diff --git a/conf/models/volcengine.json b/conf/models/volcengine.json
index c260154c9..e4200ce57 100644
--- a/conf/models/volcengine.json
+++ b/conf/models/volcengine.json
@@ -14,7 +14,11 @@
       "max_tokens": 262144,
       "model_types": [
         "chat"
-      ]
+      ],
+      "thinking": {
+        "default_value": true,
+        "clear_thinking": true
+      }
     }
   ]
 }
\ No newline at end of file
diff --git a/internal/entity/models/volcengine.go b/internal/entity/models/volcengine.go
index f203412ca..c18985436 100644
--- a/internal/entity/models/volcengine.go
+++ b/internal/entity/models/volcengine.go
@@ -17,9 +17,14 @@
 package models
 
 import (
+	"bufio"
+	"bytes"
+	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
+	"ragflow/internal/logger"
+	"strings"
 	"time"
 )
 
@@ -53,7 +58,152 @@ func (z *VolcEngine) Name() string {
 
 // Chat sends a message and returns response
 func (z *VolcEngine) Chat(modelName, message *string, apiConfig *APIConfig, modelConfig *ChatConfig) (*ChatResponse, error) {
-	return nil, fmt.Errorf("%s, no such method", z.Name())
+	if message == nil {
+		return nil, fmt.Errorf("message is nil")
+	}
+
+	var region = "default"
+	if apiConfig.Region != nil {
+		region = *apiConfig.Region
+	}
+
+	url := fmt.Sprintf("%s/%s", z.BaseURL[region], z.URLSuffix.Chat)
+
+	//Build request body
+	reqBody := map[string]interface{}{
+		"model": modelName,
+		"messages": []map[string]string{
+			{"role": "user", "content": *message},
+		},
+		"stream":      false,
+		"temperature": 1,
+	}
+
+	if modelConfig.Stream != nil {
+		reqBody["stream"] = *modelConfig.Stream
+	}
+
+	if modelConfig.MaxTokens != nil {
+		reqBody["max_tokens"] = *modelConfig.MaxTokens
+	}
+
+	if modelConfig.Temperature != nil {
+		reqBody["temperature"] = *modelConfig.Temperature
+	}
+
+	if modelConfig.TopP != nil {
+		reqBody["top_p"] = *modelConfig.TopP
+	}
+	// TODO VolcEngine has `auto` mode
+	if modelConfig.Thinking != nil {
+		if *modelConfig.Thinking {
+			var thinkingFlag string
+			switch *modelConfig.Effort {
+			case "none", "minimal":
+				thinkingFlag = "disabled"
+				reqBody["reasoning_effort"] = "minimal"
+				break
+			case "low":
+				thinkingFlag = "enabled"
+				reqBody["reasoning_effort"] = "low"
+				break
+			case "medium":
+				thinkingFlag = "enabled"
+				reqBody["reasoning_effort"] = "medium"
+				break
+			case "auto", "default":
+				thinkingFlag = "enabled"
+				reqBody["reasoning_effort"] = "medium"
+				break
+			case "high":
+				thinkingFlag = "enabled"
+				reqBody["reasoning_effort"] = "high"
+				break
+			default:
+				return nil, fmt.Errorf("invalid effort level")
+			}
+			reqBody["thinking"] = map[string]interface{}{
+				"type": thinkingFlag,
+			}
+		} else {
+			reqBody["thinking"] = map[string]interface{}{
+				"type": "disabled",
+			}
+		}
+	}
+
+	jsonData, err := json.Marshal(reqBody)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal request: %w", err)
+	}
+
+	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))
+
+	resp, err := z.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to send request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("API request failed with status %d: %s", resp.StatusCode, string(body))
+	}
+
+	// Parse response
+	var result map[string]interface{}
+	if err = json.Unmarshal(body, &result); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal response: %w", err)
+	}
+
+	choices, ok := result["choices"].([]interface{})
+	if !ok || len(choices) == 0 {
+		return nil, fmt.Errorf("no choices in responses")
+	}
+
+	firstChoice, ok := choices[0].(map[string]interface{})
+	if !ok {
+		return nil, fmt.Errorf("invalid choice format")
+	}
+
+	messageMap, ok := firstChoice["message"].(map[string]interface{})
+	if !ok {
+		return nil, fmt.Errorf("invalid message format")
+	}
+
+	content, ok := messageMap["content"].(string)
+	if !ok {
+		return nil, fmt.Errorf("invalid content format")
+	}
+
+	var reasonContent string
+	if modelConfig.Thinking != nil && *modelConfig.Thinking {
+		reasonContent, ok = messageMap["reasoning_content"].(string)
+		if !ok {
+			return nil, fmt.Errorf("invalid reasonContent format")
+		}
+		// if first char of reasonContent is \n remove the \n
+		if reasonContent != "" && reasonContent[0] == '\n' {
+			reasonContent = reasonContent[1:]
+		}
+	}
+
+	chatResponse := &ChatResponse{
+		Answer:        &content,
+		ReasonContent: &reasonContent,
+	}
+
+	return chatResponse, nil
 }
 
