Use strings.Builder instead of += concatenation in loops

pkg/agent/context.go

@@ -146,15 +146,15 @@ func (cb *ContextBuilder) LoadBootstrapFiles() string {
 		"IDENTITY.md",
 	}
 
-	var result string
+	var sb strings.Builder
 	for _, filename := range bootstrapFiles {
 		filePath := filepath.Join(cb.workspace, filename)
 		if data, err := os.ReadFile(filePath); err == nil {
-			result += fmt.Sprintf("## %s\n\n%s\n\n", filename, string(data))
+			fmt.Fprintf(&sb, "## %s\n\n%s\n\n", filename, data)
 		}
 	}
 
-	return result
+	return sb.String()
 }
 
 func (cb *ContextBuilder) BuildMessages(history []providers.Message, summary string, currentMessage string, media []string, channel, chatID string) []providers.Message {

pkg/agent/loop.go

@@ -818,49 +818,49 @@ func formatMessagesForLog(messages []providers.Message) string {
 		return "[]"
 	}
 
-	var result string
-	result += "[\n"
+	var sb strings.Builder
+	sb.WriteString("[\n")
 	for i, msg := range messages {
-		result += fmt.Sprintf("  [%d] Role: %s\n", i, msg.Role)
+		fmt.Fprintf(&sb, "  [%d] Role: %s\n", i, msg.Role)
 		if len(msg.ToolCalls) > 0 {
-			result += "  ToolCalls:\n"
+			sb.WriteString("  ToolCalls:\n")
 			for _, tc := range msg.ToolCalls {
-				result += fmt.Sprintf("    - ID: %s, Type: %s, Name: %s\n", tc.ID, tc.Type, tc.Name)
+				fmt.Fprintf(&sb, "    - ID: %s, Type: %s, Name: %s\n", tc.ID, tc.Type, tc.Name)
 				if tc.Function != nil {
-					result += fmt.Sprintf("      Arguments: %s\n", utils.Truncate(tc.Function.Arguments, 200))
+					fmt.Fprintf(&sb, "      Arguments: %s\n", utils.Truncate(tc.Function.Arguments, 200))
 				}
 			}
 		}
 		if msg.Content != "" {
 			content := utils.Truncate(msg.Content, 200)
-			result += fmt.Sprintf("  Content: %s\n", content)
+			fmt.Fprintf(&sb, "  Content: %s\n", content)
 		}
 		if msg.ToolCallID != "" {
-			result += fmt.Sprintf("  ToolCallID: %s\n", msg.ToolCallID)
+			fmt.Fprintf(&sb, "  ToolCallID: %s\n", msg.ToolCallID)
 		}
-		result += "\n"
+		sb.WriteString("\n")
 	}
-	result += "]"
-	return result
+	sb.WriteString("]")
+	return sb.String()
 }
 
 // formatToolsForLog formats tool definitions for logging
-func formatToolsForLog(tools []providers.ToolDefinition) string {
-	if len(tools) == 0 {
+func formatToolsForLog(toolDefs []providers.ToolDefinition) string {
+	if len(toolDefs) == 0 {
 		return "[]"
 	}
 
-	var result string
-	result += "[\n"
-	for i, tool := range tools {
-		result += fmt.Sprintf("  [%d] Type: %s, Name: %s\n", i, tool.Type, tool.Function.Name)
-		result += fmt.Sprintf("      Description: %s\n", tool.Function.Description)
+	var sb strings.Builder
+	sb.WriteString("[\n")
+	for i, tool := range toolDefs {
+		fmt.Fprintf(&sb, "  [%d] Type: %s, Name: %s\n", i, tool.Type, tool.Function.Name)
+		fmt.Fprintf(&sb, "      Description: %s\n", tool.Function.Description)
 		if len(tool.Function.Parameters) > 0 {
-			result += fmt.Sprintf("      Parameters: %s\n", utils.Truncate(fmt.Sprintf("%v", tool.Function.Parameters), 200))
+			fmt.Fprintf(&sb, "      Parameters: %s\n", utils.Truncate(fmt.Sprintf("%v", tool.Function.Parameters), 200))
 		}
 	}
-	result += "]"
-	return result
+	sb.WriteString("]")
+	return sb.String()
 }
 
