+	if logits.NumDims() != 2 {
+		panic(fmt.Sprintf("sample.Sampler.SpeculativeScores: logits must be rank 2 or 3, got rank %d", logits.NumDims()))
+	}
+
+	if draftTokens != nil && draftTokens.NumDims() == 1 {
+		draftTokens = draftTokens.ExpandDims(0)
+	}
+	rows := logits.Dim(0)
+	var hist *mlx.Array
+	if slot.opts.usesHistory() {
+		if s.history == nil {
+			panic(fmt.Sprintf("sample.Sampler.SpeculativeScores: seqID %d has no history", seqID))
+		}
+		if slot.historyLen < slot.opts.RepeatLastN {
+			return s.speculativeScoresSerial(slot, logits, draftTokens)
+		}
+		hist = s.speculativeHistory(slot, draftTokens, rows)
+	}
+
+	return slot.speculativeScores(&slotCtx{opts: slot.opts, history: hist}, logits)
+}
+
+// Commit appends already-selected tokens to seqID's repeat-penalty history.
+// It is used after speculative sampling once the accepted continuation is
+// known. Normal Sample calls continue to mutate history themselves.
+func (s *Sampler) Commit(seqID int, tokens []int32) {
+	if len(tokens) == 0 {
+		return
+	}
+	slot, ok := s.byID[seqID]
+	if !ok {
+		panic(fmt.Sprintf("sample.Sampler.Commit: seqID %d not registered", seqID))
+	}
+	if !slot.opts.usesHistory() {
+		return
+	}
+	if s.history == nil {
+		panic(fmt.Sprintf("sample.Sampler.Commit: seqID %d has no history", seqID))
+	}
+
+	row := slices.Index(s.slots, slot)
+	width := s.historyWidth()
+	take := min(len(tokens), slot.opts.RepeatLastN)
+	startLen := slot.historyLen + len(tokens) - take
+	writeTokens := tokens[len(tokens)-take:]
+	flatOffsets := make([]int32, take)
+	for i := range take {
+		ringPos := (startLen + i) % slot.opts.RepeatLastN
+		flatOffsets[i] = int32(row*width + ringPos)
+	}
+
+	flatIdx := mlx.NewArrayInt32(flatOffsets, []int32{int32(take), 1})
+	values := mlx.NewArrayInt32(writeTokens, []int32{int32(take), 1})
+	flatHist := s.history.Reshape(s.history.Dim(0)*width, 1)
+	s.history.Set(flatHist.PutAlongAxis(flatIdx, values, 0).Reshape(s.history.Dim(0), width))
+	slot.historyLen += len(tokens)
+}
+
+func (s *Sampler) speculativeScoresSerial(slot *slotState, logits *mlx.Array, draftTokens *mlx.Array) *mlx.Array {
+	rows := logits.Dim(0)
+	draftCount := 0
+	if draftTokens != nil {
+		draftCount = draftTokens.Dim(1)
+	}
+	row := slices.Index(s.slots, slot)
+	baseFill := min(slot.historyLen, slot.opts.RepeatLastN)
+	var base *mlx.Array
+	if baseFill > 0 {
+		base = s.history.Slice(mlx.Slice(row, row+1), mlx.Slice(0, baseFill))
+	}
+
+	scored := make([]*mlx.Array, 0, rows)
+	for i := range rows {
+		rowLogits := logits.Slice(mlx.Slice(i, i+1), mlx.Slice())
+		hist := base
+		prefixLen := min(i, draftCount)
+		if prefixLen > 0 {
+			prefix := draftTokens.Slice(mlx.Slice(), mlx.Slice(0, prefixLen))
+			if hist == nil {
+				hist = prefix
+			} else {
+				hist = hist.Concatenate(1, prefix)
+			}
+			if hist.Dim(1) > slot.opts.RepeatLastN {
+				hist = hist.Slice(mlx.Slice(), mlx.Slice(hist.Dim(1)-slot.opts.RepeatLastN, mlx.End))
+			}
+		}
+		scored = append(scored, slot.speculativeScores(&slotCtx{opts: slot.opts, history: hist}, rowLogits))
+	}
+	return mlx.Concatenate(scored, 0)
+}
+
+func (s *Sampler) speculativeHistory(slot *slotState, draftTokens *mlx.Array, rows int) *mlx.Array {
+	row := slices.Index(s.slots, slot)
+	width := slot.opts.RepeatLastN
+	base := s.history.Slice(mlx.Slice(row, row+1), mlx.Slice(0, width))
+	base = mlx.Tile(base, []int32{int32(rows), 1})
+	next := slot.historyLen % width
+	draftCount := 0
+	if draftTokens != nil {
+		draftCount = draftTokens.Dim(1)
+	}
+	if draftCount == 0 {
+		return base
+	}
+
+	sourceIdx := make([]int32, rows*width)
+	writeMask := make([]bool, rows*width)
+	for i := range rows {
+		prefixLen := min(i, draftCount)
+		for j := range prefixLen {
+			pos := (next + j) % width
+			sourceIdx[i*width+pos] = int32(j)
+			writeMask[i*width+pos] = true
+		}
+	}
+
+	draftRows := mlx.Tile(draftTokens, []int32{int32(rows), 1})
+	idx := mlx.NewArrayInt32(sourceIdx, []int32{int32(rows), int32(width)})
+	mask := mlx.FromValues(writeMask, rows, width)
+	values := draftRows.TakeAlongAxis(idx, 1)
+	return mlx.Where(mask, values, base)
+}
+
+func (slot *slotState) speculativeScores(ctx *slotCtx, logits *mlx.Array) *mlx.Array {
+	scores := logits
+	// buildTransforms always appends the final selector transform
+	// (greedy or temperature sampling). Speculative validation needs the
+	// processed logits before that selector mutates the distribution.
+	for _, t := range slot.transforms[:len(slot.transforms)-1] {
+		scores = t(ctx, scores)
+	}
+	if slot.opts.Temperature > 0 {
+		scores = mlx.DivScalar(scores, slot.opts.Temperature)
+	}
+	return scores
+}
+
 // canBatch reports whether the call can take the uniform batched path.
 // All slots must share Options; when penalties are active the call must
 // additionally cover every registered slot in registration order with a

