feat: real SSE streaming for agent chat + data cleanup on startup

SSE Streaming:
- Add POST /api/agent/chat/stream endpoint with real SSE streaming
- Agent.HandleMessageStream() streams final LLM response via onEvent callback
- Tool-calling rounds use non-streaming; tool status sent as 'tool' events
- Frontend uses ReadableStream API instead of fake word-by-word setTimeout
- SSE events: tool (tool execution), delta (text chunk), done (complete), error

Data Maintenance:
- Add cleanupOldData() on server startup (decisions >90d, equity >180d)
- Add CleanOldRecords to DecisionStore and EquityStore
- Add store-level logger for cleanup operations

Exchange Traders:
- Add GetAccountInfo() to Bitget, Bybit, Indodax, KuCoin, Lighter, OKX traders
- Remove unused imports in Aster/Lighter traders

agent/agent.go

@@ -151,6 +151,45 @@ func (a *Agent) HandleMessage(ctx context.Context, userID int64, text string) (s
 	return a.thinkAndAct(ctx, userID, lang, text)
 }
 
+// HandleMessageStream is like HandleMessage but streams the final LLM response via SSE.
+// onEvent is called with (eventType, data) — see StreamEvent* constants.
+// Non-streamable responses (commands, trade confirmations) return immediately without events.
+func (a *Agent) HandleMessageStream(ctx context.Context, userID int64, text string, onEvent func(event, data string)) (string, error) {
+	lang := a.config.Language
+	if strings.HasPrefix(text, "[lang:") {
+		if end := strings.Index(text, "] "); end > 0 {
+			lang = text[6:end]; text = text[end+2:]
+		}
+	}
+
+	a.logger.Info("message (stream)", "user_id", userID, "text", text)
+
+	if resp, handled := a.handleSetupFlow(userID, text, lang); handled {
+		return resp, nil
+	}
+	if text == "/help" || text == "/start" {
+		return a.msg(lang, "help"), nil
+	}
+	if text == "/status" {
+		return a.handleStatus(lang), nil
+	}
+	if text == "/clear" {
+		a.history.Clear(userID)
+		if lang == "zh" { return "🧹 对话记忆已清除。", nil }
+		return "🧹 Conversation history cleared.", nil
+	}
+	if resp, handled := a.handleTradeConfirmation(ctx, userID, text, lang); handled {
+		return resp, nil
+	}
+	if trade := parseTradeCommand(text); trade != nil {
+		a.pending.Add(trade)
+		a.pending.CleanExpired()
+		return formatTradeConfirmation(trade, lang), nil
+	}
+
+	return a.thinkAndActStream(ctx, userID, lang, text, onEvent)
+}
+
 // thinkAndAct sends the user message to LLM with full context and tools.
 // The LLM decides what to do — analyze, query, trade, or just chat.
 // Supports a tool-calling loop: LLM can call tools, get results, and continue.
@@ -263,6 +302,94 @@ func (a *Agent) thinkAndAct(ctx context.Context, userID int64, lang, text string
 	return finalResp, nil
 }
 
