fix: context propagation in LLM calls, SSE error handling, security hardening

- Propagate request context through MCP client (Request.Ctx field)
  — Client disconnects now cancel in-flight LLM API calls (both streaming and non-streaming)
  — Prevents wasted LLM tokens when user navigates away mid-response
- proxyBinance: use http.NewRequestWithContext for context-aware upstream calls
  — Client disconnects cancel Binance proxy requests
  — Distinguishes client cancellation from upstream failures
- Fix SSE parse bug in AgentChatPage: catch block was swallowing error events
  — throw new Error(data) for 'error' events was caught by the same try/catch
  — Now parse JSON separately, then handle events outside try/catch
- Add io.LimitReader to Hyperliquid coins.go JSON decoder (4MB limit)
- Use safe.ReadAllLimited in batch ticker handler for consistency
- Sanitize URL validation error in handler_ai_model.go (was leaking raw error)
- Cache agent tool definitions (built once, reused per message)
- Sort trade history by exit time for consistent ordering

agent/agent.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"log/slog"
 	"net/http"
+	"sort"
 	"strconv"
 	"strings"
 	"time"
@@ -18,6 +19,7 @@ import (
 	"nofx/manager"
 	"nofx/market"
 	"nofx/mcp"
+	"nofx/safe"
 	"nofx/store"
 )
 
@@ -95,6 +97,16 @@ func (a *Agent) Start() {
 	if a.config.EnableBriefs { a.brain.StartMarketBriefs(a.config.BriefTimes) }
 	a.scheduler = NewScheduler(a, a.logger)
 	a.scheduler.Start(context.Background())
+
+	// Periodic cleanup of stale chat sessions (older than 4 hours)
+	safe.GoNamed("chat-history-cleanup", func() {
+		ticker := time.NewTicker(30 * time.Minute)
+		defer ticker.Stop()
+		for range ticker.C {
+			a.history.CleanOld(4 * time.Hour)
+		}
+	})
+
 	a.logger.Info("NOFXi agent is online 🚀")
 }
 
@@ -234,6 +246,7 @@ func (a *Agent) thinkAndAct(ctx context.Context, userID int64, lang, text string
 			Messages:   messages,
 			Tools:      tools,
 			ToolChoice: "auto",
+			Ctx:        ctx,
 		}
 
 		resp, err := a.aiClient.CallWithRequestFull(req)
@@ -241,7 +254,7 @@ func (a *Agent) thinkAndAct(ctx context.Context, userID int64, lang, text string
 			a.logger.Error("LLM call failed", "error", err, "round", round)
 			if round == 0 {
 				// First round failed — try without tools as fallback
-				plainReq := &mcp.Request{Messages: messages}
+				plainReq := &mcp.Request{Messages: messages, Ctx: ctx}
 				plainResp, plainErr := a.aiClient.CallWithRequest(plainReq)
 				if plainErr != nil {
 					return a.noAIFallback(lang, text)
@@ -293,7 +306,7 @@ func (a *Agent) thinkAndAct(ctx context.Context, userID int64, lang, text string
 	}
 
 	// If we exhausted all rounds, ask LLM for a final text response without tools
-	finalReq := &mcp.Request{Messages: messages}
+	finalReq := &mcp.Request{Messages: messages, Ctx: ctx}
 	finalResp, err := a.aiClient.CallWithRequest(finalReq)
 	if err != nil {
 		return a.noAIFallback(lang, text)
@@ -343,13 +356,13 @@ func (a *Agent) thinkAndActStream(ctx context.Context, userID int64, lang, text
 	toolsUsed := false
 
 	for round := 0; round < maxToolRounds; round++ {
-		req := &mcp.Request{Messages: messages, Tools: tools, ToolChoice: "auto"}
+		req := &mcp.Request{Messages: messages, Tools: tools, ToolChoice: "auto", Ctx: ctx}
 		resp, err := a.aiClient.CallWithRequestFull(req)
 		if err != nil {
 			a.logger.Error("LLM call failed (stream)", "error", err, "round", round)
 			if round == 0 {
 				// First round failed — try streaming without tools as fallback
-				streamReq := &mcp.Request{Messages: messages}
+				streamReq := &mcp.Request{Messages: messages, Ctx: ctx}
 				streamText, streamErr := a.aiClient.CallWithRequestStream(streamReq, func(chunk string) {
 					onEvent(StreamEventDelta, chunk)
 				})
@@ -396,7 +409,7 @@ func (a *Agent) thinkAndActStream(ctx context.Context, userID int64, lang, text
 
