diff --git a/API.en.md b/API.en.md
index ccb3e74..7c29663 100644
--- a/API.en.md
+++ b/API.en.md
@@ -18,6 +18,7 @@ Docs: [Overview](README.en.md) / [Architecture](docs/ARCHITECTURE.en.md) / [Depl
 - [OpenAI-Compatible API](#openai-compatible-api)
 - [Claude-Compatible API](#claude-compatible-api)
 - [Gemini-Compatible API](#gemini-compatible-api)
+- [Ollama API](#ollama-api)
 - [Admin API](#admin-api)
 - [Error Payloads](#error-payloads)
 - [cURL Examples](#curl-examples)
@@ -123,6 +124,9 @@ Gemini-compatible clients can also send `x-goog-api-key`, `?key=`, or `?api_key=
 | POST | `/v1beta/models/{model}:streamGenerateContent` | Business | Gemini stream |
 | POST | `/v1/models/{model}:generateContent` | Business | Gemini non-stream compat path |
 | POST | `/v1/models/{model}:streamGenerateContent` | Business | Gemini stream compat path |
+| GET | `/api/version` | None | Ollama version endpoint |
+| GET | `/api/tags` | None | Ollama model list |
+| POST | `/api/show` | None | Ollama model capability query (returns `id` + `capabilities`) |
 | POST | `/admin/login` | None | Admin login |
 | GET | `/admin/verify` | JWT | Verify admin JWT |
 | GET | `/admin/vercel/config` | Admin | Read preconfigured Vercel creds |
@@ -617,6 +621,20 @@ Returns SSE (`text/event-stream`), each chunk as `data: <json>`:
 
 ---
 
+## Ollama API
+
+- `POST /api/show` request body: `{"model":"<model-id>"}`.
+- Response uses lowercase `id` (not `ID`) and includes `capabilities` for Ollama-style clients and strict schemas.
+
+Example response:
+
+```json
+{
+  "id": "deepseek-v4-flash",
+  "capabilities": ["tools", "thinking"]
+}
+```
+
 ## Admin API
 
 ### `POST /admin/login`
diff --git a/API.md b/API.md
index bdfe31b..ff5f6c1 100644
--- a/API.md
+++ b/API.md
@@ -18,6 +18,7 @@
 - [OpenAI 兼容接口](#openai-兼容接口)
 - [Claude 兼容接口](#claude-兼容接口)
 - [Gemini 兼容接口](#gemini-兼容接口)
+- [Ollama 兼容接口](#ollama-兼容接口)
 - [Admin 接口](#admin-接口)
 - [错误响应格式](#错误响应格式)
 - [cURL 示例](#curl-示例)
@@ -125,6 +126,9 @@ Gemini 兼容客户端还可以使用 `x-goog-api-key`、`?key=` 或 `?api_key=`
 | POST | `/v1beta/models/{model}:streamGenerateContent` | 业务 | Gemini 流式 |
 | POST | `/v1/models/{model}:generateContent` | 业务 | Gemini 非流式兼容路径 |
 | POST | `/v1/models/{model}:streamGenerateContent` | 业务 | Gemini 流式兼容路径 |
+| GET | `/api/version` | 无 | Ollama 版本接口 |
+| GET | `/api/tags` | 无 | Ollama 模型列表 |
+| POST | `/api/show` | 无 | Ollama 单模型能力查询（返回 `id` 与 `capabilities`） |
 | POST | `/admin/login` | 无 | 管理登录 |
 | GET | `/admin/verify` | JWT | 校验管理 JWT |
 | GET | `/admin/vercel/config` | Admin | 读取 Vercel 预配置 |
@@ -628,6 +632,20 @@ data: {"type":"message_stop"}
 
 ---
 
+## Ollama 兼容接口
+
+- `POST /api/show` 请求体：`{"model":"<model-id>"}`。
+- 响应字段使用小写 `id`（不是 `ID`），并返回 `capabilities` 数组，便于与 Ollama 风格客户端/严格 schema 对齐。
+
+示例响应：
+
+```json
+{
+  "id": "deepseek-v4-flash",
+  "capabilities": ["tools", "thinking"]
+}
+```
+
 ## Admin 接口
 
 ### `POST /admin/login`
diff --git a/VERSION b/VERSION
index 9e3a933..cbe06cd 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.4.3
+4.4.4
diff --git a/internal/config/models.go b/internal/config/models.go
index f583749..a9c22b0 100644
--- a/internal/config/models.go
+++ b/internal/config/models.go
@@ -1,6 +1,9 @@
 package config
 