x/mlxrunner/sample/sample_test.go

@@ -176,6 +176,65 @@ func TestSampleHistoryWindow(t *testing.T) {
 	}
 }
 
+func TestSpeculativeScoresUsesDraftHistoryWithoutCommit(t *testing.T) {
+	skipIfNoMLX(t)
+
+	s := New(128)
+	t.Cleanup(func() {
+		s.Free()
+		mlx.Sweep()
+	})
+
+	s.Add(0, Options{RepeatLastN: 2, RepeatPenalty: 10}, []int32{1, 2})
+	draftTokens := mlx.NewArrayInt32([]int32{3, 4}, []int32{1, 2})
+	scores := s.SpeculativeScores(0, batchLogits(
+		[]float32{0, 9, 9, 8, 0}, // history {1,2}; token 3 wins
+		[]float32{0, 0, 9, 9, 8}, // history {2,3}; token 4 wins
+		[]float32{0, 0, 9, 9, 8}, // history {3,4}; token 2 wins
+	), draftTokens)
+	tokens := scores.Argmax(-1, false).AsType(mlx.DTypeInt32)
+	mlx.Eval(tokens)
+
+	if got, want := tokens.Ints(), []int{3, 4, 2}; len(got) != len(want) {
+		t.Fatalf("tokens = %v, want %v", got, want)
+	} else {
+		for i := range want {
+			if got[i] != want[i] {
+				t.Fatalf("tokens = %v, want %v", got, want)
+			}
+		}
+	}
+	if s.byID[0].historyLen != 2 {
+		t.Fatalf("historyLen = %d, want 2", s.byID[0].historyLen)
+	}
+}
+
+func TestCommitBatchesRingWrites(t *testing.T) {
+	skipIfNoMLX(t)
+
+	s := New(128)
+	t.Cleanup(func() {
+		s.Free()
+		mlx.Sweep()
+	})
+
+	s.Add(0, Options{RepeatLastN: 4, RepeatPenalty: 1.1}, []int32{10, 11, 12})
+	s.Commit(0, []int32{20, 21, 22})
+	s.Commit(0, []int32{30, 31, 32, 33, 34})
+	mlx.Eval(s.history)
+
+	got := s.history.Ints()
+	want := []int{32, 33, 34, 31}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("history = %v, want %v", got, want)
+		}
+	}
+	if s.byID[0].historyLen != 11 {
+		t.Fatalf("historyLen = %d, want 11", s.byID[0].historyLen)
+	}
+}
+
 // TestBatchSamplingPreservesPerSlotBehavior is the core equivalence test:
 // for every representative dispatch branch (uniform, serial on mixed opts,
 // serial on partial ring, subset/out-of-order), a batched Sample call must

