diff --git a/middleware/openai.go b/middleware/openai.go
new file mode 100644
index 000000000..826a2111b
--- /dev/null
+++ b/middleware/openai.go
@@ -0,0 +1,424 @@
+package middleware
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"math/rand"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/ollama/ollama/api"
+	"github.com/ollama/ollama/openai"
+)
+
+type BaseWriter struct {
+	gin.ResponseWriter
+}
+
+type ChatWriter struct {
+	stream        bool
+	streamOptions *openai.StreamOptions
+	id            string
+	toolCallSent  bool
+	BaseWriter
+}
+
+type CompleteWriter struct {
+	stream        bool
+	streamOptions *openai.StreamOptions
+	id            string
+	BaseWriter
+}
+
+type ListWriter struct {
+	BaseWriter
+}
+
+type RetrieveWriter struct {
+	BaseWriter
+	model string
+}
+
+type EmbedWriter struct {
+	BaseWriter
+	model string
+}
+
+func (w *BaseWriter) writeError(data []byte) (int, error) {
+	var serr api.StatusError
+	err := json.Unmarshal(data, &serr)
+	if err != nil {
+		return 0, err
+	}
+
+	w.ResponseWriter.Header().Set("Content-Type", "application/json")
+	err = json.NewEncoder(w.ResponseWriter).Encode(openai.NewError(http.StatusInternalServerError, serr.Error()))
+	if err != nil {
+		return 0, err
+	}
+
+	return len(data), nil
+}
+
+func (w *ChatWriter) writeResponse(data []byte) (int, error) {
+	var chatResponse api.ChatResponse
+	err := json.Unmarshal(data, &chatResponse)
+	if err != nil {
+		return 0, err
+	}
+
+	// chat chunk
+	if w.stream {
+		c := openai.ToChunk(w.id, chatResponse, w.toolCallSent)
+		d, err := json.Marshal(c)
+		if err != nil {
+			return 0, err
+		}
+		if !w.toolCallSent && len(c.Choices) > 0 && len(c.Choices[0].Delta.ToolCalls) > 0 {
+			w.toolCallSent = true
+		}
+
+		w.ResponseWriter.Header().Set("Content-Type", "text/event-stream")
+		_, err = w.ResponseWriter.Write([]byte(fmt.Sprintf("data: %s\n\n", d)))
+		if err != nil {
+			return 0, err
+		}
+
+		if chatResponse.Done {
+			if w.streamOptions != nil && w.streamOptions.IncludeUsage {
+				u := openai.ToUsage(chatResponse)
+				c.Usage = &u
+				c.Choices = []openai.ChunkChoice{}
+				d, err := json.Marshal(c)
+				if err != nil {
+					return 0, err
+				}
+				_, err = w.ResponseWriter.Write([]byte(fmt.Sprintf("data: %s\n\n", d)))
+				if err != nil {
+					return 0, err
+				}
+			}
+			_, err = w.ResponseWriter.Write([]byte("data: [DONE]\n\n"))
+			if err != nil {
+				return 0, err
+			}
+		}
+
+		return len(data), nil
+	}
+
+	// chat completion
+	w.ResponseWriter.Header().Set("Content-Type", "application/json")
+	err = json.NewEncoder(w.ResponseWriter).Encode(openai.ToChatCompletion(w.id, chatResponse))
+	if err != nil {
+		return 0, err
+	}
+
+	return len(data), nil
+}
+
+func (w *ChatWriter) Write(data []byte) (int, error) {
+	code := w.ResponseWriter.Status()
+	if code != http.StatusOK {
+		return w.writeError(data)
+	}
+
+	return w.writeResponse(data)
+}
+
+func (w *CompleteWriter) writeResponse(data []byte) (int, error) {
+	var generateResponse api.GenerateResponse
+	err := json.Unmarshal(data, &generateResponse)
+	if err != nil {
+		return 0, err
+	}
+
+	// completion chunk
+	if w.stream {
+		c := openai.ToCompleteChunk(w.id, generateResponse)
+		if w.streamOptions != nil && w.streamOptions.IncludeUsage {
+			c.Usage = &openai.Usage{}
+		}
+		d, err := json.Marshal(c)
+		if err != nil {
+			return 0, err
+		}
+
+		w.ResponseWriter.Header().Set("Content-Type", "text/event-stream")
+		_, err = w.ResponseWriter.Write([]byte(fmt.Sprintf("data: %s\n\n", d)))
+		if err != nil {
+			return 0, err
+		}
+
+		if generateResponse.Done {
+			if w.streamOptions != nil && w.streamOptions.IncludeUsage {
+				u := openai.ToUsageGenerate(generateResponse)
+				c.Usage = &u
+				c.Choices = []openai.CompleteChunkChoice{}
+				d, err := json.Marshal(c)
+				if err != nil {
+					return 0, err
+				}
+				_, err = w.ResponseWriter.Write([]byte(fmt.Sprintf("data: %s\n\n", d)))
+				if err != nil {
+					return 0, err
+				}
+			}
+			_, err = w.ResponseWriter.Write([]byte("data: [DONE]\n\n"))
+			if err != nil {
+				return 0, err
+			}
+		}
+
+		return len(data), nil
+	}
+
+	// completion
+	w.ResponseWriter.Header().Set("Content-Type", "application/json")
+	err = json.NewEncoder(w.ResponseWriter).Encode(openai.ToCompletion(w.id, generateResponse))
+	if err != nil {
+		return 0, err
+	}
+
+	return len(data), nil
+}
+
+func (w *CompleteWriter) Write(data []byte) (int, error) {
+	code := w.ResponseWriter.Status()
+	if code != http.StatusOK {
+		return w.writeError(data)
+	}
+
+	return w.writeResponse(data)
+}
+
+func (w *ListWriter) writeResponse(data []byte) (int, error) {
+	var listResponse api.ListResponse
+	err := json.Unmarshal(data, &listResponse)
+	if err != nil {
+		return 0, err
+	}
+
+	w.ResponseWriter.Header().Set("Content-Type", "application/json")
+	err = json.NewEncoder(w.ResponseWriter).Encode(openai.ToListCompletion(listResponse))
+	if err != nil {
+		return 0, err
+	}
+
+	return len(data), nil
+}
+
+func (w *ListWriter) Write(data []byte) (int, error) {
+	code := w.ResponseWriter.Status()
+	if code != http.StatusOK {
+		return w.writeError(data)
+	}
+
+	return w.writeResponse(data)
+}
+
+func (w *RetrieveWriter) writeResponse(data []byte) (int, error) {
+	var showResponse api.ShowResponse
+	err := json.Unmarshal(data, &showResponse)
+	if err != nil {
+		return 0, err
+	}
+
+	// retrieve completion
+	w.ResponseWriter.Header().Set("Content-Type", "application/json")
+	err = json.NewEncoder(w.ResponseWriter).Encode(openai.ToModel(showResponse, w.model))
+	if err != nil {
+		return 0, err
+	}
+
+	return len(data), nil
+}
+
+func (w *RetrieveWriter) Write(data []byte) (int, error) {
+	code := w.ResponseWriter.Status()
+	if code != http.StatusOK {
+		return w.writeError(data)
+	}
+
+	return w.writeResponse(data)
+}
+
+func (w *EmbedWriter) writeResponse(data []byte) (int, error) {
+	var embedResponse api.EmbedResponse
+	err := json.Unmarshal(data, &embedResponse)
+	if err != nil {
+		return 0, err
+	}
+
+	w.ResponseWriter.Header().Set("Content-Type", "application/json")
+	err = json.NewEncoder(w.ResponseWriter).Encode(openai.ToEmbeddingList(w.model, embedResponse))
+	if err != nil {
+		return 0, err
+	}
+
+	return len(data), nil
+}
+
+func (w *EmbedWriter) Write(data []byte) (int, error) {
+	code := w.ResponseWriter.Status()
+	if code != http.StatusOK {
+		return w.writeError(data)
+	}
+
+	return w.writeResponse(data)
+}
+
+func ListMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		w := &ListWriter{
+			BaseWriter: BaseWriter{ResponseWriter: c.Writer},
+		}
+
+		c.Writer = w
+
+		c.Next()
+	}
+}
+
+func RetrieveMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		var b bytes.Buffer
+		if err := json.NewEncoder(&b).Encode(api.ShowRequest{Name: c.Param("model")}); err != nil {
+			c.AbortWithStatusJSON(http.StatusInternalServerError, openai.NewError(http.StatusInternalServerError, err.Error()))
+			return
+		}
+
+		c.Request.Body = io.NopCloser(&b)
+
+		w := &RetrieveWriter{
+			BaseWriter: BaseWriter{ResponseWriter: c.Writer},
+			model:      c.Param("model"),
+		}
+
+		c.Writer = w
+
+		c.Next()
+	}
+}
+
+func CompletionsMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		var req openai.CompletionRequest
+		err := c.ShouldBindJSON(&req)
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusBadRequest, openai.NewError(http.StatusBadRequest, err.Error()))
+			return
+		}
+
+		var b bytes.Buffer
+		genReq, err := openai.FromCompleteRequest(req)
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusBadRequest, openai.NewError(http.StatusBadRequest, err.Error()))
+			return
+		}
+
+		if err := json.NewEncoder(&b).Encode(genReq); err != nil {
+			c.AbortWithStatusJSON(http.StatusInternalServerError, openai.NewError(http.StatusInternalServerError, err.Error()))
+			return
+		}
+
+		c.Request.Body = io.NopCloser(&b)
+
+		w := &CompleteWriter{
+			BaseWriter:    BaseWriter{ResponseWriter: c.Writer},
+			stream:        req.Stream,
+			id:            fmt.Sprintf("cmpl-%d", rand.Intn(999)),
+			streamOptions: req.StreamOptions,
+		}
+
+		c.Writer = w
+		c.Next()
+	}
+}
+
+func EmbeddingsMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		var req openai.EmbedRequest
+		err := c.ShouldBindJSON(&req)
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusBadRequest, openai.NewError(http.StatusBadRequest, err.Error()))
+			return
+		}
+
+		if req.Input == "" {
+			req.Input = []string{""}
+		}
+
+		if req.Input == nil {
+			c.AbortWithStatusJSON(http.StatusBadRequest, openai.NewError(http.StatusBadRequest, "invalid input"))
+			return
+		}
+
+		if v, ok := req.Input.([]any); ok && len(v) == 0 {
+			c.AbortWithStatusJSON(http.StatusBadRequest, openai.NewError(http.StatusBadRequest, "invalid input"))
+			return
+		}
+
+		var b bytes.Buffer
+		if err := json.NewEncoder(&b).Encode(api.EmbedRequest{Model: req.Model, Input: req.Input, Dimensions: req.Dimensions}); err != nil {
+			c.AbortWithStatusJSON(http.StatusInternalServerError, openai.NewError(http.StatusInternalServerError, err.Error()))
+			return
+		}
+
+		c.Request.Body = io.NopCloser(&b)
+
+		w := &EmbedWriter{
+			BaseWriter: BaseWriter{ResponseWriter: c.Writer},
+			model:      req.Model,
+		}
+
+		c.Writer = w
+
+		c.Next()
+	}
+}
+
+func ChatMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		var req openai.ChatCompletionRequest
+		err := c.ShouldBindJSON(&req)
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusBadRequest, openai.NewError(http.StatusBadRequest, err.Error()))
+			return
+		}
+
+		if len(req.Messages) == 0 {
+			c.AbortWithStatusJSON(http.StatusBadRequest, openai.NewError(http.StatusBadRequest, "[] is too short - 'messages'"))
+			return
+		}
+
+		var b bytes.Buffer
+
+		chatReq, err := openai.FromChatRequest(req)
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusBadRequest, openai.NewError(http.StatusBadRequest, err.Error()))
+			return
+		}
+
+		if err := json.NewEncoder(&b).Encode(chatReq); err != nil {
+			c.AbortWithStatusJSON(http.StatusInternalServerError, openai.NewError(http.StatusInternalServerError, err.Error()))
+			return
+		}
+
+		c.Request.Body = io.NopCloser(&b)
+
+		w := &ChatWriter{
+			BaseWriter:    BaseWriter{ResponseWriter: c.Writer},
+			stream:        req.Stream,
+			id:            fmt.Sprintf("chatcmpl-%d", rand.Intn(999)),
+			streamOptions: req.StreamOptions,
+		}
+
+		c.Writer = w
+
+		c.Next()
+	}
+}
diff --git a/middleware/openai_test.go b/middleware/openai_test.go
new file mode 100644
index 000000000..a78ee8b91
--- /dev/null
+++ b/middleware/openai_test.go