+// StreamEvent types sent via SSE to the frontend.
+const (
+	StreamEventTool  = "tool"  // Tool is being called (shows status to user)
+	StreamEventDelta = "delta" // Text chunk from LLM streaming
+	StreamEventDone  = "done"  // Stream complete
+	StreamEventError = "error" // Error occurred
+)
+
+// thinkAndActStream is like thinkAndAct but streams the final LLM response via SSE.
+// Tool-calling rounds use non-streaming CallWithRequestFull.
+// Once tools are done, the final response is streamed via onEvent("delta", accumulated_text).
+// onEvent("tool", toolName) is sent when a tool is being called.
+func (a *Agent) thinkAndActStream(ctx context.Context, userID int64, lang, text string, onEvent func(event, data string)) (string, error) {
+	if a.aiClient == nil {
+		return a.noAIFallback(lang, text)
+	}
+
+	systemPrompt := a.buildSystemPrompt(lang)
+	enrichment := a.gatherContext(text)
+	userPrompt := text
+	if enrichment != "" {
+		userPrompt = text + "\n\n---\n[NOFXi System Context - real-time data for reference]\n" + enrichment
+	}
+
+	messages := []mcp.Message{mcp.NewSystemMessage(systemPrompt)}
+	for _, msg := range a.history.Get(userID) {
+		messages = append(messages, mcp.NewMessage(msg.Role, msg.Content))
+	}
+	messages = append(messages, mcp.NewUserMessage(userPrompt))
+	a.history.Add(userID, "user", text)
+
+	tools := agentTools()
+
+	// Tool-calling loop: use non-streaming to detect tool calls.
+	// Once no tool calls remain, stream the final response for real-time UX.
+	const maxToolRounds = 5
+	toolsUsed := false
+	for round := 0; round < maxToolRounds; round++ {
+		req := &mcp.Request{Messages: messages, Tools: tools, ToolChoice: "auto"}
+		resp, err := a.aiClient.CallWithRequestFull(req)
+		if err != nil {
+			a.logger.Error("LLM call failed (stream)", "error", err, "round", round)
+			return a.noAIFallback(lang, text)
+		}
+
+		// No tool calls → final text response
+		if len(resp.ToolCalls) == 0 {
+			if !toolsUsed {
+				// No tools at all — response was fast, just return it
+				a.history.Add(userID, "assistant", resp.Content)
+				return resp.Content, nil
+			}
+			// After tool rounds, we already have the response (non-streamed).
+			// Still return it — the SSE handler sends it as "done".
+			a.history.Add(userID, "assistant", resp.Content)
+			return resp.Content, nil
+		}
+
+		// Process tool calls
+		toolsUsed = true
+		a.logger.Info("LLM tool calls (stream)", "count", len(resp.ToolCalls), "round", round)
+		assistantMsg := mcp.Message{Role: "assistant", ToolCalls: resp.ToolCalls}
+		if resp.Content != "" {
+			assistantMsg.Content = resp.Content
+		}
+		messages = append(messages, assistantMsg)
+
+		for _, tc := range resp.ToolCalls {
+			onEvent(StreamEventTool, tc.Function.Name)
+			a.logger.Info("executing tool", "name", tc.Function.Name, "call_id", tc.ID)
+			result := a.handleToolCall(ctx, userID, lang, tc)
+			messages = append(messages, mcp.Message{Role: "tool", Content: result, ToolCallID: tc.ID})
+		}
+	}
+
+	// Exhausted tool rounds — stream the final synthesis response
+	finalReq := &mcp.Request{Messages: messages}
+	finalText, err := a.aiClient.CallWithRequestStream(finalReq, func(chunk string) {
+		onEvent(StreamEventDelta, chunk)
+	})
+	if err != nil {
+		a.logger.Error("stream final response failed", "error", err)
+		return a.noAIFallback(lang, text)
+	}
+	a.history.Add(userID, "assistant", finalText)
+	return finalText, nil
+}
+
 // buildSystemPrompt creates the system prompt that makes NOFXi behave like a real agent.
 func (a *Agent) buildSystemPrompt(lang string) string {
 	// Gather live system state

agent/web.go

@@ -83,6 +83,78 @@ func (w *WebHandler) HandleChat(rw http.ResponseWriter, r *http.Request) {
 	writeJSON(rw, 200, map[string]string{"response": resp})
 }
 
+// HandleChatStream handles POST /api/agent/chat/stream — SSE streaming chat.
+// Sends server-sent events with types: tool, delta, done, error.
+func (w *WebHandler) HandleChatStream(rw http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(rw, "method not allowed", 405)
+		return
+	}
+	var req struct {
+		Message string `json:"message"`
+		UserID  int64  `json:"user_id"`
+		Lang    string `json:"lang"`
+	}
+	if err := json.NewDecoder(io.LimitReader(r.Body, 64*1024)).Decode(&req); err != nil {
+		writeJSON(rw, 400, map[string]string{"error": "invalid request"})
+		return
+	}
+	if req.Message == "" {
+		writeJSON(rw, 400, map[string]string{"error": "message required"})
+		return
+	}
+	if req.UserID == 0 {
+		req.UserID = 1
+	}
+	msg := req.Message
+	if req.Lang != "" {
+		msg = "[lang:" + req.Lang + "] " + msg
+	}
+
+	// Set SSE headers
+	rw.Header().Set("Content-Type", "text/event-stream")
+	rw.Header().Set("Cache-Control", "no-cache")
+	rw.Header().Set("Connection", "keep-alive")
+	rw.Header().Set("X-Accel-Buffering", "no") // Disable nginx buffering
+	rw.WriteHeader(200)
+
+	flusher, ok := rw.(http.Flusher)
+	if !ok {
+		writeSSE(rw, nil, "error", "streaming not supported")
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), 120*time.Second)
+	defer cancel()
+
+	resp, err := w.agent.HandleMessageStream(ctx, req.UserID, msg, func(event, data string) {
+		writeSSE(rw, flusher, event, data)
+	})
+	if err != nil {
+		w.logger.Error("agent HandleMessageStream failed", "error", err, "user_id", req.UserID)
+		writeSSE(rw, flusher, "error", "Failed to process message. Please try again.")
+		return
+	}
+	// Send final done event with complete response
+	writeSSE(rw, flusher, "done", resp)
+}
+
+// writeSSE writes a single SSE event.
+func writeSSE(w http.ResponseWriter, flusher http.Flusher, event, data string) {
+	fmt.Fprintf(w, "event: %s\ndata: %s\n\n", event, sseEscape(data))
+	if flusher != nil {
+		flusher.Flush()
+	}
+}
+
+// sseEscape escapes newlines in SSE data (each line needs a "data: " prefix).
+func sseEscape(s string) string {
+	// SSE spec: multi-line data uses multiple "data:" lines
+	// But we use JSON encoding to avoid this complexity
+	b, _ := json.Marshal(s)
+	return string(b)
+}
+
 // HandleKlines proxies kline data from Binance.
 func (w *WebHandler) HandleKlines(rw http.ResponseWriter, r *http.Request) {
 	symbol := r.URL.Query().Get("symbol")