-import "strings"
+import (
+	"strings"
+	"time"
+)
 
 type ModelInfo struct {
 	ID         string `json:"id"`
@@ -9,6 +12,16 @@ type ModelInfo struct {
 	OwnedBy    string `json:"owned_by"`
 	Permission []any  `json:"permission,omitempty"`
 }
+type OllamaModelInfo struct {
+	Name       string `json:"name"`
+	Model      string `json:"model"`
+	Size       int64  `json:"size"`
+	ModifiedAt string `json:"modified_at"`
+}
+type OllamaCapabilitiesModelInfo struct {
+	ID           string   `json:"id"`
+	Capabilities []string `json:"capabilities"`
+}
 
 type ModelAliasReader interface {
 	ModelAliases() map[string]string
@@ -24,8 +37,21 @@ var deepSeekBaseModels = []ModelInfo{
 	{ID: "deepseek-v4-vision", Object: "model", Created: 1677610602, OwnedBy: "deepseek", Permission: []any{}},
 }
 
-var DeepSeekModels = appendNoThinkingVariants(deepSeekBaseModels)
+var OllamaCapabilitiesModels = []OllamaCapabilitiesModelInfo{
+	{ID: "deepseek-v4-flash", Capabilities: []string{"tools", "thinking"}},
+	{ID: "deepseek-v4-pro", Capabilities: []string{"tools", "thinking"}},
+	{ID: "deepseek-v4-flash-search", Capabilities: []string{"tools", "thinking"}},
+	{ID: "deepseek-v4-pro-search", Capabilities: []string{"tools", "thinking"}},
+	{ID: "deepseek-v4-vision", Capabilities: []string{"tools", "thinking", "vision"}},
+	{ID: "deepseek-v4-flash-nothinking", Capabilities: []string{"tools"}},
+	{ID: "deepseek-v4-pro-nothinking", Capabilities: []string{"tools"}},
+	{ID: "deepseek-v4-flash-search-nothinking", Capabilities: []string{"tools"}},
+	{ID: "deepseek-v4-pro-search-nothinking", Capabilities: []string{"tools"}},
+	{ID: "deepseek-v4-vision-nothinking", Capabilities: []string{"tools", "vision"}},
+}
 
+var DeepSeekModels = appendNoThinkingVariants(deepSeekBaseModels)
+var OllamaModels = mapToOllamaModels(DeepSeekModels)
 var claudeBaseModels = []ModelInfo{
 	// Current aliases
 	{ID: "claude-opus-4-6", Object: "model", Created: 1715635200, OwnedBy: "anthropic"},
@@ -247,6 +273,23 @@ func OpenAIModelByID(store ModelAliasReader, id string) (ModelInfo, bool) {
 	return ModelInfo{}, false
 }
 
+func OllamaModelsResponse() map[string]any {
+	return map[string]any{"models": OllamaModels}
+}
+
+func OllamaModelByID(store ModelAliasReader, id string) (OllamaCapabilitiesModelInfo, bool) {
+	canonical, ok := ResolveModel(store, id)
+	if !ok {
+		return OllamaCapabilitiesModelInfo{}, false
+	}
+	for _, model := range OllamaCapabilitiesModels {
+		if model.ID == canonical {
+			return model, true
+		}
+	}
+	return OllamaCapabilitiesModelInfo{}, false
+}
+
 func ClaudeModelsResponse() map[string]any {
 	resp := map[string]any{"object": "list", "data": ClaudeModels}
 	if len(ClaudeModels) > 0 {
@@ -270,6 +313,23 @@ func appendNoThinkingVariants(models []ModelInfo) []ModelInfo {
 	}
 	return out
 }
+func mapToOllamaModels(models []ModelInfo) []OllamaModelInfo {
+	out := make([]OllamaModelInfo, 0, len(models))
+	for _, model := range models {
+		var modifiedAt string
+		if model.Created > 0 {
+			modifiedAt = time.Unix(model.Created, 0).Format(time.RFC3339)
+		}
+		ollamaModel := OllamaModelInfo{
+			Name:       model.ID,
+			Model:      model.ID,
+			Size:       0,
+			ModifiedAt: modifiedAt,
+		}
+		out = append(out, ollamaModel)
+	}
+	return out
+}
 