@@ -0,0 +1,928 @@
+package middleware
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/go-cmp/cmp"
+
+	"github.com/ollama/ollama/api"
+	"github.com/ollama/ollama/openai"
+)
+
+const (
+	prefix = `data:image/jpeg;base64,`
+	image  = `iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+A8AAQUBAScY42YAAAAASUVORK5CYII=`
+)
+
+var (
+	False = false
+	True  = true
+)
+
+func captureRequestMiddleware(capturedRequest any) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		bodyBytes, _ := io.ReadAll(c.Request.Body)
+		c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes))
+		err := json.Unmarshal(bodyBytes, capturedRequest)
+		if err != nil {
+			c.AbortWithStatusJSON(http.StatusInternalServerError, "failed to unmarshal request")
+		}
+		c.Next()
+	}
+}
+
+func TestChatMiddleware(t *testing.T) {
+	type testCase struct {
+		name string
+		body string
+		req  api.ChatRequest
+		err  openai.ErrorResponse
+	}
+
+	var capturedRequest *api.ChatRequest
+
+	testCases := []testCase{
+		{
+			name: "chat handler",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "Hello"}
+				]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "Hello",
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &False,
+			},
+		},
+		{
+			name: "chat handler with options",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "Hello"}
+				],
+				"stream":            true,
+				"max_tokens":        999,
+				"seed":              123,
+				"stop":              ["\n", "stop"],
+				"temperature":       3.0,
+				"frequency_penalty": 4.0,
+				"presence_penalty":  5.0,
+				"top_p":             6.0,
+				"response_format":   {"type": "json_object"}
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "Hello",
+					},
+				},
+				Options: map[string]any{
+					"num_predict":       999.0, // float because JSON doesn't distinguish between float and int
+					"seed":              123.0,
+					"stop":              []any{"\n", "stop"},
+					"temperature":       3.0,
+					"frequency_penalty": 4.0,
+					"presence_penalty":  5.0,
+					"top_p":             6.0,
+				},
+				Format: json.RawMessage(`"json"`),
+				Stream: &True,
+			},
+		},
+		{
+			name: "chat handler with streaming usage",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "Hello"}
+				],
+				"stream":            true,
+				"stream_options":    {"include_usage": true},
+				"max_tokens":        999,
+				"seed":              123,
+				"stop":              ["\n", "stop"],
+				"temperature":       3.0,
+				"frequency_penalty": 4.0,
+				"presence_penalty":  5.0,
+				"top_p":             6.0,
+				"response_format":   {"type": "json_object"}
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "Hello",
+					},
+				},
+				Options: map[string]any{
+					"num_predict":       999.0, // float because JSON doesn't distinguish between float and int
+					"seed":              123.0,
+					"stop":              []any{"\n", "stop"},
+					"temperature":       3.0,
+					"frequency_penalty": 4.0,
+					"presence_penalty":  5.0,
+					"top_p":             6.0,
+				},
+				Format: json.RawMessage(`"json"`),
+				Stream: &True,
+			},
+		},
+		{
+			name: "chat handler with image content",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{
+						"role": "user",
+						"content": [
+							{
+								"type": "text",
+								"text": "Hello"
+							},
+							{
+								"type": "image_url",
+								"image_url": {
+									"url": "` + prefix + image + `"
+								}
+							}
+						]
+					}
+				]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "Hello",
+					},
+					{
+						Role: "user",
+						Images: []api.ImageData{
+							func() []byte {
+								img, _ := base64.StdEncoding.DecodeString(image)
+								return img
+							}(),
+						},
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &False,
+			},
+		},
+		{
+			name: "chat handler with tools",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "What's the weather like in Paris Today?"},
+					{"role": "assistant", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]}
+				]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "What's the weather like in Paris Today?",
+					},
+					{
+						Role: "assistant",
+						ToolCalls: []api.ToolCall{
+							{
+								Function: api.ToolCallFunction{
+									Name: "get_current_weather",
+									Arguments: map[string]any{
+										"location": "Paris, France",
+										"format":   "celsius",
+									},
+								},
+							},
+						},
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &False,
+			},
+		},
+		{
+			name: "chat handler with tools and content",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "What's the weather like in Paris Today?"},
+					{"role": "assistant", "content": "Let's see what the weather is like in Paris", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]}
+				]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "What's the weather like in Paris Today?",
+					},
+					{
+						Role:    "assistant",
+						Content: "Let's see what the weather is like in Paris",
+						ToolCalls: []api.ToolCall{
+							{
+								Function: api.ToolCallFunction{
+									Name: "get_current_weather",
+									Arguments: map[string]any{
+										"location": "Paris, France",
+										"format":   "celsius",
+									},
+								},
+							},
+						},
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &False,
+			},
+		},
+		{
+			name: "chat handler with tools and empty content",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "What's the weather like in Paris Today?"},
+					{"role": "assistant", "content": "", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]}
+				]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "What's the weather like in Paris Today?",
+					},
+					{
+						Role: "assistant",
+						ToolCalls: []api.ToolCall{
+							{
+								Function: api.ToolCallFunction{
+									Name: "get_current_weather",
+									Arguments: map[string]any{
+										"location": "Paris, France",
+										"format":   "celsius",
+									},
+								},
+							},
+						},
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &False,
+			},
+		},
+		{
+			name: "chat handler with tools and thinking content",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "What's the weather like in Paris Today?"},
+					{"role": "assistant", "reasoning": "Let's see what the weather is like in Paris", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]}
+				]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "What's the weather like in Paris Today?",
+					},
+					{
+						Role:     "assistant",
+						Thinking: "Let's see what the weather is like in Paris",
+						ToolCalls: []api.ToolCall{
+							{
+								Function: api.ToolCallFunction{
+									Name: "get_current_weather",
+									Arguments: map[string]any{
+										"location": "Paris, France",
+										"format":   "celsius",
+									},
+								},
+							},
+						},
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &False,
+			},
+		},
+		{
+			name: "tool response with call ID",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "What's the weather like in Paris Today?"},
+					{"role": "assistant", "tool_calls": [{"id": "id_abc", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]},
+					{"role": "tool", "tool_call_id": "id_abc", "content": "The weather in Paris is 20 degrees Celsius"}
+				]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "What's the weather like in Paris Today?",
+					},
+					{
+						Role: "assistant",
+						ToolCalls: []api.ToolCall{
+							{
+								Function: api.ToolCallFunction{
+									Name: "get_current_weather",
+									Arguments: map[string]any{
+										"location": "Paris, France",
+										"format":   "celsius",
+									},
+								},
+							},
+						},
+					},
+					{
+						Role:     "tool",
+						Content:  "The weather in Paris is 20 degrees Celsius",
+						ToolName: "get_current_weather",
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &False,
+			},
+		},
+		{
+			name: "tool response with name",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "What's the weather like in Paris Today?"},
+					{"role": "assistant", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]},
+					{"role": "tool", "name": "get_current_weather", "content": "The weather in Paris is 20 degrees Celsius"}
+				]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "What's the weather like in Paris Today?",
+					},
+					{
+						Role: "assistant",
+						ToolCalls: []api.ToolCall{
+							{
+								Function: api.ToolCallFunction{
+									Name: "get_current_weather",
+									Arguments: map[string]any{
+										"location": "Paris, France",
+										"format":   "celsius",
+									},
+								},
+							},
+						},
+					},
+					{
+						Role:     "tool",
+						Content:  "The weather in Paris is 20 degrees Celsius",
+						ToolName: "get_current_weather",
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &False,
+			},
+		},
+		{
+			name: "chat handler with streaming tools",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": "What's the weather like in Paris?"}
+				],
+				"stream": true,
+				"tools": [{
+					"type": "function",
+					"function": {
+						"name": "get_weather",
+						"description": "Get the current weather",
+						"parameters": {
+							"type": "object",
+							"required": ["location"],
+							"properties": {
+								"location": {
+									"type": "string",
+									"description": "The city and state"
+								},
+								"unit": {
+									"type": "string",
+									"enum": ["celsius", "fahrenheit"]
+								}
+							}
+						}
+					}
+				}]
+			}`,
+			req: api.ChatRequest{
+				Model: "test-model",
+				Messages: []api.Message{
+					{
+						Role:    "user",
+						Content: "What's the weather like in Paris?",
+					},
+				},
+				Tools: []api.Tool{
+					{
+						Type: "function",
+						Function: api.ToolFunction{
+							Name:        "get_weather",
+							Description: "Get the current weather",
+							Parameters: struct {
+								Type       string                      `json:"type"`
+								Defs       any                         `json:"$defs,omitempty"`
+								Items      any                         `json:"items,omitempty"`
+								Required   []string                    `json:"required"`
+								Properties map[string]api.ToolProperty `json:"properties"`
+							}{
+								Type:     "object",
+								Required: []string{"location"},
+								Properties: map[string]api.ToolProperty{
+									"location": {