x/models/gemma4/assistant.go

@@ -0,0 +1,390 @@
+package gemma4
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/ollama/ollama/x/mlxrunner/batch"
+	"github.com/ollama/ollama/x/mlxrunner/cache"
+	"github.com/ollama/ollama/x/mlxrunner/mlx"
+	"github.com/ollama/ollama/x/mlxrunner/model"
+	"github.com/ollama/ollama/x/mlxrunner/model/base"
+	"github.com/ollama/ollama/x/models/nn"
+)
+
+var (
+	_ base.DraftModel    = (*AssistantModel)(nil)
+	_ base.MTPDraftModel = (*AssistantModel)(nil)
+)
+
+type AssistantConfig struct {
+	TextConfig               TextConfig `json:"text_config"`
+	BackboneHiddenSize       int32      `json:"backbone_hidden_size"`
+	UseOrderedEmbeddings     bool       `json:"use_ordered_embeddings"`
+	NumCentroids             int32      `json:"num_centroids"`
+	CentroidIntermediateTopK int32      `json:"centroid_intermediate_top_k"`
+}
+
+type AssistantModel struct {
+	PreProjection  nn.LinearLayer
+	PostProjection nn.LinearLayer
+	EmbedTokens    nn.EmbeddingLayer
+	LMHead         nn.LinearLayer
+	Centroids      nn.LinearLayer
+	TokenOrdering  *mlx.Array
+	Layers         []*AssistantLayer
+	Norm           *nn.RMSNorm
+
+	NormScaled *mlx.Array
+
+	*AssistantConfig
+	tensorPrefix string
+
+	QuantGroupSize int
+	QuantBits      int
+	QuantMode      string
+	TensorQuant    map[string]*model.TensorQuantInfo
+}
+
+type AssistantLayer struct {
+	InputNorm    *nn.RMSNorm
+	PostAttnNorm *nn.RMSNorm
+	PreFFNorm    *nn.RMSNorm
+	PostFFNorm   *nn.RMSNorm
+
+	InputNormScaled    *mlx.Array
+	PostAttnNormScaled *mlx.Array
+	PreFFNormScaled    *mlx.Array
+	PostFFNormScaled   *mlx.Array
+
+	Attention   *AssistantAttention
+	MLP         *MLP
+	LayerScalar *mlx.Array
+	IsSliding   bool
+}
+
+type AssistantAttention struct {
+	QProj nn.LinearLayer
+	OProj nn.LinearLayer
+	QNorm *nn.RMSNorm
+
+	QNormScaled *mlx.Array
+}
+
+func parseAssistantConfig(configData []byte) (AssistantConfig, error) {
+	var raw struct {
+		TextConfig json.RawMessage `json:"text_config"`
+
+		BackboneHiddenSize       int32 `json:"backbone_hidden_size"`
+		UseOrderedEmbeddings     bool  `json:"use_ordered_embeddings"`
+		NumCentroids             int32 `json:"num_centroids"`
+		CentroidIntermediateTopK int32 `json:"centroid_intermediate_top_k"`
+	}
+	if err := json.Unmarshal(configData, &raw); err != nil {
+		return AssistantConfig{}, fmt.Errorf("parse assistant config: %w", err)
+	}
+	if len(raw.TextConfig) == 0 {
+		return AssistantConfig{}, fmt.Errorf("assistant config missing text_config")
+	}
+
+	text, err := parseTextConfig(raw.TextConfig)
+	if err != nil {
+		return AssistantConfig{}, err
+	}
+	if raw.NumCentroids == 0 {
+		raw.NumCentroids = 2048
+	}
+	if raw.CentroidIntermediateTopK == 0 {
+		raw.CentroidIntermediateTopK = 32
+	}
+
+	return AssistantConfig{
+		TextConfig:               text,
+		BackboneHiddenSize:       raw.BackboneHiddenSize,
+		UseOrderedEmbeddings:     raw.UseOrderedEmbeddings,
+		NumCentroids:             raw.NumCentroids,
+		CentroidIntermediateTopK: raw.CentroidIntermediateTopK,
+	}, nil
+}
+
+func newAssistantModel(root *model.Root, target base.Model) (base.DraftModel, error) {
+	if root == nil || root.Draft == nil {
+		return nil, fmt.Errorf("draft metadata missing")
+	}
+
+	configPath := root.Draft.Config
+	if configPath == "" {
+		configPath = "draft/config.json"