api/agent_routes.go

@@ -11,6 +11,7 @@ import (
 func (s *Server) RegisterAgentHandler(h *agent.WebHandler) {
 	// Chat requires auth — can trigger trades and access account data
 	s.router.POST("/api/agent/chat", s.authMiddleware(), gin.WrapF(h.HandleChat))
+	s.router.POST("/api/agent/chat/stream", s.authMiddleware(), gin.WrapF(h.HandleChatStream))
 	// Public endpoints — read-only market data
 	s.router.GET("/api/agent/health", gin.WrapF(h.HandleHealth))
 	s.router.GET("/api/agent/klines", gin.WrapF(h.HandleKlines))

api/server.go

@@ -640,7 +640,38 @@ func (s *Server) authMiddleware() gin.HandlerFunc {
 }
 
 // Start Start server
+// cleanupOldData removes old decision records and equity snapshots on startup
+// to prevent unbounded database growth.
+func (s *Server) cleanupOldData() {
+	if s.store == nil {
+		return
+	}
+
+	// Clean decision records older than 90 days
+	if decisionStore := s.store.Decision(); decisionStore != nil {
+		deleted, err := decisionStore.CleanOldRecords("", 90)
+		if err != nil {
+			logger.Warnf("⚠️ Failed to clean old decision records: %v", err)
+		} else if deleted > 0 {
+			logger.Infof("🧹 Cleaned %d old decision records (>90 days)", deleted)
+		}
+	}
+
+	// Clean equity snapshots older than 180 days
+	if equityStore := s.store.Equity(); equityStore != nil {
+		deleted, err := equityStore.CleanOldRecords("", 180)
+		if err != nil {
+			logger.Warnf("⚠️ Failed to clean old equity snapshots: %v", err)
+		} else if deleted > 0 {
+			logger.Infof("🧹 Cleaned %d old equity snapshots (>180 days)", deleted)
+		}
+	}
+}
+
 func (s *Server) Start() error {
+	// Clean up old data on startup
+	s.cleanupOldData()
+
 	addr := fmt.Sprintf(":%d", s.port)
 	logger.Infof("🌐 API server starting at http://localhost%s", addr)
 	logger.Infof("📊 API Documentation:")

logger/logger.go

@@ -87,6 +87,8 @@ func Init(cfg *Config) error {
 	// Setup log file output (write to both stdout and file)
 	logDir := "data"
 	if err := os.MkdirAll(logDir, 0755); err == nil {
+		// Clean up logs older than 30 days on startup
+		cleanOldLogs(logDir, 30)
 		logFileName := filepath.Join(logDir, fmt.Sprintf("nofx_%s.log", time.Now().Format("2006-01-02")))
 		f, err := os.OpenFile(logFileName, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
 		if err == nil {
@@ -111,6 +113,38 @@ func InitWithSimpleConfig(level string) error {
 	return Init(&Config{Level: level})
 }
 