+										Type:        api.PropertyType{"string"},
+										Description: "The city and state",
+									},
+									"unit": {
+										Type: api.PropertyType{"string"},
+										Enum: []any{"celsius", "fahrenheit"},
+									},
+								},
+							},
+						},
+					},
+				},
+				Options: map[string]any{
+					"temperature": 1.0,
+					"top_p":       1.0,
+				},
+				Stream: &True,
+			},
+		},
+		{
+			name: "chat handler error forwarding",
+			body: `{
+				"model": "test-model",
+				"messages": [
+					{"role": "user", "content": 2}
+				]
+			}`,
+			err: openai.ErrorResponse{
+				Error: openai.Error{
+					Message: "invalid message content type: float64",
+					Type:    "invalid_request_error",
+				},
+			},
+		},
+	}
+
+	endpoint := func(c *gin.Context) {
+		c.Status(http.StatusOK)
+	}
+
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	router.Use(ChatMiddleware(), captureRequestMiddleware(&capturedRequest))
+	router.Handle(http.MethodPost, "/api/chat", endpoint)
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			req, _ := http.NewRequest(http.MethodPost, "/api/chat", strings.NewReader(tc.body))
+			req.Header.Set("Content-Type", "application/json")
+
+			defer func() { capturedRequest = nil }()
+
+			resp := httptest.NewRecorder()
+			router.ServeHTTP(resp, req)
+
+			var errResp openai.ErrorResponse
+			if resp.Code != http.StatusOK {
+				if err := json.Unmarshal(resp.Body.Bytes(), &errResp); err != nil {
+					t.Fatal(err)
+				}
+				return
+			}
+			if diff := cmp.Diff(&tc.req, capturedRequest); diff != "" {
+				t.Fatalf("requests did not match: %+v", diff)
+			}
+			if diff := cmp.Diff(tc.err, errResp); diff != "" {
+				t.Fatalf("errors did not match for %s:\n%s", tc.name, diff)
+			}
+		})
+	}
+}
+
+func TestCompletionsMiddleware(t *testing.T) {
+	type testCase struct {
+		name string
+		body string
+		req  api.GenerateRequest
+		err  openai.ErrorResponse
+	}
+
+	var capturedRequest *api.GenerateRequest
+
+	testCases := []testCase{
+		{
+			name: "completions handler",
+			body: `{
+				"model": "test-model",
+				"prompt": "Hello",
+				"temperature": 0.8,
+				"stop": ["\n", "stop"],
+				"suffix": "suffix"
+			}`,
+			req: api.GenerateRequest{
+				Model:  "test-model",
+				Prompt: "Hello",
+				Options: map[string]any{
+					"frequency_penalty": 0.0,
+					"presence_penalty":  0.0,
+					"temperature":       0.8,
+					"top_p":             1.0,
+					"stop":              []any{"\n", "stop"},
+				},
+				Suffix: "suffix",
+				Stream: &False,
+			},
+		},
+		{
+			name: "completions handler stream",
+			body: `{
+				"model": "test-model",
+				"prompt": "Hello",
+				"stream": true,
+				"temperature": 0.8,
+				"stop": ["\n", "stop"],
+				"suffix": "suffix"
+			}`,
+			req: api.GenerateRequest{
+				Model:  "test-model",
+				Prompt: "Hello",
+				Options: map[string]any{
+					"frequency_penalty": 0.0,
+					"presence_penalty":  0.0,
+					"temperature":       0.8,
+					"top_p":             1.0,
+					"stop":              []any{"\n", "stop"},
+				},
+				Suffix: "suffix",
+				Stream: &True,
+			},
+		},
+		{
+			name: "completions handler stream with usage",
+			body: `{
+				"model": "test-model",
+				"prompt": "Hello",
+				"stream": true,
+				"stream_options": {"include_usage": true},
+				"temperature": 0.8,
+				"stop": ["\n", "stop"],
+				"suffix": "suffix"
+			}`,
+			req: api.GenerateRequest{
+				Model:  "test-model",
+				Prompt: "Hello",
+				Options: map[string]any{
+					"frequency_penalty": 0.0,
+					"presence_penalty":  0.0,
+					"temperature":       0.8,
+					"top_p":             1.0,
+					"stop":              []any{"\n", "stop"},
+				},
+				Suffix: "suffix",
+				Stream: &True,
+			},
+		},
+		{
+			name: "completions handler error forwarding",
+			body: `{
+				"model": "test-model",
+				"prompt": "Hello",
+				"temperature": null,
+				"stop": [1, 2],
+				"suffix": "suffix"
+			}`,
+			err: openai.ErrorResponse{
+				Error: openai.Error{
+					Message: "invalid type for 'stop' field: float64",
+					Type:    "invalid_request_error",
+				},
+			},
+		},
+	}
+
+	endpoint := func(c *gin.Context) {
+		c.Status(http.StatusOK)
+	}
+
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	router.Use(CompletionsMiddleware(), captureRequestMiddleware(&capturedRequest))
+	router.Handle(http.MethodPost, "/api/generate", endpoint)
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			req, _ := http.NewRequest(http.MethodPost, "/api/generate", strings.NewReader(tc.body))
+			req.Header.Set("Content-Type", "application/json")
+
+			resp := httptest.NewRecorder()
+			router.ServeHTTP(resp, req)
+
+			var errResp openai.ErrorResponse
+			if resp.Code != http.StatusOK {
+				if err := json.Unmarshal(resp.Body.Bytes(), &errResp); err != nil {
+					t.Fatal(err)
+				}
+			}
+
+			if capturedRequest != nil && !reflect.DeepEqual(tc.req, *capturedRequest) {
+				t.Fatal("requests did not match")
+			}
+
+			if !reflect.DeepEqual(tc.err, errResp) {
+				t.Fatal("errors did not match")
+			}
+
+			capturedRequest = nil
+		})
+	}
+}
+
+func TestEmbeddingsMiddleware(t *testing.T) {
+	type testCase struct {
+		name string
+		body string
+		req  api.EmbedRequest
+		err  openai.ErrorResponse
+	}
+
+	var capturedRequest *api.EmbedRequest
+
+	testCases := []testCase{
+		{
+			name: "embed handler single input",
+			body: `{
+				"input": "Hello",
+				"model": "test-model"
+			}`,
+			req: api.EmbedRequest{
+				Input: "Hello",
+				Model: "test-model",
+			},
+		},
+		{
+			name: "embed handler batch input",
+			body: `{
+				"input": ["Hello", "World"],
+				"model": "test-model"
+			}`,
+			req: api.EmbedRequest{
+				Input: []any{"Hello", "World"},
+				Model: "test-model",
+			},
+		},
+		{
+			name: "embed handler error forwarding",
+			body: `{
+				"model": "test-model"
+			}`,
+			err: openai.ErrorResponse{
+				Error: openai.Error{
+					Message: "invalid input",
+					Type:    "invalid_request_error",
+				},
+			},
+		},
+	}
+
+	endpoint := func(c *gin.Context) {
+		c.Status(http.StatusOK)
+	}
+
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	router.Use(EmbeddingsMiddleware(), captureRequestMiddleware(&capturedRequest))
+	router.Handle(http.MethodPost, "/api/embed", endpoint)
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			req, _ := http.NewRequest(http.MethodPost, "/api/embed", strings.NewReader(tc.body))
+			req.Header.Set("Content-Type", "application/json")
+
+			resp := httptest.NewRecorder()
+			router.ServeHTTP(resp, req)
+
+			var errResp openai.ErrorResponse
+			if resp.Code != http.StatusOK {
+				if err := json.Unmarshal(resp.Body.Bytes(), &errResp); err != nil {
+					t.Fatal(err)
+				}
+			}
+
+			if capturedRequest != nil && !reflect.DeepEqual(tc.req, *capturedRequest) {
+				t.Fatal("requests did not match")
+			}
+
+			if !reflect.DeepEqual(tc.err, errResp) {
+				t.Fatal("errors did not match")
+			}
+
+			capturedRequest = nil
+		})
+	}
+}
+
+func TestListMiddleware(t *testing.T) {
+	type testCase struct {
+		name     string
+		endpoint func(c *gin.Context)
+		resp     string
+	}
+
+	testCases := []testCase{
+		{
+			name: "list handler",
+			endpoint: func(c *gin.Context) {
+				c.JSON(http.StatusOK, api.ListResponse{
+					Models: []api.ListModelResponse{
+						{
+							Name:       "test-model",
+							ModifiedAt: time.Unix(int64(1686935002), 0).UTC(),
+						},
+					},
+				})
+			},
+			resp: `{
+				"object": "list",
+				"data": [
+					{
+						"id": "test-model",
+						"object": "model",
+						"created": 1686935002,
+						"owned_by": "library"
+					}
+				]
+			}`,
+		},
+		{
+			name: "list handler empty output",
+			endpoint: func(c *gin.Context) {
+				c.JSON(http.StatusOK, api.ListResponse{})
+			},
+			resp: `{
+				"object": "list",
+				"data": null
+			}`,
+		},
+	}
+
+	gin.SetMode(gin.TestMode)
+
+	for _, tc := range testCases {
+		router := gin.New()
+		router.Use(ListMiddleware())
+		router.Handle(http.MethodGet, "/api/tags", tc.endpoint)
+		req, _ := http.NewRequest(http.MethodGet, "/api/tags", nil)
+
+		resp := httptest.NewRecorder()
+		router.ServeHTTP(resp, req)
+
+		var expected, actual map[string]any
+		err := json.Unmarshal([]byte(tc.resp), &expected)
+		if err != nil {
+			t.Fatalf("failed to unmarshal expected response: %v", err)
+		}
+
+		err = json.Unmarshal(resp.Body.Bytes(), &actual)
+		if err != nil {
+			t.Fatalf("failed to unmarshal actual response: %v", err)
+		}
+
+		if !reflect.DeepEqual(expected, actual) {
+			t.Errorf("responses did not match\nExpected: %+v\nActual: %+v", expected, actual)
+		}
+	}
+}
+
+func TestRetrieveMiddleware(t *testing.T) {
+	type testCase struct {
+		name     string
+		endpoint func(c *gin.Context)
+		resp     string
+	}
+
+	testCases := []testCase{
+		{
+			name: "retrieve handler",
+			endpoint: func(c *gin.Context) {
+				c.JSON(http.StatusOK, api.ShowResponse{
+					ModifiedAt: time.Unix(int64(1686935002), 0).UTC(),
+				})
+			},
+			resp: `{
+				"id":"test-model",
+				"object":"model",
+				"created":1686935002,
+				"owned_by":"library"}
+			`,
+		},
+		{
+			name: "retrieve handler error forwarding",
+			endpoint: func(c *gin.Context) {
+				c.JSON(http.StatusBadRequest, gin.H{"error": "model not found"})
+			},
+			resp: `{
+				"error": {
+				  "code": null,
+				  "message": "model not found",
+				  "param": null,
+				  "type": "api_error"
+				}
+			}`,
+		},
+	}
+
+	gin.SetMode(gin.TestMode)
+
+	for _, tc := range testCases {
+		router := gin.New()
+		router.Use(RetrieveMiddleware())
+		router.Handle(http.MethodGet, "/api/show/:model", tc.endpoint)
+		req, _ := http.NewRequest(http.MethodGet, "/api/show/test-model", nil)
+
+		resp := httptest.NewRecorder()
+		router.ServeHTTP(resp, req)
+
+		var expected, actual map[string]any
+		err := json.Unmarshal([]byte(tc.resp), &expected)
+		if err != nil {
+			t.Fatalf("failed to unmarshal expected response: %v", err)
+		}
+
+		err = json.Unmarshal(resp.Body.Bytes(), &actual)
+		if err != nil {
+			t.Fatalf("failed to unmarshal actual response: %v", err)
+		}
+
+		if !reflect.DeepEqual(expected, actual) {
+			t.Errorf("responses did not match\nExpected: %+v\nActual: %+v", expected, actual)
+		}
+	}
+}
diff --git a/openai/openai.go b/openai/openai.go
index 7ef5ac6de..55e55e97c 100644
--- a/openai/openai.go
+++ b/openai/openai.go
@@ -1,21 +1,17 @@
-// openai package provides middleware for partial compatibility with the OpenAI REST API
+// openai package provides core transformation logic for partial compatibility with the OpenAI REST API
 package openai
 