+	}
+	configData, err := root.Manifest.ReadConfig(configPath)
+	if err != nil {
+		return nil, fmt.Errorf("load draft config: %w", err)
+	}
+
+	cfg, err := parseAssistantConfig(configData)
+	if err != nil {
+		return nil, err
+	}
+
+	targetGemma, ok := target.(*Model)
+	if !ok {
+		return nil, fmt.Errorf("gemma4 assistant requires gemma4 target, got %T", target)
+	}
+	if cfg.BackboneHiddenSize != 0 && cfg.BackboneHiddenSize != targetGemma.HiddenSize {
+		return nil, fmt.Errorf("assistant backbone hidden size %d does not match target hidden size %d", cfg.BackboneHiddenSize, targetGemma.HiddenSize)
+	}
+	if cfg.TextConfig.VocabSize != targetGemma.VocabSize {
+		return nil, fmt.Errorf("assistant vocab size %d does not match target vocab size %d", cfg.TextConfig.VocabSize, targetGemma.VocabSize)
+	}
+
+	tensorPrefix := root.Draft.TensorPrefix
+	if tensorPrefix == "" {
+		tensorPrefix = "draft."
+	}
+
+	m := &AssistantModel{
+		AssistantConfig: &cfg,
+		tensorPrefix:    tensorPrefix,
+		Layers:          make([]*AssistantLayer, cfg.TextConfig.NumHiddenLayers),
+		TensorQuant:     root.AllTensorQuant(),
+	}
+	if qt := root.QuantType(); qt != "" {
+		m.QuantGroupSize, m.QuantBits, m.QuantMode = model.QuantizationParams(qt)
+		if gs := root.GroupSize(); gs > 0 {
+			m.QuantGroupSize = gs
+		}
+	}
+	for i := range m.Layers {
+		m.Layers[i] = &AssistantLayer{
+			IsSliding: isLayerSliding(int32(i), &m.TextConfig),
+			Attention: &AssistantAttention{},
+			MLP:       &MLP{},
+		}
+	}
+	return m, nil
+}
+
+func (m *AssistantModel) LoadWeights(tensors map[string]*mlx.Array) error {
+	prefix := m.tensorPrefix
+	linears := model.NewLinearFactory(tensors, m.QuantGroupSize, m.QuantBits, m.QuantMode, m.TensorQuant)
+
+	m.PreProjection = linears.Make(prefix + "pre_projection")
+	m.PostProjection = linears.Make(prefix + "post_projection")
+	if m.PreProjection == nil || m.PostProjection == nil {
+		return fmt.Errorf("missing assistant projection weights")
+	}
+
+	m.EmbedTokens = model.MakeEmbeddingLayer(tensors, prefix+"model.embed_tokens", m.QuantGroupSize, m.QuantBits, m.QuantMode, m.TensorQuant)
+	if m.EmbedTokens == nil {
+		return fmt.Errorf("missing assistant embedding weight")
+	}
+	m.LMHead = m.EmbedTokens.AsLinear()
+
+	if m.UseOrderedEmbeddings {
+		m.Centroids = linears.Make(prefix + "masked_embedding.centroids")
+		m.TokenOrdering = tensors[prefix+"masked_embedding.token_ordering"]
+		if m.Centroids == nil || m.TokenOrdering == nil {
+			return fmt.Errorf("missing ordered embedding tensors: %smasked_embedding.centroids.weight and %smasked_embedding.token_ordering", prefix, prefix)
+		}
+		m.TokenOrdering = m.TokenOrdering.AsType(mlx.DTypeInt32)
+	}
+
+	normWeight := tensors[prefix+"model.norm.weight"]
+	if normWeight == nil {
+		return fmt.Errorf("missing assistant final norm")
+	}
+	m.Norm = nn.NewRMSNorm(normWeight, m.TextConfig.RMSNormEps)
+
+	for i := range m.TextConfig.NumHiddenLayers {
+		layerPrefix := fmt.Sprintf("%smodel.layers.%d", prefix, i)
+		layer := &AssistantLayer{
+			IsSliding: isLayerSliding(i, &m.TextConfig),
+			Attention: &AssistantAttention{
+				QProj: linears.Make(layerPrefix + ".self_attn.q_proj"),
+				OProj: linears.Make(layerPrefix + ".self_attn.o_proj"),
+			},
+			MLP: &MLP{
+				GateProj: linears.Make(layerPrefix + ".mlp.gate_proj"),