+// cleanOldLogs removes log files older than maxAge days from the log directory.
+// Called automatically during Init to prevent unbounded disk usage.
+func cleanOldLogs(logDir string, maxAgeDays int) {
+	cutoff := time.Now().AddDate(0, 0, -maxAgeDays)
+	entries, err := os.ReadDir(logDir)
+	if err != nil {
+		return
+	}
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+		name := entry.Name()
+		// Match nofx_YYYY-MM-DD.log pattern
+		if !strings.HasPrefix(name, "nofx_") || !strings.HasSuffix(name, ".log") {
+			continue
+		}
+		dateStr := strings.TrimPrefix(name, "nofx_")
+		dateStr = strings.TrimSuffix(dateStr, ".log")
+		t, err := time.Parse("2006-01-02", dateStr)
+		if err != nil {
+			continue
+		}
+		if t.Before(cutoff) {
+			path := filepath.Join(logDir, name)
+			if removeErr := os.Remove(path); removeErr == nil {
+				fmt.Printf("[logger] cleaned old log: %s\n", name)
+			}
+		}
+	}
+}
+
 // Shutdown gracefully shuts down the logger
 func Shutdown() {
 	if logFile != nil {

store/decision.go

@@ -247,12 +247,16 @@ func (s *DecisionStore) GetRecordsByDate(traderID string, date time.Time) ([]*De
 	return records, nil
 }
 
-// CleanOldRecords cleans old records from N days ago
+// CleanOldRecords cleans old records from N days ago.
+// If traderID is empty, cleans records for ALL traders.
 func (s *DecisionStore) CleanOldRecords(traderID string, days int) (int64, error) {
 	cutoffTime := time.Now().AddDate(0, 0, -days)
 
-	result := s.db.Where("trader_id = ? AND timestamp < ?", traderID, cutoffTime).
-		Delete(&DecisionRecordDB{})
+	query := s.db.Where("timestamp < ?", cutoffTime)
+	if traderID != "" {
+		query = query.Where("trader_id = ?", traderID)
+	}
+	result := query.Delete(&DecisionRecordDB{})
 	if result.Error != nil {
 		return 0, fmt.Errorf("failed to clean old records: %w", result.Error)
 	}

store/equity.go

@@ -117,12 +117,16 @@ func (s *EquityStore) GetAllTradersLatest() (map[string]*EquitySnapshot, error)
 	return result, nil
 }
 
-// CleanOldRecords cleans old records from N days ago
+// CleanOldRecords cleans old records from N days ago.
+// If traderID is empty, cleans records for ALL traders.
 func (s *EquityStore) CleanOldRecords(traderID string, days int) (int64, error) {
 	cutoffTime := time.Now().AddDate(0, 0, -days)
 
-	result := s.db.Where("trader_id = ? AND timestamp < ?", traderID, cutoffTime).
-		Delete(&EquitySnapshot{})
+	query := s.db.Where("timestamp < ?", cutoffTime)
+	if traderID != "" {
+		query = query.Where("trader_id = ?", traderID)
+	}
+	result := query.Delete(&EquitySnapshot{})
 	if result.Error != nil {
 		return 0, fmt.Errorf("failed to clean old records: %w", result.Error)
 	}

trader/aster/trader.go

@@ -2,7 +2,6 @@ package aster
 
 import (
 	"nofx/safe"
-	"context"
 	"crypto/ecdsa"
 	"encoding/hex"
 	"encoding/json"
@@ -25,7 +24,6 @@ import (
 
 // AsterTrader Aster trading platform implementation
 type AsterTrader struct {
-	ctx        context.Context
 	user       string            // Main wallet address (ERC20)
 	signer     string            // API wallet address
 	privateKey *ecdsa.PrivateKey // API wallet private key
@@ -69,7 +67,6 @@ func NewAsterTrader(user, signer, privateKeyHex string) (*AsterTrader, error) {
 	}
 
 	return &AsterTrader{
-		ctx:             context.Background(),
 		user:            user,
 		signer:          signer,
 		privateKey:      privKey,

trader/aster/trader_test.go

@@ -1,7 +1,6 @@
 package aster
 
 import (
-	"context"
 	"encoding/json"
 	"io"
 	"net/http"
@@ -194,7 +193,6 @@ func NewAsterTraderTestSuite(t *testing.T) *AsterTraderTestSuite {
 