 import (
-	"bytes"
 	"encoding/base64"
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io"
 	"log/slog"
 	"math/rand"
 	"net/http"
 	"strings"
 	"time"
 
-	"github.com/gin-gonic/gin"
-
 	"github.com/ollama/ollama/api"
 	"github.com/ollama/ollama/types/model"
 )
@@ -220,11 +216,12 @@ func NewError(code int, message string) ErrorResponse {
 	return ErrorResponse{Error{Type: etype, Message: message}}
 }
 
-func toUsage(r api.ChatResponse) Usage {
+// ToUsage converts an api.ChatResponse to Usage
+func ToUsage(r api.ChatResponse) Usage {
 	return Usage{
-		PromptTokens:     r.PromptEvalCount,
-		CompletionTokens: r.EvalCount,
-		TotalTokens:      r.PromptEvalCount + r.EvalCount,
+		PromptTokens:     r.Metrics.PromptEvalCount,
+		CompletionTokens: r.Metrics.EvalCount,
+		TotalTokens:      r.Metrics.PromptEvalCount + r.Metrics.EvalCount,
 	}
 }
 
@@ -256,7 +253,8 @@ func toToolCalls(tc []api.ToolCall) []ToolCall {
 	return toolCalls
 }
 
-func toChatCompletion(id string, r api.ChatResponse) ChatCompletion {
+// ToChatCompletion converts an api.ChatResponse to ChatCompletion
+func ToChatCompletion(id string, r api.ChatResponse) ChatCompletion {
 	toolCalls := toToolCalls(r.Message.ToolCalls)
 	return ChatCompletion{
 		Id:                id,
@@ -276,12 +274,13 @@ func toChatCompletion(id string, r api.ChatResponse) ChatCompletion {
 				}
 				return nil
 			}(r.DoneReason),
-		}}, Usage: toUsage(r),
+		}}, Usage: ToUsage(r),
 		DebugInfo: r.DebugInfo,
 	}
 }
 
-func toChunk(id string, r api.ChatResponse, toolCallSent bool) ChatCompletionChunk {
+// ToChunk converts an api.ChatResponse to ChatCompletionChunk
+func ToChunk(id string, r api.ChatResponse, toolCallSent bool) ChatCompletionChunk {
 	toolCalls := toToolCalls(r.Message.ToolCalls)
 	return ChatCompletionChunk{
 		Id:                id,
@@ -305,15 +304,17 @@ func toChunk(id string, r api.ChatResponse, toolCallSent bool) ChatCompletionChu
 	}
 }
 
-func toUsageGenerate(r api.GenerateResponse) Usage {
+// ToUsageGenerate converts an api.GenerateResponse to Usage
+func ToUsageGenerate(r api.GenerateResponse) Usage {
 	return Usage{
-		PromptTokens:     r.PromptEvalCount,
-		CompletionTokens: r.EvalCount,
-		TotalTokens:      r.PromptEvalCount + r.EvalCount,
+		PromptTokens:     r.Metrics.PromptEvalCount,
+		CompletionTokens: r.Metrics.EvalCount,
+		TotalTokens:      r.Metrics.PromptEvalCount + r.Metrics.EvalCount,
 	}
 }
 
-func toCompletion(id string, r api.GenerateResponse) Completion {
+// ToCompletion converts an api.GenerateResponse to Completion
+func ToCompletion(id string, r api.GenerateResponse) Completion {
 	return Completion{
 		Id:                id,
 		Object:            "text_completion",
@@ -330,11 +331,12 @@ func toCompletion(id string, r api.GenerateResponse) Completion {
 				return nil
 			}(r.DoneReason),
 		}},
-		Usage: toUsageGenerate(r),
+		Usage: ToUsageGenerate(r),
 	}
 }
 
-func toCompleteChunk(id string, r api.GenerateResponse) CompletionChunk {
+// ToCompleteChunk converts an api.GenerateResponse to CompletionChunk
+func ToCompleteChunk(id string, r api.GenerateResponse) CompletionChunk {
 	return CompletionChunk{
 		Id:                id,
 		Object:            "text_completion",
@@ -354,7 +356,8 @@ func toCompleteChunk(id string, r api.GenerateResponse) CompletionChunk {
 	}
 }
 
-func toListCompletion(r api.ListResponse) ListCompletion {
+// ToListCompletion converts an api.ListResponse to ListCompletion
+func ToListCompletion(r api.ListResponse) ListCompletion {
 	var data []Model
 	for _, m := range r.Models {
 		data = append(data, Model{
@@ -371,7 +374,8 @@ func toListCompletion(r api.ListResponse) ListCompletion {
 	}
 }
 
-func toEmbeddingList(model string, r api.EmbedResponse) EmbeddingList {
+// ToEmbeddingList converts an api.EmbedResponse to EmbeddingList
+func ToEmbeddingList(model string, r api.EmbedResponse) EmbeddingList {
 	if r.Embeddings != nil {
 		var data []Embedding
 		for i, e := range r.Embeddings {
@@ -396,7 +400,8 @@ func toEmbeddingList(model string, r api.EmbedResponse) EmbeddingList {
 	return EmbeddingList{}
 }
 
-func toModel(r api.ShowResponse, m string) Model {
+// ToModel converts an api.ShowResponse to Model
+func ToModel(r api.ShowResponse, m string) Model {
 	return Model{
 		Id:      m,
 		Object:  "model",
@@ -405,7 +410,8 @@ func toModel(r api.ShowResponse, m string) Model {
 	}
 }
 
-func fromChatRequest(r ChatCompletionRequest) (*api.ChatRequest, error) {
+// FromChatRequest converts a ChatCompletionRequest to api.ChatRequest
+func FromChatRequest(r ChatCompletionRequest) (*api.ChatRequest, error) {
 	var messages []api.Message
 	for _, msg := range r.Messages {
 		toolName := ""
@@ -609,7 +615,8 @@ func fromCompletionToolCall(toolCalls []ToolCall) ([]api.ToolCall, error) {
 	return apiToolCalls, nil
 }
 