+				UpProj:   linears.Make(layerPrefix + ".mlp.up_proj"),
+				DownProj: linears.Make(layerPrefix + ".mlp.down_proj"),
+			},
+			LayerScalar: tensors[layerPrefix+".layer_scalar"],
+		}
+
+		if w := tensors[layerPrefix+".input_layernorm.weight"]; w != nil {
+			layer.InputNorm = nn.NewRMSNorm(w, m.TextConfig.RMSNormEps)
+		}
+		if w := tensors[layerPrefix+".post_attention_layernorm.weight"]; w != nil {
+			layer.PostAttnNorm = nn.NewRMSNorm(w, m.TextConfig.RMSNormEps)
+		}
+		if w := tensors[layerPrefix+".pre_feedforward_layernorm.weight"]; w != nil {
+			layer.PreFFNorm = nn.NewRMSNorm(w, m.TextConfig.RMSNormEps)
+		}
+		if w := tensors[layerPrefix+".post_feedforward_layernorm.weight"]; w != nil {
+			layer.PostFFNorm = nn.NewRMSNorm(w, m.TextConfig.RMSNormEps)
+		}
+		if w := tensors[layerPrefix+".self_attn.q_norm.weight"]; w != nil {
+			layer.Attention.QNorm = nn.NewRMSNorm(w, m.TextConfig.RMSNormEps)
+		}
+
+		if layer.InputNorm == nil || layer.PostAttnNorm == nil || layer.PreFFNorm == nil || layer.PostFFNorm == nil {
+			return fmt.Errorf("assistant layer %d: missing norm weights", i)
+		}
+		if layer.Attention.QProj == nil || layer.Attention.OProj == nil || layer.Attention.QNorm == nil {
+			return fmt.Errorf("assistant layer %d: missing attention weights", i)
+		}
+		if layer.MLP.GateProj == nil || layer.MLP.UpProj == nil || layer.MLP.DownProj == nil {
+			return fmt.Errorf("assistant layer %d: missing mlp weights", i)
+		}
+
+		m.Layers[i] = layer
+	}
+
+	m.precomputeScaledWeights()
+	return nil
+}
+
+func (m *AssistantModel) precomputeScaledWeights() {
+	if m.Norm != nil {
+		m.NormScaled = m.Norm.Weight
+	}
+	for _, layer := range m.Layers {
+		if layer.InputNorm != nil {
+			layer.InputNormScaled = layer.InputNorm.Weight
+		}
+		if layer.PostAttnNorm != nil {
+			layer.PostAttnNormScaled = layer.PostAttnNorm.Weight
+		}
+		if layer.PreFFNorm != nil {
+			layer.PreFFNormScaled = layer.PreFFNorm.Weight
+		}
+		if layer.PostFFNorm != nil {
+			layer.PostFFNormScaled = layer.PostFFNorm.Weight
+		}
+		if layer.Attention != nil && layer.Attention.QNorm != nil {
+			layer.Attention.QNormScaled = layer.Attention.QNorm.Weight
+		}
+	}
+}
+
+func (m *AssistantModel) Draft(inputsEmbeds *mlx.Array, position int32, caches []cache.Cache) (logits, hidden *mlx.Array) {
+	dims := inputsEmbeds.Dims()
+	B, L := int32(dims[0]), int32(dims[1])
+	b := &batch.Batch{
+		InputIDs:     mlx.Zeros(mlx.DTypeInt32, int(B), int(L)),
+		SeqOffsets:   []int32{position},
+		SeqQueryLens: []int32{L},
+	}
+
+	sliding, full := m.sharedHistories(b, caches)
+	h := m.PreProjection.Forward(inputsEmbeds)
+
+	positions := mlx.FromValues([]int32{position}, 1)
+	for _, layer := range m.Layers {
+		h = layer.Forward(h, b, positions, B, L, &m.TextConfig, sliding, full)
+	}
+
+	hidden = mlx.RMSNormFn(h, m.NormScaled, m.TextConfig.RMSNormEps)
+	projected := m.PostProjection.Forward(hidden)
+	return m.unembed(hidden), projected
+}
+
+func (m *AssistantModel) sharedHistories(b *batch.Batch, caches []cache.Cache) (sliding, full *nn.KVHistory) {
+	if len(caches) < 2 {
+		return nil, nil
+	}
+	if v, ok := caches[len(caches)-2].(cache.Viewer); ok {
+		sliding = v.View(b)
+	}
+	if v, ok := caches[len(caches)-1].(cache.Viewer); ok {
+		full = v.View(b)
+	}
+	return sliding, full
+}
+