 		// After tool execution, stream the next LLM response for real-time UX.
 		// Omit tools so LLM can't start another tool round — it must produce text.
-		streamReq := &mcp.Request{Messages: messages}
+		streamReq := &mcp.Request{Messages: messages, Ctx: ctx}
 		streamText, streamErr := a.aiClient.CallWithRequestStream(streamReq, func(chunk string) {
 			onEvent(StreamEventDelta, chunk)
 		})
@@ -409,7 +422,7 @@ func (a *Agent) thinkAndActStream(ctx context.Context, userID int64, lang, text
 	}
 
 	// Exhausted all tool rounds — stream the final synthesis response
-	finalReq := &mcp.Request{Messages: messages}
+	finalReq := &mcp.Request{Messages: messages, Ctx: ctx}
 	finalText, err := a.aiClient.CallWithRequestStream(finalReq, func(chunk string) {
 		onEvent(StreamEventDelta, chunk)
 	})
@@ -582,9 +595,16 @@ func (a *Agent) gatherContext(text string) string {
 			}
 		}
 	}
+	// Collect and sort matched symbols for deterministic selection
+	sortedSymbols := make([]string, 0, len(matched))
+	for sym := range matched {
+		sortedSymbols = append(sortedSymbols, sym)
+	}
+	sort.Strings(sortedSymbols)
+
 	// Cap at 5 symbols to avoid slow context gathering
 	count := 0
-	for sym := range matched {
+	for _, sym := range sortedSymbols {
 		if count >= 5 { break }
 		md, err := market.Get(sym + "USDT")
 		if err == nil && md.CurrentPrice > 0 {

agent/tools.go

@@ -4,14 +4,20 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"sort"
 	"strings"
 	"time"
 
 	"nofx/mcp"
 )
 
-// agentTools defines the tools available to the LLM for autonomous action.
-func agentTools() []mcp.Tool {
+// cachedTools holds the static tool definitions (built once, reused per message).
+var cachedTools = buildAgentTools()
+
+// agentTools returns the tools available to the LLM for autonomous action.
+func agentTools() []mcp.Tool { return cachedTools }
+
+func buildAgentTools() []mcp.Tool {
 	return []mcp.Tool{
 		{
 			Type: "function",
@@ -423,6 +429,13 @@ func (a *Agent) toolGetTradeHistory(argsJSON string) string {
 		return `{"trades": [], "message": "no closed trades found"}`
 	}
 
+	// Sort trades by exit time (most recent first) for consistent ordering across traders
+	sort.Slice(trades, func(i, j int) bool {
+		ti, _ := trades[i]["exit_time"].(string)
+		tj, _ := trades[j]["exit_time"].(string)
+		return ti > tj // reverse chronological
+	})
+
 	// Only return up to the limit
 	if len(trades) > args.Limit {
 		trades = trades[:args.Limit]

agent/web.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"log/slog"
 	"net/http"
+	"nofx/safe"
 	"regexp"
 	"time"
 )
@@ -171,7 +172,7 @@ func (w *WebHandler) HandleKlines(rw http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	proxyBinance(rw, fmt.Sprintf("https://fapi.binance.com/fapi/v1/klines?symbol=%s&interval=%s&limit=300", symbol, interval))
+	proxyBinance(rw, r.Context(), fmt.Sprintf("https://fapi.binance.com/fapi/v1/klines?symbol=%s&interval=%s&limit=300", symbol, interval))
 }
 
 // HandleTicker proxies ticker data from Binance.
@@ -184,22 +185,22 @@ func (w *WebHandler) HandleTicker(rw http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	proxyBinance(rw, fmt.Sprintf("https://fapi.binance.com/fapi/v1/ticker/24hr?symbol=%s", symbol))
+	proxyBinance(rw, r.Context(), fmt.Sprintf("https://fapi.binance.com/fapi/v1/ticker/24hr?symbol=%s", symbol))
 }
 