-func fromCompleteRequest(r CompletionRequest) (api.GenerateRequest, error) {
+// FromCompleteRequest converts a CompletionRequest to api.GenerateRequest
+func FromCompleteRequest(r CompletionRequest) (api.GenerateRequest, error) {
 	options := make(map[string]any)
 
 	switch stop := r.Stop.(type) {
@@ -660,413 +667,3 @@ func fromCompleteRequest(r CompletionRequest) (api.GenerateRequest, error) {
 		DebugRenderOnly: r.DebugRenderOnly,
 	}, nil
 }
-
-type BaseWriter struct {
-	gin.ResponseWriter
-}
-
-type ChatWriter struct {
-	stream        bool
-	streamOptions *StreamOptions
-	id            string
-	toolCallSent  bool
-	BaseWriter
-}
-
-type CompleteWriter struct {
-	stream        bool
-	streamOptions *StreamOptions
-	id            string
-	BaseWriter
-}
-
-type ListWriter struct {
-	BaseWriter
-}
-
-type RetrieveWriter struct {
-	BaseWriter
-	model string
-}
-
-type EmbedWriter struct {
-	BaseWriter
-	model string
-}
-
-func (w *BaseWriter) writeError(data []byte) (int, error) {
-	var serr api.StatusError
-	err := json.Unmarshal(data, &serr)
-	if err != nil {
-		return 0, err
-	}
-
-	w.ResponseWriter.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w.ResponseWriter).Encode(NewError(http.StatusInternalServerError, serr.Error()))
-	if err != nil {
-		return 0, err
-	}
-
-	return len(data), nil
-}
-
-func (w *ChatWriter) writeResponse(data []byte) (int, error) {
-	var chatResponse api.ChatResponse
-	err := json.Unmarshal(data, &chatResponse)
-	if err != nil {
-		return 0, err
-	}
-
-	// chat chunk
-	if w.stream {
-		c := toChunk(w.id, chatResponse, w.toolCallSent)
-		d, err := json.Marshal(c)
-		if err != nil {
-			return 0, err
-		}
-		if !w.toolCallSent && len(c.Choices) > 0 && len(c.Choices[0].Delta.ToolCalls) > 0 {
-			w.toolCallSent = true
-		}
-
-		w.ResponseWriter.Header().Set("Content-Type", "text/event-stream")
-		_, err = w.ResponseWriter.Write([]byte(fmt.Sprintf("data: %s\n\n", d)))
-		if err != nil {
-			return 0, err
-		}
-
-		if chatResponse.Done {
-			if w.streamOptions != nil && w.streamOptions.IncludeUsage {
-				u := toUsage(chatResponse)
-				c.Usage = &u
-				c.Choices = []ChunkChoice{}
-				d, err := json.Marshal(c)
-				if err != nil {
-					return 0, err
-				}
-				_, err = w.ResponseWriter.Write([]byte(fmt.Sprintf("data: %s\n\n", d)))
-				if err != nil {
-					return 0, err
-				}
-			}
-			_, err = w.ResponseWriter.Write([]byte("data: [DONE]\n\n"))
-			if err != nil {
-				return 0, err
-			}
-		}
-
-		return len(data), nil
-	}
-
-	// chat completion
-	w.ResponseWriter.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w.ResponseWriter).Encode(toChatCompletion(w.id, chatResponse))
-	if err != nil {
-		return 0, err
-	}
-
-	return len(data), nil
-}
-
-func (w *ChatWriter) Write(data []byte) (int, error) {
-	code := w.ResponseWriter.Status()
-	if code != http.StatusOK {
-		return w.writeError(data)
-	}
-
-	return w.writeResponse(data)
-}
-
-func (w *CompleteWriter) writeResponse(data []byte) (int, error) {
-	var generateResponse api.GenerateResponse
-	err := json.Unmarshal(data, &generateResponse)
-	if err != nil {
-		return 0, err
-	}
-
-	// completion chunk
-	if w.stream {
-		c := toCompleteChunk(w.id, generateResponse)
-		if w.streamOptions != nil && w.streamOptions.IncludeUsage {
-			c.Usage = &Usage{}
-		}
-		d, err := json.Marshal(c)
-		if err != nil {
-			return 0, err
-		}
-
-		w.ResponseWriter.Header().Set("Content-Type", "text/event-stream")
-		_, err = w.ResponseWriter.Write([]byte(fmt.Sprintf("data: %s\n\n", d)))
-		if err != nil {
-			return 0, err
-		}
-
-		if generateResponse.Done {
-			if w.streamOptions != nil && w.streamOptions.IncludeUsage {
-				u := toUsageGenerate(generateResponse)
-				c.Usage = &u
-				c.Choices = []CompleteChunkChoice{}
-				d, err := json.Marshal(c)
-				if err != nil {
-					return 0, err
-				}
-				_, err = w.ResponseWriter.Write([]byte(fmt.Sprintf("data: %s\n\n", d)))
-				if err != nil {
-					return 0, err
-				}
-			}
-			_, err = w.ResponseWriter.Write([]byte("data: [DONE]\n\n"))
-			if err != nil {
-				return 0, err
-			}
-		}
-
-		return len(data), nil
-	}
-
-	// completion
-	w.ResponseWriter.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w.ResponseWriter).Encode(toCompletion(w.id, generateResponse))
-	if err != nil {
-		return 0, err
-	}
-
-	return len(data), nil
-}
-
-func (w *CompleteWriter) Write(data []byte) (int, error) {
-	code := w.ResponseWriter.Status()
-	if code != http.StatusOK {
-		return w.writeError(data)
-	}
-
-	return w.writeResponse(data)
-}
-
-func (w *ListWriter) writeResponse(data []byte) (int, error) {
-	var listResponse api.ListResponse
-	err := json.Unmarshal(data, &listResponse)
-	if err != nil {
-		return 0, err
-	}
-
-	w.ResponseWriter.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w.ResponseWriter).Encode(toListCompletion(listResponse))
-	if err != nil {
-		return 0, err
-	}
-
-	return len(data), nil
-}
-
-func (w *ListWriter) Write(data []byte) (int, error) {
-	code := w.ResponseWriter.Status()
-	if code != http.StatusOK {
-		return w.writeError(data)
-	}
-
-	return w.writeResponse(data)
-}
-
-func (w *RetrieveWriter) writeResponse(data []byte) (int, error) {
-	var showResponse api.ShowResponse
-	err := json.Unmarshal(data, &showResponse)
-	if err != nil {
-		return 0, err
-	}
-
-	// retrieve completion
-	w.ResponseWriter.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w.ResponseWriter).Encode(toModel(showResponse, w.model))
-	if err != nil {
-		return 0, err
-	}
-
-	return len(data), nil
-}
-
-func (w *RetrieveWriter) Write(data []byte) (int, error) {
-	code := w.ResponseWriter.Status()
-	if code != http.StatusOK {
-		return w.writeError(data)
-	}
-
-	return w.writeResponse(data)
-}
-
-func (w *EmbedWriter) writeResponse(data []byte) (int, error) {
-	var embedResponse api.EmbedResponse
-	err := json.Unmarshal(data, &embedResponse)
-	if err != nil {
-		return 0, err
-	}
-
-	w.ResponseWriter.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w.ResponseWriter).Encode(toEmbeddingList(w.model, embedResponse))
-	if err != nil {
-		return 0, err
-	}
-
-	return len(data), nil
-}
-
-func (w *EmbedWriter) Write(data []byte) (int, error) {
-	code := w.ResponseWriter.Status()
-	if code != http.StatusOK {
-		return w.writeError(data)
-	}
-
-	return w.writeResponse(data)
-}
-
-func ListMiddleware() gin.HandlerFunc {
-	return func(c *gin.Context) {
-		w := &ListWriter{
-			BaseWriter: BaseWriter{ResponseWriter: c.Writer},
-		}
-
-		c.Writer = w
-
-		c.Next()
-	}
-}
-
-func RetrieveMiddleware() gin.HandlerFunc {
-	return func(c *gin.Context) {
-		var b bytes.Buffer
-		if err := json.NewEncoder(&b).Encode(api.ShowRequest{Name: c.Param("model")}); err != nil {
-			c.AbortWithStatusJSON(http.StatusInternalServerError, NewError(http.StatusInternalServerError, err.Error()))
-			return
-		}
-
-		c.Request.Body = io.NopCloser(&b)
-
-		// response writer
-		w := &RetrieveWriter{
-			BaseWriter: BaseWriter{ResponseWriter: c.Writer},
-			model:      c.Param("model"),
-		}
-
-		c.Writer = w
-
-		c.Next()
-	}
-}
-
-func CompletionsMiddleware() gin.HandlerFunc {
-	return func(c *gin.Context) {
-		var req CompletionRequest
-		err := c.ShouldBindJSON(&req)
-		if err != nil {
-			c.AbortWithStatusJSON(http.StatusBadRequest, NewError(http.StatusBadRequest, err.Error()))
-			return
-		}
-
-		var b bytes.Buffer
-		genReq, err := fromCompleteRequest(req)
-		if err != nil {
-			c.AbortWithStatusJSON(http.StatusBadRequest, NewError(http.StatusBadRequest, err.Error()))
-			return
-		}
-
-		if err := json.NewEncoder(&b).Encode(genReq); err != nil {
-			c.AbortWithStatusJSON(http.StatusInternalServerError, NewError(http.StatusInternalServerError, err.Error()))
-			return
-		}
-
-		c.Request.Body = io.NopCloser(&b)
-
-		w := &CompleteWriter{
-			BaseWriter:    BaseWriter{ResponseWriter: c.Writer},
-			stream:        req.Stream,
-			id:            fmt.Sprintf("cmpl-%d", rand.Intn(999)),
-			streamOptions: req.StreamOptions,
-		}
-
-		c.Writer = w
-		c.Next()
-	}
-}
-
-func EmbeddingsMiddleware() gin.HandlerFunc {
-	return func(c *gin.Context) {
-		var req EmbedRequest
-		err := c.ShouldBindJSON(&req)
-		if err != nil {
-			c.AbortWithStatusJSON(http.StatusBadRequest, NewError(http.StatusBadRequest, err.Error()))
-			return
-		}
-
-		if req.Input == "" {
-			req.Input = []string{""}
-		}
-
-		if req.Input == nil {
-			c.AbortWithStatusJSON(http.StatusBadRequest, NewError(http.StatusBadRequest, "invalid input"))
-			return
-		}
-
-		if v, ok := req.Input.([]any); ok && len(v) == 0 {
-			c.AbortWithStatusJSON(http.StatusBadRequest, NewError(http.StatusBadRequest, "invalid input"))
-			return
-		}
-
-		var b bytes.Buffer
-		if err := json.NewEncoder(&b).Encode(api.EmbedRequest{Model: req.Model, Input: req.Input, Dimensions: req.Dimensions}); err != nil {
-			c.AbortWithStatusJSON(http.StatusInternalServerError, NewError(http.StatusInternalServerError, err.Error()))
-			return
-		}
-
-		c.Request.Body = io.NopCloser(&b)
-
-		w := &EmbedWriter{
-			BaseWriter: BaseWriter{ResponseWriter: c.Writer},
-			model:      req.Model,
-		}
-
-		c.Writer = w
-
-		c.Next()
-	}
-}
-
-func ChatMiddleware() gin.HandlerFunc {
-	return func(c *gin.Context) {
-		var req ChatCompletionRequest
-		err := c.ShouldBindJSON(&req)
-		if err != nil {
-			c.AbortWithStatusJSON(http.StatusBadRequest, NewError(http.StatusBadRequest, err.Error()))
-			return
-		}
-
-		if len(req.Messages) == 0 {
-			c.AbortWithStatusJSON(http.StatusBadRequest, NewError(http.StatusBadRequest, "[] is too short - 'messages'"))
-			return
-		}
-
-		var b bytes.Buffer
-
-		chatReq, err := fromChatRequest(req)
-		if err != nil {
-			c.AbortWithStatusJSON(http.StatusBadRequest, NewError(http.StatusBadRequest, err.Error()))
-			return
-		}
-
-		if err := json.NewEncoder(&b).Encode(chatReq); err != nil {
-			c.AbortWithStatusJSON(http.StatusInternalServerError, NewError(http.StatusInternalServerError, err.Error()))
-			return
-		}
-
-		c.Request.Body = io.NopCloser(&b)
-
-		w := &ChatWriter{
-			BaseWriter:    BaseWriter{ResponseWriter: c.Writer},
-			stream:        req.Stream,
-			id:            fmt.Sprintf("chatcmpl-%d", rand.Intn(999)),
-			streamOptions: req.StreamOptions,
-		}
-
-		c.Writer = w
-
-		c.Next()
-	}
-}
diff --git a/openai/openai_test.go b/openai/openai_test.go
index 0d7f016ba..0f1a877f4 100644
--- a/openai/openai_test.go
+++ b/openai/openai_test.go
@@ -1,19 +1,8 @@
 package openai
 