+func (m *AssistantModel) unembed(hidden *mlx.Array) *mlx.Array {
+	if m.UseOrderedEmbeddings {
+		return m.applyCentroidMasking(hidden)
+	}
+	return m.LMHead.Forward(hidden)
+}
+
+func (m *AssistantModel) applyCentroidMasking(hidden *mlx.Array) *mlx.Array {
+	B, L := hidden.Dim(0), hidden.Dim(1)
+	vocab := int(m.TextConfig.VocabSize)
+	numCentroids := int(m.NumCentroids)
+	vocabPerCentroid := vocab / numCentroids
+	topK := int(m.CentroidIntermediateTopK)
+
+	centroidLogits := m.Centroids.Forward(hidden)
+	topKIndices := centroidLogits.Negative().ArgpartitionAxis(topK-1, -1).Slice(mlx.Slice(), mlx.Slice(), mlx.Slice(0, topK))
+	ordering := m.TokenOrdering.Reshape(numCentroids, vocabPerCentroid)
+	selectedCanonical := ordering.TakeAxis(topKIndices, 0)
+	selectedFlat := selectedCanonical.Reshape(B * L * topK * vocabPerCentroid)
+
+	embeddings := m.EmbedTokens.Forward(selectedFlat)
+	embeddings = embeddings.Reshape(B, L, topK*vocabPerCentroid, int(m.TextConfig.HiddenSize))
+	selectedLogits := hidden.ExpandDims(2).Matmul(embeddings.Transpose(0, 1, 3, 2)).Squeeze(2)
+
+	out := mlx.Zeros(selectedLogits.DType(), B, L, vocab)
+	out = mlx.AddScalar(out, -1.0e30)
+	return out.PutAlongAxis(selectedCanonical.Reshape(B, L, topK*vocabPerCentroid), selectedLogits, -1)
+}
+
+func (l *AssistantLayer) Forward(x *mlx.Array, b *batch.Batch, positions *mlx.Array, B, L int32, cfg *TextConfig, sliding, full *nn.KVHistory) *mlx.Array {
+	normed := mlx.RMSNormFn(x, l.InputNormScaled, cfg.RMSNormEps)
+	attnOut := l.Attention.Forward(normed, b, positions, B, L, l.IsSliding, cfg, sliding, full)
+	attnOut = mlx.RMSNormFn(attnOut, l.PostAttnNormScaled, cfg.RMSNormEps)
+	h := mlx.Add(x, attnOut)
+
+	normed = mlx.RMSNormFn(h, l.PreFFNormScaled, cfg.RMSNormEps)
+	mlpOut := l.MLP.Forward(normed)
+	mlpOut = mlx.RMSNormFn(mlpOut, l.PostFFNormScaled, cfg.RMSNormEps)
+	h = mlx.Add(h, mlpOut)
+
+	if l.LayerScalar != nil {
+		h = mlx.Mul(h, l.LayerScalar)
+	}
+	return h
+}
+
+func (a *AssistantAttention) Forward(x *mlx.Array, b *batch.Batch, positions *mlx.Array, B, L int32, isSliding bool, cfg *TextConfig, sliding, full *nn.KVHistory) *mlx.Array {
+	headDim := cfg.HeadDim
+	scale := cfg.SlidingScale
+	ropeDims := cfg.SlidingRopeDims
+	ropeBase := cfg.SlidingRopeBase
+	history := sliding
+	if !isSliding {
+		headDim = cfg.GlobalHeadDim
+		scale = cfg.FullScale
+		ropeDims = cfg.FullRopeDims
+		ropeBase = cfg.FullRopeBase
+		history = full
+	}
+	if history == nil {
+		panic("gemma4 assistant missing shared target KV history")
+	}
+
+	q := a.QProj.Forward(x)
+	q = mlx.Reshape(q, B, L, cfg.NumAttentionHeads, headDim)
+	q = mlx.Transpose(q, 0, 2, 1, 3)
+	q = mlx.RMSNormFn(q, a.QNormScaled, cfg.RMSNormEps)
+
+	var ropeFreqs *mlx.Array
+	if !isSliding {
+		ropeFreqs = cfg.FullRopeFreqs
+	}
+	q = mlx.RoPEWithFreqs(q, ropeDims, false, ropeBase, 1.0, positions, ropeFreqs)
+
+	mask := nn.CausalMask()
+	if isSliding && cfg.SlidingWindow > 0 {
+		mask = mask.Intersect(nn.SlidingWindowMask(b, history.K().Dim(2), int(cfg.SlidingWindow), q.DType()))
+	}
+
+	out := nn.ScaledDotProductAttention(b, q, scale, nn.WithKVHistory(history), nn.WithMask(mask))
+	out = mlx.Reshape(mlx.Transpose(out, 0, 2, 1, 3), B, L, cfg.NumAttentionHeads*headDim)
+	if !mlx.MetalIsAvailable() {
+		out = mlx.Contiguous(out, false)
+	}
+	return a.OProj.Forward(out)
+}

