agent: keep thread metadata out of session history

pkg/agent/loop.go

@@ -1476,15 +1476,6 @@ func (al *AgentLoop) runAgentLoop(
 	agent *AgentInstance,
 	opts processOptions,
 ) (string, error) {
-	opts.UserMessage = formatUserMessageWithThreadMetadata(
-		opts.UserMessage,
-		opts.SenderDisplayName,
-		opts.SenderUsername,
-		opts.SenderID,
-		opts.MessageID,
-		opts.ReplyToMessageID,
-	)
-
 	// Record last channel for heartbeat notifications (skip internal channels and cli)
 	if opts.Channel != "" && opts.ChatID != "" && !constants.IsInternalChannel(opts.Channel) {
 		channelKey := fmt.Sprintf("%s:%s", opts.Channel, opts.ChatID)
@@ -1638,6 +1629,14 @@ func (al *AgentLoop) runTurn(ctx context.Context, ts *turnState) (turnResult, er
 		summary = ts.agent.Sessions.GetSummary(ts.sessionKey)
 	}
 	ts.captureRestorePoint(history, summary)
+	annotatedUserMessage := formatUserMessageWithThreadMetadata(
+		ts.userMessage,
+		ts.opts.SenderDisplayName,
+		ts.opts.SenderUsername,
+		ts.opts.SenderID,
+		ts.opts.MessageID,
+		ts.opts.ReplyToMessageID,
+	)
 
 	messages := ts.agent.ContextBuilder.BuildMessages(
 		history,
@@ -1650,6 +1649,7 @@ func (al *AgentLoop) runTurn(ctx context.Context, ts *turnState) (turnResult, er
 		ts.opts.SenderDisplayName,
 		activeSkillNames(ts.agent, ts.opts)...,
 	)
+	annotateCurrentUserMessageForLLM(messages, ts.userMessage, annotatedUserMessage)
 
 	cfg := al.GetConfig()
 	maxMediaSize := cfg.Agents.Defaults.GetMaxMediaSize()
@@ -1680,6 +1680,7 @@ func (al *AgentLoop) runTurn(ctx context.Context, ts *turnState) (turnResult, er
 				ts.opts.SenderID, ts.opts.SenderDisplayName,
 				activeSkillNames(ts.agent, ts.opts)...,
 			)
+			annotateCurrentUserMessageForLLM(messages, ts.userMessage, annotatedUserMessage)
 			messages = resolveMediaRefs(messages, al.mediaStore, maxMediaSize)
 		}
 	}
@@ -2052,6 +2053,7 @@ turnLoop:
 					nil, ts.channel, ts.chatID, ts.opts.SenderID, ts.opts.SenderDisplayName,
 					activeSkillNames(ts.agent, ts.opts)...,
 				)
+				annotateCurrentUserMessageForLLM(messages, ts.userMessage, annotatedUserMessage)
 				callMessages = messages
 				if gracefulTerminal {
 					callMessages = append(append([]providers.Message(nil), messages...), ts.interruptHintMessage())
@@ -3555,6 +3557,26 @@ func inboundMetadata(msg bus.InboundMessage, key string) string {
 	return msg.Metadata[key]
 }
 
+func annotateCurrentUserMessageForLLM(
+	messages []providers.Message,
+	rawUserMessage string,
+	annotatedUserMessage string,
+) {
+	if rawUserMessage == annotatedUserMessage {
+		return
+	}
+	for i := len(messages) - 1; i >= 0; i-- {
+		if messages[i].Role != "user" {
+			continue
+		}
+		if messages[i].Content != rawUserMessage {
+			continue
+		}
+		messages[i].Content = annotatedUserMessage
+		return
+	}
+}
+
 func formatUserMessageWithThreadMetadata(
 	content string,
 	senderDisplayName string,
@@ -3574,11 +3596,15 @@ func formatUserMessageWithThreadMetadata(
 	if from != "" {
 		metaParts = append(metaParts, fmt.Sprintf("from:%s", from))
 	}
+	msgMetaParts := make([]string, 0, 2)
 	if messageID != "" {
-		metaParts = append(metaParts, fmt.Sprintf("msg:#%s", messageID))
+		msgMetaParts = append(msgMetaParts, fmt.Sprintf("#%s", messageID))
 	}
 	if replyToMessageID != "" {
-		metaParts = append(metaParts, fmt.Sprintf("reply_to:#%s", replyToMessageID))
+		msgMetaParts = append(msgMetaParts, fmt.Sprintf("reply_to:#%s", replyToMessageID))
+	}
+	if len(msgMetaParts) > 0 {
+		metaParts = append(metaParts, fmt.Sprintf("msgs:%s", strings.Join(msgMetaParts, ", ")))
 	}
 
 	annotation := fmt.Sprintf("[%s]", strings.Join(metaParts, "; "))

pkg/agent/loop_test.go

@@ -178,7 +178,7 @@ func TestFormatUserMessageWithThreadMetadata(t *testing.T) {
 
 	t.Run("includes from, message and reply IDs", func(t *testing.T) {
 		got := formatUserMessageWithThreadMetadata("ping", "Alice", "@alice", "discord:1", "123", "120")
-		want := "[from:Alice (@alice); msg:#123; reply_to:#120]\nping"
+		want := "[from:Alice (@alice); msgs:#123, reply_to:#120]\nping"
 		if got != want {
 			t.Fatalf("formatUserMessageWithThreadMetadata() = %q, want %q", got, want)
 		}
@@ -186,14 +186,14 @@ func TestFormatUserMessageWithThreadMetadata(t *testing.T) {
 
 	t.Run("empty content returns annotation only", func(t *testing.T) {
 		got := formatUserMessageWithThreadMetadata("", "", "", "discord:1", "123", "")
-		want := "[from:discord:1; msg:#123]"
+		want := "[from:discord:1; msgs:#123]"
 		if got != want {
 			t.Fatalf("formatUserMessageWithThreadMetadata() = %q, want %q", got, want)
 		}
 	})
 }
 
-func TestProcessMessage_AnnotatesThreadMetadataInPromptAndHistory(t *testing.T) {
+func TestProcessMessage_AnnotatesThreadMetadataInPromptOnly(t *testing.T) {
 	tmpDir, err := os.MkdirTemp("", "agent-test-*")
 	if err != nil {
 		t.Fatalf("Failed to create temp dir: %v", err)
@@ -245,7 +245,7 @@ func TestProcessMessage_AnnotatesThreadMetadataInPromptAndHistory(t *testing.T)
 		t.Fatal("provider did not receive any messages")
 	}
 
-	wantAnnotated := "[from:Alice (@alice); msg:#123; reply_to:#120]\nhello"
+	wantAnnotated := "[from:Alice (@alice); msgs:#123, reply_to:#120]\nhello"
 	lastMessage := provider.lastMessages[len(provider.lastMessages)-1]
 	if lastMessage.Role != "user" || lastMessage.Content != wantAnnotated {
 		t.Fatalf("last provider message = %+v, want user annotation %q", lastMessage, wantAnnotated)
@@ -263,8 +263,8 @@ func TestProcessMessage_AnnotatesThreadMetadataInPromptAndHistory(t *testing.T)
 	if len(history) != 2 {
 		t.Fatalf("expected history len=2, got %d", len(history))
 	}
-	if history[0].Role != "user" || history[0].Content != wantAnnotated {
+	if history[0].Role != "user" || history[0].Content != "hello" {
-		t.Fatalf("history user message = %+v, want %q", history[0], wantAnnotated)
+		t.Fatalf("history user message = %+v, want %q", history[0], "hello")
 	}
 }