 // HandleTickers handles GET /api/agent/tickers?symbols=BTCUSDT,ETHUSDT,SOLUSDT
-// Batch endpoint: fetches multiple tickers in one API call to Binance.
+// Batch endpoint: fetches multiple tickers concurrently, returns array.
 func (w *WebHandler) HandleTickers(rw http.ResponseWriter, r *http.Request) {
 	symbolsParam := r.URL.Query().Get("symbols")
 	if symbolsParam == "" {
 		symbolsParam = "BTCUSDT,ETHUSDT,SOLUSDT"
 	}
 
-	// Validate and build JSON array of symbols
-	symbols := []string{}
-	for _, s := range splitAndTrim(symbolsParam) {
+	// Validate symbols
+	var symbols []string
+	for _, s := range splitComma(symbolsParam) {
 		if validSymbolRe.MatchString(s) {
-			symbols = append(symbols, `"`+s+`"`)
+			symbols = append(symbols, s)
 		}
 	}
 	if len(symbols) == 0 {
@@ -211,15 +212,70 @@ func (w *WebHandler) HandleTickers(rw http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Binance supports batch ticker: /fapi/v1/ticker/24hr with multiple symbols
-	url := fmt.Sprintf("https://fapi.binance.com/fapi/v1/ticker/24hr?symbols=[%s]", joinStrings(symbols, ","))
-	proxyBinance(rw, url)
+	// Fetch all tickers concurrently with context propagation
+	ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
+	defer cancel()
+
+	type result struct {
+		idx  int
+		data json.RawMessage
+	}
+	results := make(chan result, len(symbols))
+	for i, sym := range symbols {
+		idx, s := i, sym
+		safe.GoNamed("ticker-fetch-"+s, func() {
+			req, err := http.NewRequestWithContext(ctx, "GET",
+				fmt.Sprintf("https://fapi.binance.com/fapi/v1/ticker/24hr?symbol=%s", s), nil)
+			if err != nil {
+				results <- result{idx: idx}
+				return
+			}
+			resp, err := binanceClient.Do(req)
+			if err != nil {
+				results <- result{idx: idx}
+				return
+			}
+			defer resp.Body.Close()
+			if resp.StatusCode != 200 {
+				results <- result{idx: idx}
+				return
+			}
+			body, err := safe.ReadAllLimited(resp.Body, 16*1024)
+			if err != nil {
+				results <- result{idx: idx}
+				return
+			}
+			results <- result{idx: idx, data: body}
+		})
+	}
+
+	// Collect results in order
+	ordered := make([]json.RawMessage, len(symbols))
+	for range symbols {
+		r := <-results
+		if r.data != nil {
+			ordered[r.idx] = r.data
+		}
+	}
+
+	// Filter out nil entries and write response
+	out := make([]json.RawMessage, 0, len(ordered))
+	for _, d := range ordered {
+		if d != nil {
+			out = append(out, d)
+		}
+	}
+	rw.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(rw).Encode(out)
 }
 
-// splitAndTrim splits a comma-separated string and trims whitespace.
-func splitAndTrim(s string) []string {
-	parts := []string{}
-	for _, p := range regexp.MustCompile(`\s*,\s*`).Split(s, -1) {
+// commaRe is pre-compiled for splitComma — avoids recompiling on every call.
+var commaRe = regexp.MustCompile(`\s*,\s*`)
+
+// splitComma splits a comma-separated string, trims whitespace, skips empty.
+func splitComma(s string) []string {
+	var parts []string
+	for _, p := range commaRe.Split(s, -1) {
 		if p != "" {
 			parts = append(parts, p)
 		}
@@ -227,21 +283,18 @@ func splitAndTrim(s string) []string {
 	return parts
 }
 
-// joinStrings joins strings with a separator.
-func joinStrings(ss []string, sep string) string {
-	result := ""
-	for i, s := range ss {
-		if i > 0 {
-			result += sep
-		}
-		result += s
-	}
-	return result
-}
-
-func proxyBinance(rw http.ResponseWriter, url string) {
-	resp, err := binanceClient.Get(url)
+func proxyBinance(rw http.ResponseWriter, ctx context.Context, url string) {
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
 	if err != nil {
+		writeJSON(rw, 500, map[string]string{"error": "failed to create request"})
+		return
+	}
+	resp, err := binanceClient.Do(req)
+	if err != nil {
+		// Distinguish client cancellation from upstream failures
+		if ctx.Err() != nil {
+			return // Client disconnected, no point writing response
+		}
 		writeJSON(rw, 502, map[string]string{"error": "upstream request failed"})
 		return
 	}