x/models/gemma4/gemma4.go

@@ -18,10 +18,15 @@ import (
 func init() {
 	base.Register("Gemma4ForCausalLM", newModel)
 	base.Register("Gemma4ForConditionalGeneration", newModel)
+	base.RegisterDraft("Gemma4AssistantForCausalLM", newAssistantModel)
+	base.RegisterDraft("gemma4_assistant", newAssistantModel)
 }
 
 // Compile-time interface checks.
-var _ base.Model = (*Model)(nil)
+var (
+	_ base.Model               = (*Model)(nil)
+	_ base.MTPDefaultsProvider = (*Model)(nil)
+)
 
 // RopeParams holds per-layer-type RoPE settings.
 type RopeParams struct {
@@ -466,6 +471,24 @@ func (m *Model) EnableCompile() bool {
 	return true
 }
 
+func (m *Model) MTPDraftDefaults(_ bool) base.MTPDefaults {
+	defaults := base.MTPDefaults{
+		InitialDraftTokens: 4,
+		MaxDraftTokens:     16,
+		Enabled:            true,
+	}
+	if m == nil || m.TextConfig == nil {
+		return defaults
+	}
+	switch {
+	case !m.EnableMoeBlock && m.HiddenSize == 5376 && m.NumHiddenLayers == 60:
+		defaults.InitialDraftTokens = 14
+	case m.EnableMoeBlock && m.HiddenSize == 2816 && m.NumHiddenLayers == 30:
+		defaults.InitialDraftTokens = 8
+	}
+	return defaults
+}
+
 func resolveWeightPrefix(tensors map[string]*mlx.Array) string {
 	for _, prefix := range []string{"", "language_model.", "model.language_model."} {
 		if tensors[prefix+"embed_tokens.weight"] != nil {
@@ -1068,6 +1091,11 @@ func (m *Model) Tokenizer() *tokenizer.Tokenizer {
 	return m.tok
 }
 