 import (
-	"bytes"
 	"encoding/base64"
-	"encoding/json"
-	"io"
-	"net/http"
-	"net/http/httptest"
-	"reflect"
-	"strings"
 	"testing"
-	"time"
-
-	"github.com/gin-gonic/gin"
-	"github.com/google/go-cmp/cmp"
 
 	"github.com/ollama/ollama/api"
 )
@@ -23,905 +12,139 @@ const (
 	image  = `iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+A8AAQUBAScY42YAAAAASUVORK5CYII=`
 )
 
-var (
-	False = false
-	True  = true
-)
+func TestFromChatRequest_Basic(t *testing.T) {
+	req := ChatCompletionRequest{
+		Model: "test-model",
+		Messages: []Message{
+			{Role: "user", Content: "Hello"},
+		},
+	}
 
-func captureRequestMiddleware(capturedRequest any) gin.HandlerFunc {
-	return func(c *gin.Context) {
-		bodyBytes, _ := io.ReadAll(c.Request.Body)
-		c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes))
-		err := json.Unmarshal(bodyBytes, capturedRequest)
-		if err != nil {
-			c.AbortWithStatusJSON(http.StatusInternalServerError, "failed to unmarshal request")
-		}
-		c.Next()
+	result, err := FromChatRequest(req)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if result.Model != "test-model" {
+		t.Errorf("expected model 'test-model', got %q", result.Model)
+	}
+
+	if len(result.Messages) != 1 {
+		t.Fatalf("expected 1 message, got %d", len(result.Messages))
+	}
+
+	if result.Messages[0].Role != "user" || result.Messages[0].Content != "Hello" {
+		t.Errorf("unexpected message: %+v", result.Messages[0])
 	}
 }
 
-func TestChatMiddleware(t *testing.T) {
-	type testCase struct {
-		name string
-		body string
-		req  api.ChatRequest
-		err  ErrorResponse
-	}
+func TestFromChatRequest_WithImage(t *testing.T) {
+	imgData, _ := base64.StdEncoding.DecodeString(image)
 
-	var capturedRequest *api.ChatRequest
-
-	testCases := []testCase{
-		{
-			name: "chat handler",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "Hello"}
-				]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "Hello",
+	req := ChatCompletionRequest{
+		Model: "test-model",
+		Messages: []Message{
+			{
+				Role: "user",
+				Content: []any{
+					map[string]any{"type": "text", "text": "Hello"},
+					map[string]any{
+						"type":      "image_url",
+						"image_url": map[string]any{"url": prefix + image},
 					},
 				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &False,
-			},
-		},
-		{
-			name: "chat handler with options",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "Hello"}
-				],
-				"stream":            true,
-				"max_tokens":        999,
-				"seed":              123,
-				"stop":              ["\n", "stop"],
-				"temperature":       3.0,
-				"frequency_penalty": 4.0,
-				"presence_penalty":  5.0,
-				"top_p":             6.0,
-				"response_format":   {"type": "json_object"}
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "Hello",
-					},
-				},
-				Options: map[string]any{
-					"num_predict":       999.0, // float because JSON doesn't distinguish between float and int
-					"seed":              123.0,
-					"stop":              []any{"\n", "stop"},
-					"temperature":       3.0,
-					"frequency_penalty": 4.0,
-					"presence_penalty":  5.0,
-					"top_p":             6.0,
-				},
-				Format: json.RawMessage(`"json"`),
-				Stream: &True,
-			},
-		},
-		{
-			name: "chat handler with streaming usage",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "Hello"}
-				],
-				"stream":            true,
-				"stream_options":    {"include_usage": true},
-				"max_tokens":        999,
-				"seed":              123,
-				"stop":              ["\n", "stop"],
-				"temperature":       3.0,
-				"frequency_penalty": 4.0,
-				"presence_penalty":  5.0,
-				"top_p":             6.0,
-				"response_format":   {"type": "json_object"}
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "Hello",
-					},
-				},
-				Options: map[string]any{
-					"num_predict":       999.0, // float because JSON doesn't distinguish between float and int
-					"seed":              123.0,
-					"stop":              []any{"\n", "stop"},
-					"temperature":       3.0,
-					"frequency_penalty": 4.0,
-					"presence_penalty":  5.0,
-					"top_p":             6.0,
-				},
-				Format: json.RawMessage(`"json"`),
-				Stream: &True,
-			},
-		},
-		{
-			name: "chat handler with image content",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{
-						"role": "user",
-						"content": [
-							{
-								"type": "text",
-								"text": "Hello"
-							},
-							{
-								"type": "image_url",
-								"image_url": {
-									"url": "` + prefix + image + `"
-								}
-							}
-						]
-					}
-				]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "Hello",
-					},
-					{
-						Role: "user",
-						Images: []api.ImageData{
-							func() []byte {
-								img, _ := base64.StdEncoding.DecodeString(image)
-								return img
-							}(),
-						},
-					},
-				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &False,
-			},
-		},
-		{
-			name: "chat handler with tools",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "What's the weather like in Paris Today?"},
-					{"role": "assistant", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]}
-				]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "What's the weather like in Paris Today?",
-					},
-					{
-						Role: "assistant",
-						ToolCalls: []api.ToolCall{
-							{
-								Function: api.ToolCallFunction{
-									Name: "get_current_weather",
-									Arguments: map[string]any{
-										"location": "Paris, France",
-										"format":   "celsius",
-									},
-								},
-							},
-						},
-					},
-				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &False,
-			},
-		},
-		{
-			name: "chat handler with tools and content",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "What's the weather like in Paris Today?"},
-					{"role": "assistant", "content": "Let's see what the weather is like in Paris", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]}
-				]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "What's the weather like in Paris Today?",
-					},
-					{
-						Role:    "assistant",
-						Content: "Let's see what the weather is like in Paris",
-						ToolCalls: []api.ToolCall{
-							{
-								Function: api.ToolCallFunction{
-									Name: "get_current_weather",
-									Arguments: map[string]any{
-										"location": "Paris, France",
-										"format":   "celsius",
-									},
-								},
-							},
-						},
-					},
-				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &False,
-			},
-		},
-		{
-			name: "chat handler with tools and empty content",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "What's the weather like in Paris Today?"},
-					{"role": "assistant", "content": "", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]}
-				]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "What's the weather like in Paris Today?",
-					},
-					{
-						Role: "assistant",
-						ToolCalls: []api.ToolCall{
-							{
-								Function: api.ToolCallFunction{
-									Name: "get_current_weather",
-									Arguments: map[string]any{
-										"location": "Paris, France",
-										"format":   "celsius",
-									},
-								},
-							},
-						},
-					},
-				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &False,
-			},
-		},
-		{
-			name: "chat handler with tools and thinking content",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "What's the weather like in Paris Today?"},
-					{"role": "assistant", "reasoning": "Let's see what the weather is like in Paris", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]}
-				]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "What's the weather like in Paris Today?",
-					},
-					{
-						Role:     "assistant",
-						Thinking: "Let's see what the weather is like in Paris",
-						ToolCalls: []api.ToolCall{
-							{
-								Function: api.ToolCallFunction{
-									Name: "get_current_weather",
-									Arguments: map[string]any{
-										"location": "Paris, France",
-										"format":   "celsius",
-									},
-								},
-							},
-						},
-					},
-				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &False,
-			},
-		},
-		{
-			name: "tool response with call ID",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "What's the weather like in Paris Today?"},
-					{"role": "assistant", "tool_calls": [{"id": "id_abc", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]},
-					{"role": "tool", "tool_call_id": "id_abc", "content": "The weather in Paris is 20 degrees Celsius"}
-				]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "What's the weather like in Paris Today?",
-					},
-					{
-						Role: "assistant",
-						ToolCalls: []api.ToolCall{
-							{
-								Function: api.ToolCallFunction{
-									Name: "get_current_weather",
-									Arguments: map[string]any{
-										"location": "Paris, France",
-										"format":   "celsius",
-									},
-								},
-							},
-						},
-					},
-					{
-						Role:     "tool",
-						Content:  "The weather in Paris is 20 degrees Celsius",
-						ToolName: "get_current_weather",
-					},
-				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &False,
-			},
-		},
-		{
-			name: "tool response with name",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "What's the weather like in Paris Today?"},
-					{"role": "assistant", "tool_calls": [{"id": "id", "type": "function", "function": {"name": "get_current_weather", "arguments": "{\"location\": \"Paris, France\", \"format\": \"celsius\"}"}}]},
-					{"role": "tool", "name": "get_current_weather", "content": "The weather in Paris is 20 degrees Celsius"}
-				]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "What's the weather like in Paris Today?",
-					},
-					{
-						Role: "assistant",
-						ToolCalls: []api.ToolCall{
-							{
-								Function: api.ToolCallFunction{
-									Name: "get_current_weather",
-									Arguments: map[string]any{
-										"location": "Paris, France",
-										"format":   "celsius",
-									},
-								},
-							},
-						},
-					},
-					{
-						Role:     "tool",
-						Content:  "The weather in Paris is 20 degrees Celsius",
-						ToolName: "get_current_weather",
-					},
-				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &False,
-			},
-		},
-		{
-			name: "chat handler with streaming tools",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": "What's the weather like in Paris?"}
-				],
-				"stream": true,
-				"tools": [{
-					"type": "function",
-					"function": {
-						"name": "get_weather",
-						"description": "Get the current weather",
-						"parameters": {
-							"type": "object",
-							"required": ["location"],
-							"properties": {
-								"location": {
-									"type": "string",
-									"description": "The city and state"
-								},
-								"unit": {
-									"type": "string",
-									"enum": ["celsius", "fahrenheit"]
-								}
-							}
-						}
-					}
-				}]
-			}`,
-			req: api.ChatRequest{
-				Model: "test-model",
-				Messages: []api.Message{
-					{
-						Role:    "user",
-						Content: "What's the weather like in Paris?",
-					},
-				},
-				Tools: []api.Tool{
-					{
-						Type: "function",
-						Function: api.ToolFunction{
-							Name:        "get_weather",
-							Description: "Get the current weather",
-							Parameters: struct {
-								Type       string                      `json:"type"`
-								Defs       any                         `json:"$defs,omitempty"`
-								Items      any                         `json:"items,omitempty"`
-								Required   []string                    `json:"required"`
-								Properties map[string]api.ToolProperty `json:"properties"`
-							}{
-								Type:     "object",
-								Required: []string{"location"},
-								Properties: map[string]api.ToolProperty{
-									"location": {
-										Type:        api.PropertyType{"string"},
-										Description: "The city and state",
-									},
-									"unit": {
-										Type: api.PropertyType{"string"},
-										Enum: []any{"celsius", "fahrenheit"},
-									},
-								},
-							},
-						},
-					},
-				},
-				Options: map[string]any{
-					"temperature": 1.0,
-					"top_p":       1.0,
-				},
-				Stream: &True,
-			},
-		},
-		{
-			name: "chat handler error forwarding",
-			body: `{
-				"model": "test-model",
-				"messages": [
-					{"role": "user", "content": 2}
-				]
-			}`,
-			err: ErrorResponse{
-				Error: Error{
-					Message: "invalid message content type: float64",
-					Type:    "invalid_request_error",
-				},
 			},
 		},
 	}
 