 // ChatWithMessages sends multiple messages with roles and returns response
@@ -63,7 +213,177 @@ func (z *VolcEngine) ChatWithMessages(modelName string, apiKey *string, messages
 
 // ChatStreamlyWithSender sends a message and streams response via sender function (best performance, no channel)
 func (z *VolcEngine) ChatStreamlyWithSender(modelName, message *string, apiConfig *APIConfig, modelConfig *ChatConfig, sender func(*string, *string) error) error {
-	return fmt.Errorf("%s, no such method", z.Name())
+	var region = "default"
+
+	if apiConfig.Region != nil {
+		region = *apiConfig.Region
+	}
+
+	url := fmt.Sprintf("%s/chat/completions", z.BaseURL[region])
+
+	// Build request body with streaming enabled
+	reqBody := map[string]interface{}{
+		"model": modelName,
+		"messages": []map[string]interface{}{
+			{"role": "user", "content": *message},
+		},
+		"stream":      true,
+		"temperature": 1,
+	}
+
+	if modelConfig.Stream != nil {
+		reqBody["stream"] = *modelConfig.Stream
+	}
+
+	if modelConfig.MaxTokens != nil {
+		reqBody["max_tokens"] = *modelConfig.MaxTokens
+	}
+
+	if modelConfig.Temperature != nil {
+		reqBody["temperature"] = *modelConfig.Temperature
+	}
+
+	if modelConfig.TopP != nil {
+		reqBody["top_p"] = *modelConfig.TopP
+	}
+
+	if modelConfig.DoSample != nil {
+		reqBody["do_sample"] = *modelConfig.DoSample
+	}
+
+	if modelConfig.Stop != nil {
+		reqBody["stop"] = *modelConfig.Stop
+	}
+
+	// TODO VolcEngine has `auto` mode
+	if modelConfig.Thinking != nil {
+		if *modelConfig.Thinking {
+			var thinkingFlag string
+			switch *modelConfig.Effort {
+			case "none", "minimal":
+				thinkingFlag = "disabled"
+				reqBody["reasoning_effort"] = "minimal"
+				break
+			case "low":
+				thinkingFlag = "enabled"
+				reqBody["reasoning_effort"] = "low"
+				break
+			case "medium":
+				thinkingFlag = "enabled"
+				reqBody["reasoning_effort"] = "medium"
+				break
+			case "auto", "default":
+				thinkingFlag = "enabled"
+				reqBody["reasoning_effort"] = "medium"
+				break
+			case "high":
+				thinkingFlag = "enabled"
+				reqBody["reasoning_effort"] = "high"
+				break
+			default:
+				return fmt.Errorf("invalid effort level")
+			}
+			reqBody["thinking"] = map[string]interface{}{
+				"type": thinkingFlag,
+			}
+		} else {
+			reqBody["thinking"] = map[string]interface{}{
+				"type": "disabled",
+			}
+		}
+	}
+
+	jsonData, err := json.Marshal(reqBody)
+	if err != nil {
+		return fmt.Errorf("failed to marshal request: %w", err)
+	}
+
+	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))
+
+	resp, err := z.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to send request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("API request failed with status %d: %s", resp.StatusCode, string(body))
+	}
+
+	// SSE parsing: read line by line
+	scanner := bufio.NewScanner(resp.Body)
+	for scanner.Scan() {
+		line := scanner.Text()
+		logger.Info(line)
+
+		// SSE data line start with data:
+		if !strings.HasPrefix(line, "data:") {
+			continue
+		}
+
+		// Extract JSON after data:
+		data := strings.TrimSpace(line[5:])
+
+		// [DONE] marks the end of stream
+		if data == "[DONE]" {
+			break
+		}
+
+		// Parse the JSON event
+		var event map[string]interface{}
+		if err := json.Unmarshal([]byte(data), &event); err != nil {
+			continue
+		}
+
+		choices, ok := event["choices"].([]interface{})
+		if !ok || len(choices) == 0 {
+			continue
+		}
+
+		firstChoice, ok := choices[0].(map[string]interface{})
+		if !ok {
+			continue
+		}
+
+		delta, ok := firstChoice["delta"].(map[string]interface{})
+		if !ok {
+			continue
+		}
+
+		content, ok := delta["content"].(string)
+		if ok || content != "" {
+			if err := sender(&content, nil); err != nil {
+				return err
+			}
+		}
+
+		reasoningContent, ok := delta["reasoning_content"].(string)
+		if ok && reasoningContent != "" {
+			if err := sender(nil, &reasoningContent); err != nil {
+				return err
+			}
+		}
+
+		finishReason, ok := firstChoice["finish_reason"].(string)
+		if ok && finishReason != "" {
+			break
+		}
+	}
+
+	// Send [DONE] marker for OpenAI compatibility
+	endOfStream := "[DONE]"
+	if err = sender(&endOfStream, nil); err != nil {
+		return err
+	}
+
+	return scanner.Err()
 }
 
 // Encode encodes a list of texts into embeddings