api/handler_ai_model.go

@@ -155,7 +155,8 @@ func (s *Server) handleUpdateModelConfigs(c *gin.Context) {
 		if modelData.CustomAPIURL != "" {
 			cleanURL := strings.TrimSuffix(modelData.CustomAPIURL, "#")
 			if err := security.ValidateURL(cleanURL); err != nil {
-				c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("Invalid custom_api_url for model %s: %s", modelID, err.Error())})
+				logger.Warnf("Invalid custom_api_url for model %s: %v", modelID, err)
+				c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("Invalid custom_api_url for model %s: URL must be a valid HTTPS endpoint", modelID)})
 				return
 			}
 		}

mcp/client.go

@@ -501,6 +501,10 @@ func (client *Client) callWithRequestFull(req *Request) (*LLMResponse, error) {
 	if err != nil {
 		return nil, fmt.Errorf("failed to create request: %w", err)
 	}
+	// Propagate request context so client disconnects cancel in-flight LLM calls
+	if req.Ctx != nil {
+		httpReq = httpReq.WithContext(req.Ctx)
+	}
 
 	resp, err := client.HTTPClient.Do(httpReq)
 	if err != nil {
@@ -539,6 +543,10 @@ func (client *Client) callWithRequest(req *Request) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("failed to create request: %w", err)
 	}
+	// Propagate request context so client disconnects cancel in-flight LLM calls
+	if req.Ctx != nil {
+		httpReq = httpReq.WithContext(req.Ctx)
+	}
 
 	resp, err := client.HTTPClient.Do(httpReq)
 	if err != nil {
@@ -684,8 +692,13 @@ func (client *Client) CallWithRequestStream(req *Request, onChunk func(string))
 
 	// Idle-timeout watchdog: cancel the request if no SSE line arrives for 60 seconds.
 	// This breaks the scanner out of an indefinitely blocking Read on a hung connection.
+	// Use request's Ctx as parent so client disconnects propagate cancellation.
 	const idleTimeout = 60 * time.Second
-	ctx, cancel := context.WithCancel(context.Background())
+	parentCtx := req.Ctx
+	if parentCtx == nil {
+		parentCtx = context.Background()
+	}
+	ctx, cancel := context.WithCancel(parentCtx)
 	defer cancel()
 	resetCh := make(chan struct{}, 1)
 	safe.GoNamed("mcp-stream-idle-watchdog", func() {

mcp/request.go

@@ -1,5 +1,7 @@
 package mcp
 
+import "context"
+
 // Message represents a conversation message.
 // Supports plain messages (Role+Content), assistant tool-call messages (ToolCalls),
 // and tool result messages (Role="tool", ToolCallID, Content).
@@ -62,6 +64,11 @@ type Request struct {
 	// Advanced features
 	Tools      []Tool `json:"tools,omitempty"`       // Available tools list
 	ToolChoice string `json:"tool_choice,omitempty"` // Tool choice strategy ("auto", "none", {"type": "function", "function": {"name": "xxx"}})
+
+	// Context for cancellation — not serialized to JSON.
+	// If set, HTTP requests use this as the parent context so client disconnects
+	// propagate and cancel in-flight LLM calls.
+	Ctx context.Context `json:"-"`
 }
 
 // NewMessage creates a message

provider/hyperliquid/coins.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"nofx/logger"
 	"sort"
@@ -82,8 +83,9 @@ func (p *CoinProvider) fetchCoins(ctx context.Context) error {
 	}
 
 	// Response is an array: [meta, [assetCtxs...]]
+	// Limit read to 4MB to prevent memory exhaustion from oversized responses
 	var rawResp []json.RawMessage
-	if err := json.NewDecoder(resp.Body).Decode(&rawResp); err != nil {
+	if err := json.NewDecoder(io.LimitReader(resp.Body, 4*1024*1024)).Decode(&rawResp); err != nil {
 		return fmt.Errorf("failed to decode response: %w", err)
 	}
 

web/src/pages/AgentChatPage.tsx

@@ -145,45 +145,48 @@ export function AgentChatPage() {
             eventType = line.slice(7).trim()
           } else if (line.startsWith('data: ') && eventType) {
             const rawData = line.slice(6)
+            let data: string
             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) {
+              data = JSON.parse(rawData)
+            } catch {
               // Ignore malformed SSE data lines
+              eventType = ''
+              continue
+            }
+            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)
             }
             eventType = ''
           }