+// TokenEmbeddings returns the target model's scaled token embeddings for MTP.
+func (m *Model) TokenEmbeddings(inputIDs *mlx.Array) *mlx.Array {
+	return mlx.MulScalar(m.EmbedTokens.Forward(inputIDs), m.EmbedScale)
+}
+
 // NewCaches creates cache objects for layers that own KV state.
 func (m *Model) NewCaches() []cache.Cache {
 	cacheLayers := len(m.Layers)

x/models/gemma4/gemma4_test.go

@@ -434,6 +434,54 @@ func TestLayerTypeDetection(t *testing.T) {
 	}
 }
 
+func TestMTPDraftDefaults(t *testing.T) {
+	tests := []struct {
+		name        string
+		cfg         *TextConfig
+		wantInitial int
+		wantMax     int
+	}{
+		{
+			name:        "nil config",
+			wantInitial: 4,
+			wantMax:     16,
+		},
+		{
+			name:        "31b bf16",
+			cfg:         &TextConfig{HiddenSize: 5376, NumHiddenLayers: 60},
+			wantInitial: 14,
+			wantMax:     16,
+		},
+		{
+			name:        "31b quantized",
+			cfg:         &TextConfig{HiddenSize: 5376, NumHiddenLayers: 60, QuantBits: 4},
+			wantInitial: 14,
+			wantMax:     16,
+		},
+		{
+			name:        "26b-a4b moe",
+			cfg:         &TextConfig{HiddenSize: 2816, NumHiddenLayers: 30, EnableMoeBlock: true},
+			wantInitial: 8,
+			wantMax:     16,
+		},
+		{
+			name:        "generic default",
+			cfg:         &TextConfig{HiddenSize: 2560, NumHiddenLayers: 42, HiddenSizePerLayer: 256},
+			wantInitial: 4,
+			wantMax:     16,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := (&Model{TextConfig: tt.cfg}).MTPDraftDefaults(false)
+			if got.InitialDraftTokens != tt.wantInitial || got.MaxDraftTokens != tt.wantMax || !got.Enabled {
+				t.Fatalf("MTPDraftDefaults() = %+v, want initial=%d max=%d enabled=true", got, tt.wantInitial, tt.wantMax)
+			}
+		})
+	}
+}
+
 func TestNewCachesOmitsSharedKVLayers(t *testing.T) {
 	m := &Model{
 		Layers: []*DecoderLayer{
@@ -467,6 +515,55 @@ func TestNewCachesIncludesAllNonSharedLayers(t *testing.T) {
 	}
 }
 
+func TestNewCachesAssistantSharedHistoryOrdering(t *testing.T) {
+	cases := []struct {
+		name              string
+		totalLayers       int
+		slidingBeforeFull int
+		cacheLayers       int
+	}{
+		{name: "31B", totalLayers: 60, slidingBeforeFull: 5, cacheLayers: 60},
+		{name: "26B-A4B", totalLayers: 30, slidingBeforeFull: 5, cacheLayers: 30},
+		{name: "E4B", totalLayers: 42, slidingBeforeFull: 5, cacheLayers: 24},
+		{name: "E2B", totalLayers: 35, slidingBeforeFull: 4, cacheLayers: 15},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			groupSize := tc.slidingBeforeFull + 1
+			layers := make([]*DecoderLayer, tc.totalLayers)
+			for i := range layers {
+				donor := int32(-1)
+				if i >= tc.cacheLayers {
+					donor = 0
+				}
+				layers[i] = &DecoderLayer{
+					IsSliding:    i%groupSize < tc.slidingBeforeFull,
+					KVShareDonor: donor,
+				}
+			}
+
+			m := &Model{
+				Layers:     layers,
+				TextConfig: &TextConfig{SlidingWindow: 512},
+			}
+			caches := m.NewCaches()
+			if got := len(caches); got != tc.cacheLayers {
+				t.Fatalf("len(NewCaches()) = %d, want %d", got, tc.cacheLayers)
+			}
+
+			gotSliding := len(caches) - 2
+			gotFull := len(caches) - 1
+			if !m.Layers[gotSliding].IsSliding {
+				t.Fatalf("cache %d should be sliding attention", gotSliding)
+			}
+			if m.Layers[gotFull].IsSliding {
+				t.Fatalf("cache %d should be full attention", gotFull)
+			}
+		})
+	}
+}
+
 func TestResolveWeightPrefix(t *testing.T) {
 	if err := mlx.CheckInit(); err != nil {
 		t.Skipf("MLX not available: %v", err)