 func splitNoThinkingModel(model string) (string, bool) {
 	model = lower(strings.TrimSpace(model))
diff --git a/internal/config/paths.go b/internal/config/paths.go
index 7b8f22d..60f2829 100644
--- a/internal/config/paths.go
+++ b/internal/config/paths.go
@@ -58,6 +58,11 @@ func RawStreamSampleRoot() string {
 }
 
 func ChatHistoryPath() string {
+	// On Vercel, /var/task is read-only at runtime. If no explicit path is set,
+	// default to /tmp/chat_history.json (the only writable directory).
+	if IsVercel() && strings.TrimSpace(os.Getenv("DS2API_CHAT_HISTORY_PATH")) == "" {
+		return "/tmp/chat_history.json"
+	}
 	return ResolvePath("DS2API_CHAT_HISTORY_PATH", "data/chat_history.json")
 }
 
diff --git a/internal/httpapi/ollama/handler_routes.go b/internal/httpapi/ollama/handler_routes.go
new file mode 100644
index 0000000..fb64a06
--- /dev/null
+++ b/internal/httpapi/ollama/handler_routes.go
@@ -0,0 +1,58 @@
+package ollama
+
+import (
+	"ds2api/internal/config"
+	"ds2api/internal/util"
+	"encoding/json"
+	"github.com/go-chi/chi/v5"
+	"log/slog"
+	"net/http"
+)
+
+var WriteJSON = util.WriteJSON
+
+type ConfigReader interface {
+	ModelAliases() map[string]string
+}
+
+type Handler struct {
+	Store ConfigReader
+}
+
+type OllamaModelRequest struct {
+	Model string `json:"model"`
+}
+
+func RegisterRoutes(r chi.Router, h *Handler) {
+	r.Get("/api/version", h.GetVersion)
+	r.Get("/api/tags", h.ListOllamaModels)
+	r.Post("/api/show", h.GetOllamaModel)
+}
+
+func (h *Handler) GetVersion(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write([]byte(`{"version":"0.23.1"}`))
+}
+func (h *Handler) ListOllamaModels(w http.ResponseWriter, r *http.Request) {
+	WriteJSON(w, http.StatusOK, config.OllamaModelsResponse())
+}
+func (h *Handler) GetOllamaModel(w http.ResponseWriter, r *http.Request) {
+	var payload OllamaModelRequest
+	if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
+		http.Error(w, "Invalid JSON body: "+err.Error(), http.StatusBadRequest)
+		return
+	}
+	defer func() {
+		if err := r.Body.Close(); err != nil {
+			slog.Warn("[ollama] failed to close request body", "error", err)
+		}
+	}()
+	modelID := payload.Model
+	model, ok := config.OllamaModelByID(h.Store, modelID)
+	if !ok {
+		http.Error(w, "Model not found.", http.StatusNotFound)
+		return
+	}
+	WriteJSON(w, http.StatusOK, model)
+}
diff --git a/internal/httpapi/ollama/handler_routes_test.go b/internal/httpapi/ollama/handler_routes_test.go
new file mode 100644
index 0000000..0d22779
--- /dev/null
+++ b/internal/httpapi/ollama/handler_routes_test.go
@@ -0,0 +1,127 @@
+package ollama
+
+import (
+	"encoding/json"
+	"github.com/go-chi/chi/v5"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+type ollamaTestSurface struct {
+	Store   ConfigReader
+	handler *Handler
+}
+
+func (h *ollamaTestSurface) apiHandler() *Handler {
+	if h.handler == nil {
+		h.handler = &Handler{Store: h.Store}
+	}
+	return h.handler
+}
+
+func registerOllamaTestRoutes(r chi.Router, h *ollamaTestSurface) {
+	r.Get("/api/version", h.apiHandler().GetVersion)
+	r.Get("/api/tags", h.apiHandler().ListOllamaModels)
+	r.Post("/api/show", h.apiHandler().GetOllamaModel)
+}
+
+func TestGetOllamaVersionRoute(t *testing.T) {
+	h := &ollamaTestSurface{}
+	r := chi.NewRouter()
+	registerOllamaTestRoutes(r, h)
+	req := httptest.NewRequest(http.MethodGet, "/api/version", nil)
+	rec := httptest.NewRecorder()
+	r.ServeHTTP(rec, req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+	}
+}
+
+func TestGetOllamaModelsRoute(t *testing.T) {
+	h := &ollamaTestSurface{}
+	r := chi.NewRouter()
+	registerOllamaTestRoutes(r, h)
+	req := httptest.NewRequest(http.MethodGet, "/api/tags", nil)
+	rec := httptest.NewRecorder()