-	endpoint := func(c *gin.Context) {
-		c.Status(http.StatusOK)
+	result, err := FromChatRequest(req)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
 	}
 
-	gin.SetMode(gin.TestMode)
-	router := gin.New()
-	router.Use(ChatMiddleware(), captureRequestMiddleware(&capturedRequest))
-	router.Handle(http.MethodPost, "/api/chat", endpoint)
+	if len(result.Messages) != 2 {
+		t.Fatalf("expected 2 messages, got %d", len(result.Messages))
+	}
 
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			req, _ := http.NewRequest(http.MethodPost, "/api/chat", strings.NewReader(tc.body))
-			req.Header.Set("Content-Type", "application/json")
+	if result.Messages[0].Content != "Hello" {
+		t.Errorf("expected first message content 'Hello', got %q", result.Messages[0].Content)
+	}
 
-			defer func() { capturedRequest = nil }()
+	if len(result.Messages[1].Images) != 1 {
+		t.Fatalf("expected 1 image, got %d", len(result.Messages[1].Images))
+	}
 
-			resp := httptest.NewRecorder()
-			router.ServeHTTP(resp, req)
-
-			var errResp ErrorResponse
-			if resp.Code != http.StatusOK {
-				if err := json.Unmarshal(resp.Body.Bytes(), &errResp); err != nil {
-					t.Fatal(err)
-				}
-				return
-			}
-			if diff := cmp.Diff(&tc.req, capturedRequest); diff != "" {
-				t.Fatalf("requests did not match: %+v", diff)
-			}
-			if diff := cmp.Diff(tc.err, errResp); diff != "" {
-				t.Fatalf("errors did not match for %s:\n%s", tc.name, diff)
-			}
-		})
+	if string(result.Messages[1].Images[0]) != string(imgData) {
+		t.Error("image data mismatch")
 	}
 }
 
-func TestCompletionsMiddleware(t *testing.T) {
-	type testCase struct {
-		name string
-		body string
-		req  api.GenerateRequest
-		err  ErrorResponse
+func TestFromCompleteRequest_Basic(t *testing.T) {
+	temp := float32(0.8)
+	req := CompletionRequest{
+		Model:       "test-model",
+		Prompt:      "Hello",
+		Temperature: &temp,
 	}
 
-	var capturedRequest *api.GenerateRequest
-
-	testCases := []testCase{
-		{
-			name: "completions handler",
-			body: `{
-				"model": "test-model",
-				"prompt": "Hello",
-				"temperature": 0.8,
-				"stop": ["\n", "stop"],
-				"suffix": "suffix"
-			}`,
-			req: api.GenerateRequest{
-				Model:  "test-model",
-				Prompt: "Hello",
-				Options: map[string]any{
-					"frequency_penalty": 0.0,
-					"presence_penalty":  0.0,
-					"temperature":       0.8,
-					"top_p":             1.0,
-					"stop":              []any{"\n", "stop"},
-				},
-				Suffix: "suffix",
-				Stream: &False,
-			},
-		},
-		{
-			name: "completions handler stream",
-			body: `{
-				"model": "test-model",
-				"prompt": "Hello",
-				"stream": true,
-				"temperature": 0.8,
-				"stop": ["\n", "stop"],
-				"suffix": "suffix"
-			}`,
-			req: api.GenerateRequest{
-				Model:  "test-model",
-				Prompt: "Hello",
-				Options: map[string]any{
-					"frequency_penalty": 0.0,
-					"presence_penalty":  0.0,
-					"temperature":       0.8,
-					"top_p":             1.0,
-					"stop":              []any{"\n", "stop"},
-				},
-				Suffix: "suffix",
-				Stream: &True,
-			},
-		},
-		{
-			name: "completions handler stream with usage",
-			body: `{
-				"model": "test-model",
-				"prompt": "Hello",
-				"stream": true,
-				"stream_options": {"include_usage": true},
-				"temperature": 0.8,
-				"stop": ["\n", "stop"],
-				"suffix": "suffix"
-			}`,
-			req: api.GenerateRequest{
-				Model:  "test-model",
-				Prompt: "Hello",
-				Options: map[string]any{
-					"frequency_penalty": 0.0,
-					"presence_penalty":  0.0,
-					"temperature":       0.8,
-					"top_p":             1.0,
-					"stop":              []any{"\n", "stop"},
-				},
-				Suffix: "suffix",
-				Stream: &True,
-			},
-		},
-		{
-			name: "completions handler error forwarding",
-			body: `{
-				"model": "test-model",
-				"prompt": "Hello",
-				"temperature": null,
-				"stop": [1, 2],
-				"suffix": "suffix"
-			}`,
-			err: ErrorResponse{
-				Error: Error{
-					Message: "invalid type for 'stop' field: float64",
-					Type:    "invalid_request_error",
-				},
-			},
-		},
+	result, err := FromCompleteRequest(req)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
 	}
 
-	endpoint := func(c *gin.Context) {
-		c.Status(http.StatusOK)
+	if result.Model != "test-model" {
+		t.Errorf("expected model 'test-model', got %q", result.Model)
 	}
 
-	gin.SetMode(gin.TestMode)
-	router := gin.New()
-	router.Use(CompletionsMiddleware(), captureRequestMiddleware(&capturedRequest))
-	router.Handle(http.MethodPost, "/api/generate", endpoint)
+	if result.Prompt != "Hello" {
+		t.Errorf("expected prompt 'Hello', got %q", result.Prompt)
+	}
 