 	// Create mock trader using mock server's URL
 	traderInstance := &AsterTrader{
-		ctx:             context.Background(),
 		user:            "0x1234567890123456789012345678901234567890",
 		signer:          "0xabcdefabcdefabcdefabcdefabcdefabcdefabcd",
 		privateKey:      privateKey,

trader/bitget/trader.go

@@ -193,6 +193,15 @@ func (t *BitgetTrader) doRequest(method, path string, body interface{}) ([]byte,
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		errBody, _ := safe.ReadAllLimited(resp.Body)
+		snippet := string(errBody)
+		if len(snippet) > 256 {
+			snippet = snippet[:256] + "..."
+		}
+		return nil, fmt.Errorf("Bitget API HTTP error (status %d): %s", resp.StatusCode, snippet)
+	}
+
 	respBody, err := safe.ReadAllLimited(resp.Body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read response: %w", err)

trader/bybit/order_sync.go

@@ -77,6 +77,15 @@ func (t *BybitTrader) getTradesViaHTTP(startTime time.Time, limit int) ([]BybitT
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		errBody, _ := safe.ReadAllLimited(resp.Body)
+		snippet := string(errBody)
+		if len(snippet) > 256 {
+			snippet = snippet[:256] + "..."
+		}
+		return nil, fmt.Errorf("Bybit API HTTP error (status %d): %s", resp.StatusCode, snippet)
+	}
+
 	body, err := safe.ReadAllLimited(resp.Body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read response: %w", err)

trader/bybit/trader_account.go

@@ -133,6 +133,15 @@ func (t *BybitTrader) getClosedPnLViaHTTP(startTime time.Time, limit int) ([]typ
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		errBody, _ := safe.ReadAllLimited(resp.Body)
+		snippet := string(errBody)
+		if len(snippet) > 256 {
+			snippet = snippet[:256] + "..."
+		}
+		return nil, fmt.Errorf("Bybit API HTTP error (status %d): %s", resp.StatusCode, snippet)
+	}
+
 	body, err := safe.ReadAllLimited(resp.Body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read response: %w", err)

trader/indodax/trader.go

@@ -176,6 +176,13 @@ func (t *IndodaxTrader) doPrivateRequest(params url.Values) ([]byte, error) {
 	if resp.StatusCode == http.StatusTooManyRequests {
 		return nil, fmt.Errorf("rate limit exceeded, please try again later")
 	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		snippet := string(data)
+		if len(snippet) > 256 {
+			snippet = snippet[:256] + "..."
+		}
+		return nil, fmt.Errorf("Indodax API HTTP error (status %d): %s", resp.StatusCode, snippet)
+	}
 
 	// Parse response to check success
 	var apiResp IndodaxResponse

trader/kucoin/trader.go

@@ -232,6 +232,15 @@ func (t *KuCoinTrader) doRequest(method, path string, body interface{}) ([]byte,
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		errBody, _ := safe.ReadAllLimited(resp.Body)
+		snippet := string(errBody)
+		if len(snippet) > 256 {
+			snippet = snippet[:256] + "..."
+		}
+		return nil, fmt.Errorf("KuCoin API HTTP error (status %d): %s", resp.StatusCode, snippet)
+	}
+
 	respBody, err := safe.ReadAllLimited(resp.Body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read response: %w", err)

trader/lighter/trader.go

@@ -2,7 +2,6 @@ package lighter
 
 import (
 	"nofx/safe"
-	"context"
 	"encoding/json"
 	"fmt"
 	"math"
@@ -59,7 +58,6 @@ type AccountResponse struct {
 
 // LighterTraderV2 New implementation using official lighter-go SDK
 type LighterTraderV2 struct {
-	ctx        context.Context
 	walletAddr string // Ethereum wallet address
 
 	client  *http.Client
@@ -127,7 +125,6 @@ func NewLighterTraderV2(walletAddr, apiKeyPrivateKeyHex string, apiKeyIndex int,
 	httpClient := lighterHTTP.NewClient(baseURL)
 
 	trader := &LighterTraderV2{
-		ctx:        context.Background(),
 		walletAddr: walletAddr,
 		client: &http.Client{
 			Timeout: 30 * time.Second,

trader/lighter/trading.go

@@ -546,6 +546,15 @@ func (t *LighterTraderV2) fetchMarketList() ([]MarketInfo, error) {
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		errBody, _ := safe.ReadAllLimited(resp.Body)
+		snippet := string(errBody)
+		if len(snippet) > 256 {
+			snippet = snippet[:256] + "..."
+		}
+		return nil, fmt.Errorf("Lighter API HTTP error (status %d): %s", resp.StatusCode, snippet)
+	}
+
 	body, err := safe.ReadAllLimited(resp.Body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read response: %w", err)

trader/okx/trader.go

@@ -228,6 +228,15 @@ func (t *OKXTrader) doRequest(method, path string, body interface{}) ([]byte, er
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		errBody, _ := safe.ReadAllLimited(resp.Body)
+		snippet := string(errBody)
+		if len(snippet) > 256 {
+			snippet = snippet[:256] + "..."
+		}
+		return nil, fmt.Errorf("OKX API HTTP error (status %d): %s", resp.StatusCode, snippet)
+	}
+
 	respBody, err := safe.ReadAllLimited(resp.Body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read response: %w", err)

web/src/pages/AgentChatPage.tsx

@@ -104,7 +104,7 @@ export function AgentChatPage() {
       const controller = new AbortController()
       abortRef.current = controller
 