 // summarizeSession summarizes the conversation history for a session.
@@ -936,14 +936,18 @@ func (al *AgentLoop) summarizeSession(agent *AgentInstance, sessionKey string) {
 
 // summarizeBatch summarizes a batch of messages.
 func (al *AgentLoop) summarizeBatch(ctx context.Context, agent *AgentInstance, batch []providers.Message, existingSummary string) (string, error) {
-	prompt := "Provide a concise summary of this conversation segment, preserving core context and key points.\n"
+	var sb strings.Builder
+	sb.WriteString("Provide a concise summary of this conversation segment, preserving core context and key points.\n")
 	if existingSummary != "" {
-		prompt += "Existing context: " + existingSummary + "\n"
+		sb.WriteString("Existing context: ")
+		sb.WriteString(existingSummary)
+		sb.WriteString("\n")
 	}
-	prompt += "\nCONVERSATION:\n"
+	sb.WriteString("\nCONVERSATION:\n")
 	for _, m := range batch {
-		prompt += fmt.Sprintf("%s: %s\n", m.Role, m.Content)
+		fmt.Fprintf(&sb, "%s: %s\n", m.Role, m.Content)
 	}
+	prompt := sb.String()
 
 	response, err := agent.Provider.Chat(ctx, []providers.Message{{Role: "user", Content: prompt}}, nil, agent.Model, map[string]interface{}{
 		"max_tokens":  1024,

pkg/agent/memory.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 	"time"
 )
 
@@ -100,7 +101,8 @@ func (ms *MemoryStore) AppendToday(content string) error {
 // GetRecentDailyNotes returns daily notes from the last N days.
 // Contents are joined with "---" separator.
 func (ms *MemoryStore) GetRecentDailyNotes(days int) string {
-	var notes []string
+	var sb strings.Builder
+	first := true
 
 	for i := 0; i < days; i++ {
 		date := time.Now().AddDate(0, 0, -i)
@@ -109,53 +111,42 @@ func (ms *MemoryStore) GetRecentDailyNotes(days int) string {
 		filePath := filepath.Join(ms.memoryDir, monthDir, dateStr+".md")
 
 		if data, err := os.ReadFile(filePath); err == nil {
-			notes = append(notes, string(data))
+			if !first {
+				sb.WriteString("\n\n---\n\n")
+			}
+			sb.Write(data)
+			first = false
 		}
 	}
 
-	if len(notes) == 0 {
-		return ""
-	}
-
-	// Join with separator
-	var result string
-	for i, note := range notes {
-		if i > 0 {
-			result += "\n\n---\n\n"
-		}
-		result += note
-	}
-	return result
+	return sb.String()
 }
 
 // GetMemoryContext returns formatted memory context for the agent prompt.
 // Includes long-term memory and recent daily notes.
 func (ms *MemoryStore) GetMemoryContext() string {
-	var parts []string
-
-	// Long-term memory
 	longTerm := ms.ReadLongTerm()
-	if longTerm != "" {
-		parts = append(parts, "## Long-term Memory\n\n"+longTerm)
-	}
-
-	// Recent daily notes (last 3 days)
 	recentNotes := ms.GetRecentDailyNotes(3)
-	if recentNotes != "" {
-		parts = append(parts, "## Recent Daily Notes\n\n"+recentNotes)
-	}
 
-	if len(parts) == 0 {
+	if longTerm == "" && recentNotes == "" {
 		return ""
 	}
 
-	// Join parts with separator
-	var result string
-	for i, part := range parts {
-		if i > 0 {
-			result += "\n\n---\n\n"
+	var sb strings.Builder
+	sb.WriteString("# Memory\n\n")
+
+	if longTerm != "" {
+		sb.WriteString("## Long-term Memory\n\n")
+		sb.WriteString(longTerm)
+	}
+
+	if recentNotes != "" {
+		if longTerm != "" {
+			sb.WriteString("\n\n---\n\n")
 		}
-		result += part
+		sb.WriteString("## Recent Daily Notes\n\n")
+		sb.WriteString(recentNotes)
 	}
-	return fmt.Sprintf("# Memory\n\n%s", result)
+
+	return sb.String()
 }