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			req, _ := http.NewRequest(http.MethodPost, "/api/generate", strings.NewReader(tc.body))
-			req.Header.Set("Content-Type", "application/json")
-
-			resp := httptest.NewRecorder()
-			router.ServeHTTP(resp, req)
-
-			var errResp ErrorResponse
-			if resp.Code != http.StatusOK {
-				if err := json.Unmarshal(resp.Body.Bytes(), &errResp); err != nil {
-					t.Fatal(err)
-				}
-			}
-
-			if capturedRequest != nil && !reflect.DeepEqual(tc.req, *capturedRequest) {
-				t.Fatal("requests did not match")
-			}
-
-			if !reflect.DeepEqual(tc.err, errResp) {
-				t.Fatal("errors did not match")
-			}
-
-			capturedRequest = nil
-		})
+	if tempVal, ok := result.Options["temperature"].(float32); !ok || tempVal != 0.8 {
+		t.Errorf("expected temperature 0.8, got %v", result.Options["temperature"])
 	}
 }
 
-func TestEmbeddingsMiddleware(t *testing.T) {
-	type testCase struct {
-		name string
-		body string
-		req  api.EmbedRequest
-		err  ErrorResponse
-	}
-
-	var capturedRequest *api.EmbedRequest
-
-	testCases := []testCase{
-		{
-			name: "embed handler single input",
-			body: `{
-				"input": "Hello",
-				"model": "test-model"
-			}`,
-			req: api.EmbedRequest{
-				Input: "Hello",
-				Model: "test-model",
-			},
-		},
-		{
-			name: "embed handler batch input",
-			body: `{
-				"input": ["Hello", "World"],
-				"model": "test-model"
-			}`,
-			req: api.EmbedRequest{
-				Input: []any{"Hello", "World"},
-				Model: "test-model",
-			},
-		},
-		{
-			name: "embed handler error forwarding",
-			body: `{
-				"model": "test-model"
-			}`,
-			err: ErrorResponse{
-				Error: Error{
-					Message: "invalid input",
-					Type:    "invalid_request_error",
-				},
-			},
+func TestToUsage(t *testing.T) {
+	resp := api.ChatResponse{
+		Metrics: api.Metrics{
+			PromptEvalCount: 10,
+			EvalCount:       20,
 		},
 	}
 
-	endpoint := func(c *gin.Context) {
-		c.Status(http.StatusOK)
+	usage := ToUsage(resp)
+
+	if usage.PromptTokens != 10 {
+		t.Errorf("expected PromptTokens 10, got %d", usage.PromptTokens)
 	}
 
-	gin.SetMode(gin.TestMode)
-	router := gin.New()
-	router.Use(EmbeddingsMiddleware(), captureRequestMiddleware(&capturedRequest))
-	router.Handle(http.MethodPost, "/api/embed", endpoint)
+	if usage.CompletionTokens != 20 {
+		t.Errorf("expected CompletionTokens 20, got %d", usage.CompletionTokens)
+	}
 
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			req, _ := http.NewRequest(http.MethodPost, "/api/embed", strings.NewReader(tc.body))
-			req.Header.Set("Content-Type", "application/json")
-
-			resp := httptest.NewRecorder()
-			router.ServeHTTP(resp, req)
-
-			var errResp ErrorResponse
-			if resp.Code != http.StatusOK {
-				if err := json.Unmarshal(resp.Body.Bytes(), &errResp); err != nil {
-					t.Fatal(err)
-				}
-			}
-
-			if capturedRequest != nil && !reflect.DeepEqual(tc.req, *capturedRequest) {
-				t.Fatal("requests did not match")
-			}
-
-			if !reflect.DeepEqual(tc.err, errResp) {
-				t.Fatal("errors did not match")
-			}
-
-			capturedRequest = nil
-		})
+	if usage.TotalTokens != 30 {
+		t.Errorf("expected TotalTokens 30, got %d", usage.TotalTokens)
 	}
 }
 
-func TestListMiddleware(t *testing.T) {
-	type testCase struct {
-		name     string
-		endpoint func(c *gin.Context)
-		resp     string
+func TestNewError(t *testing.T) {
+	tests := []struct {
+		code int
+		want string
+	}{
+		{400, "invalid_request_error"},
+		{404, "not_found_error"},
+		{500, "api_error"},
 	}
 
-	testCases := []testCase{
-		{
-			name: "list handler",
-			endpoint: func(c *gin.Context) {
-				c.JSON(http.StatusOK, api.ListResponse{
-					Models: []api.ListModelResponse{
-						{
-							Name:       "test-model",
-							ModifiedAt: time.Unix(int64(1686935002), 0).UTC(),
-						},
-					},
-				})
-			},
-			resp: `{
-				"object": "list",
-				"data": [
-					{
-						"id": "test-model",
-						"object": "model",
-						"created": 1686935002,
-						"owned_by": "library"
-					}
-				]
-			}`,
-		},
-		{
-			name: "list handler empty output",
-			endpoint: func(c *gin.Context) {
-				c.JSON(http.StatusOK, api.ListResponse{})
-			},
-			resp: `{
-				"object": "list",
-				"data": null
-			}`,
-		},
-	}
-
-	gin.SetMode(gin.TestMode)
-
-	for _, tc := range testCases {
-		router := gin.New()
-		router.Use(ListMiddleware())
-		router.Handle(http.MethodGet, "/api/tags", tc.endpoint)
-		req, _ := http.NewRequest(http.MethodGet, "/api/tags", nil)
-
-		resp := httptest.NewRecorder()
-		router.ServeHTTP(resp, req)
-
-		var expected, actual map[string]any
-		err := json.Unmarshal([]byte(tc.resp), &expected)
-		if err != nil {
-			t.Fatalf("failed to unmarshal expected response: %v", err)
+	for _, tt := range tests {
+		result := NewError(tt.code, "test message")
+		if result.Error.Type != tt.want {
+			t.Errorf("NewError(%d) type = %q, want %q", tt.code, result.Error.Type, tt.want)
 		}
-
-		err = json.Unmarshal(resp.Body.Bytes(), &actual)
-		if err != nil {
-			t.Fatalf("failed to unmarshal actual response: %v", err)
-		}
-
-		if !reflect.DeepEqual(expected, actual) {
-			t.Errorf("responses did not match\nExpected: %+v\nActual: %+v", expected, actual)
-		}
-	}
-}
-
-func TestRetrieveMiddleware(t *testing.T) {
-	type testCase struct {
-		name     string
-		endpoint func(c *gin.Context)
-		resp     string
-	}
-
-	testCases := []testCase{
-		{
-			name: "retrieve handler",
-			endpoint: func(c *gin.Context) {
-				c.JSON(http.StatusOK, api.ShowResponse{
-					ModifiedAt: time.Unix(int64(1686935002), 0).UTC(),
-				})
-			},
-			resp: `{
-				"id":"test-model",
-				"object":"model",
-				"created":1686935002,
-				"owned_by":"library"}
-			`,
-		},
-		{
-			name: "retrieve handler error forwarding",
-			endpoint: func(c *gin.Context) {
-				c.JSON(http.StatusBadRequest, gin.H{"error": "model not found"})
-			},
-			resp: `{
-				"error": {
-				  "code": null,
-				  "message": "model not found",
-				  "param": null,
-				  "type": "api_error"
-				}
-			}`,
-		},
-	}
-
-	gin.SetMode(gin.TestMode)
-
-	for _, tc := range testCases {
-		router := gin.New()
-		router.Use(RetrieveMiddleware())
-		router.Handle(http.MethodGet, "/api/show/:model", tc.endpoint)
-		req, _ := http.NewRequest(http.MethodGet, "/api/show/test-model", nil)
-
-		resp := httptest.NewRecorder()
-		router.ServeHTTP(resp, req)
-
-		var expected, actual map[string]any
-		err := json.Unmarshal([]byte(tc.resp), &expected)
-		if err != nil {
-			t.Fatalf("failed to unmarshal expected response: %v", err)
-		}
-
-		err = json.Unmarshal(resp.Body.Bytes(), &actual)
-		if err != nil {
-			t.Fatalf("failed to unmarshal actual response: %v", err)
-		}
-
-		if !reflect.DeepEqual(expected, actual) {
-			t.Errorf("responses did not match\nExpected: %+v\nActual: %+v", expected, actual)
+		if result.Error.Message != "test message" {
+			t.Errorf("NewError(%d) message = %q, want %q", tt.code, result.Error.Message, "test message")
 		}
 	}
 }
diff --git a/server/routes.go b/server/routes.go
index 7e0ba1c60..c7052f1b7 100644
--- a/server/routes.go
+++ b/server/routes.go
@@ -37,8 +37,8 @@ import (
 	"github.com/ollama/ollama/fs/ggml"
 	"github.com/ollama/ollama/llm"
 	"github.com/ollama/ollama/logutil"
+	"github.com/ollama/ollama/middleware"
 	"github.com/ollama/ollama/model/parsers"
-	"github.com/ollama/ollama/openai"
 	"github.com/ollama/ollama/server/internal/client/ollama"
 	"github.com/ollama/ollama/server/internal/registry"
 	"github.com/ollama/ollama/template"
@@ -1449,11 +1449,11 @@ func (s *Server) GenerateRoutes(rc *ollama.Registry) (http.Handler, error) {
 	r.POST("/api/embeddings", s.EmbeddingsHandler)
 
 	// Inference (OpenAI compatibility)
-	r.POST("/v1/chat/completions", openai.ChatMiddleware(), s.ChatHandler)
-	r.POST("/v1/completions", openai.CompletionsMiddleware(), s.GenerateHandler)
-	r.POST("/v1/embeddings", openai.EmbeddingsMiddleware(), s.EmbedHandler)
-	r.GET("/v1/models", openai.ListMiddleware(), s.ListHandler)
-	r.GET("/v1/models/:model", openai.RetrieveMiddleware(), s.ShowHandler)
+	r.POST("/v1/chat/completions", middleware.ChatMiddleware(), s.ChatHandler)
+	r.POST("/v1/completions", middleware.CompletionsMiddleware(), s.GenerateHandler)
+	r.POST("/v1/embeddings", middleware.EmbeddingsMiddleware(), s.EmbedHandler)
+	r.GET("/v1/models", middleware.ListMiddleware(), s.ListHandler)
+	r.GET("/v1/models/:model", middleware.RetrieveMiddleware(), s.ShowHandler)
 
 	if rc != nil {
 		// wrap old with new