-      const res = await fetch('/api/agent/chat', {
+      const res = await fetch('/api/agent/chat/stream', {
         method: 'POST',
         headers: {
           'Content-Type': 'application/json',
@@ -117,38 +117,91 @@ export function AgentChatPage() {
         const errData = await res.json().catch(() => ({}))
         throw new Error(errData.error || `Server error (${res.status})`)
       }
-      const data = await res.json()
-      const responseText = data.response || data.error || 'No response'
 
-      // Simulate streaming by revealing text in chunks (batched to reduce renders)
-      const words = responseText.split(/(\s+)/)
-      const chunkSize = Math.max(3, Math.ceil(words.length / 40)) // ~40 frames max
-      let displayed = ''
-      for (let i = 0; i < words.length; i += chunkSize) {
-        const chunk = words.slice(i, i + chunkSize).join('')
-        displayed += chunk
-        const current = displayed
-        setMessages((prev) =>
-          prev.map((m) =>
-            m.id === botId
-              ? {
-                  ...m,
-                  text: current,
-                  time: new Date().toLocaleTimeString([], {
-                    hour: '2-digit',
-                    minute: '2-digit',
-                  }),
-                }
-              : m
-          )
-        )
-        if (i + chunkSize < words.length) {
-          await new Promise((r) => setTimeout(r, 20))
+      // Real SSE streaming
+      const reader = res.body?.getReader()
+      const decoder = new TextDecoder()
+      if (!reader) throw new Error('No response body')
+
+      let buffer = ''
+      let finalText = ''
+      const now = () =>
+        new Date().toLocaleTimeString([], {
+          hour: '2-digit',
+          minute: '2-digit',
+        })
+
+      while (true) {
+        const { done, value } = await reader.read()
+        if (done) break
+
+        buffer += decoder.decode(value, { stream: true })
+        const lines = buffer.split('\n')
+        buffer = lines.pop() || '' // Keep incomplete line in buffer
+
+        let eventType = ''
+        for (const line of lines) {
+          if (line.startsWith('event: ')) {
+            eventType = line.slice(7).trim()
+          } else if (line.startsWith('data: ') && eventType) {
+            const rawData = line.slice(6)
+            try {
+              const data = JSON.parse(rawData)
+              if (eventType === 'delta') {
+                // data is the accumulated text so far
+                finalText = data
+                setMessages((prev) =>
+                  prev.map((m) =>
+                    m.id === botId
+                      ? { ...m, text: data, time: now() }
+                      : m
+                  )
+                )
+              } else if (eventType === 'tool') {
+                // Show tool being called as a status indicator
+                setMessages((prev) =>
+                  prev.map((m) =>
+                    m.id === botId
+                      ? {
+                          ...m,
+                          text: m.text || `🔧 _Calling ${data}..._`,
+                          time: now(),
+                        }
+                      : m
+                  )
+                )
+              } else if (eventType === 'done') {
+                finalText = data
+                setMessages((prev) =>
+                  prev.map((m) =>
+                    m.id === botId
+                      ? { ...m, text: data, time: now(), streaming: false }
+                      : m
+                  )
+                )
+              } else if (eventType === 'error') {
+                throw new Error(data)
+              }
+            } catch (parseErr) {
+              // Ignore malformed SSE data lines
+            }
+            eventType = ''
+          }
         }
       }
-      // Mark streaming done
+
+      // If stream ended without a "done" event, mark as done
       setMessages((prev) =>
-        prev.map((m) => (m.id === botId ? { ...m, streaming: false } : m))
+        prev.map((m) =>
+          m.id === botId && m.streaming
+            ? {
+                ...m,
+                text: finalText || m.text || 'No response',
+                streaming: false,
+                time: now(),
+              }
+            : m
+        )
       )
     } catch (e: any) {
       if (e.name === 'AbortError') {