+	r.ServeHTTP(rec, req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+	}
+}
+
+func TestGetOllamaModelRoute(t *testing.T) {
+	h := &ollamaTestSurface{}
+	r := chi.NewRouter()
+	registerOllamaTestRoutes(r, h)
+
+	t.Run("direct", func(t *testing.T) {
+		body := `{"model":"deepseek-v4-flash"}`
+		req := httptest.NewRequest(http.MethodPost, "/api/show", strings.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+		rec := httptest.NewRecorder()
+		r.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+		}
+		var payload map[string]any
+		if err := json.Unmarshal(rec.Body.Bytes(), &payload); err != nil {
+			t.Fatalf("expected valid json body, got err=%v body=%s", err, rec.Body.String())
+		}
+		if _, ok := payload["id"]; !ok {
+			t.Fatalf("expected response has lowercase id field, body=%s", rec.Body.String())
+		}
+		if _, ok := payload["ID"]; ok {
+			t.Fatalf("expected response does not expose uppercase ID field, body=%s", rec.Body.String())
+		}
+	})
+
+	t.Run("direct_nothinking", func(t *testing.T) {
+		body := `{"model":"deepseek-v4-flash-nothinking"}`
+		req := httptest.NewRequest(http.MethodPost, "/api/show", strings.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+		rec := httptest.NewRecorder()
+		r.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+		}
+	})
+
+	t.Run("direct_expert", func(t *testing.T) {
+		body := `{"model":"deepseek-v4-pro"}`
+		req := httptest.NewRequest(http.MethodPost, "/api/show", strings.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+		rec := httptest.NewRecorder()
+		r.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+		}
+	})
+
+	t.Run("direct_vision", func(t *testing.T) {
+		body := `{"model":"deepseek-v4-vision"}`
+		req := httptest.NewRequest(http.MethodPost, "/api/show", strings.NewReader(body))
+		req.Header.Set("Content-Type", "application/json")
+		rec := httptest.NewRecorder()
+		r.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("expected 200, got %d body=%s", rec.Code, rec.Body.String())
+		}
+	})
+}
+
+func TestGetOllamaModelRouteNotFound(t *testing.T) {
+	h := &ollamaTestSurface{}
+	r := chi.NewRouter()
+	registerOllamaTestRoutes(r, h)
+
+	body := `{"model":"not-exists"}`
+	req := httptest.NewRequest(http.MethodPost, "/api/show", strings.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	r.ServeHTTP(rec, req)
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d body=%s", rec.Code, rec.Body.String())
+	}
+}
diff --git a/internal/server/router.go b/internal/server/router.go
index 7ec7eef..07b5e15 100644
--- a/internal/server/router.go
+++ b/internal/server/router.go
@@ -22,6 +22,7 @@ import (
 	"ds2api/internal/httpapi/admin"
 	"ds2api/internal/httpapi/claude"
 	"ds2api/internal/httpapi/gemini"
+	"ds2api/internal/httpapi/ollama"
 	"ds2api/internal/httpapi/openai/chat"
 	"ds2api/internal/httpapi/openai/embeddings"
 	"ds2api/internal/httpapi/openai/files"
@@ -68,6 +69,7 @@ func NewApp() (*App, error) {
 	claudeHandler := &claude.Handler{Store: store, Auth: resolver, DS: dsClient, OpenAI: chatHandler, ChatHistory: chatHistoryStore}
 	geminiHandler := &gemini.Handler{Store: store, Auth: resolver, DS: dsClient, OpenAI: chatHandler, ChatHistory: chatHistoryStore}
 	adminHandler := &admin.Handler{Store: store, Pool: pool, DS: dsClient, OpenAI: chatHandler, ChatHistory: chatHistoryStore}
+	ollamaHandler := &ollama.Handler{Store: store}
 	webuiHandler := webui.NewHandler()
 
 	r := chi.NewRouter()
@@ -112,6 +114,7 @@ func NewApp() (*App, error) {
 	r.Post("/embeddings", embeddingsHandler.Embeddings)
 	claude.RegisterRoutes(r, claudeHandler)
 	gemini.RegisterRoutes(r, geminiHandler)
+	ollama.RegisterRoutes(r, ollamaHandler)
 	r.Route("/admin", func(ar chi.Router) {
 		admin.RegisterRoutes(ar, adminHandler)
 	})