Fork tasks from snapshots; snapshot only when text follows tool calls

internal/agents/manager.go

@@ -86,6 +86,8 @@ type live struct {
 	wantCompact bool
 	rateLimited map[string]any
 
+	toolsSinceText bool
+
 	contextModel  string
 	contextUsed   int
 	contextWindow int
@@ -608,6 +610,7 @@ func (m *Manager) message(ctx context.Context, l *live, actor, text string, imag
 	l.wantCompact = false
 	l.compacting = compacting
 	l.rateLimited = nil
+	l.toolsSinceText = false
 	m.mu.Unlock()
 
 	return l.sess.Send(text, imgs...)
@@ -643,7 +646,10 @@ func (m *Manager) ensureLive(ctx context.Context, sess api.AgentSession, task ap
 		owner:     sess.Owner,
 	}
 
-	g := taskGuidance(task)
+	g, err := m.taskGuidance(ctx, task)
+	if err != nil {
+		return nil, err
+	}
 	tools := []mcp.Tool{m.askTool(l), m.cancelQuestionTool(l), m.createTaskTool(l), m.setMergeTitleTool(l)}
 	hooks := map[string][]claude.HookMatcher{
 		"UserPromptSubmit": {{Func: remindGuidance(g)}},
@@ -675,9 +681,15 @@ func (m *Manager) ensureLive(ctx context.Context, sess api.AgentSession, task ap
 	if err != nil {
 		return nil, err
 	}
-	if started {
+	switch {
+	case started:
 		opts.Resume = sess.VendorSessionId
-	} else {
+	case sess.ForkedFrom != nil:
+		opts.SessionID = sess.VendorSessionId
+		opts.Resume = *sess.ForkedFrom
+		opts.ResumeAt = *sess.ForkedAt
+		opts.ForkSession = true
+	default:
 		opts.SessionID = sess.VendorSessionId
 	}
 
@@ -691,9 +703,6 @@ func (m *Manager) ensureLive(ctx context.Context, sess api.AgentSession, task ap
 
 	m.live[sess.Id] = l
 	go m.pump(l)
-	if l.owner == "" {
-		go m.snapshotTimer(l)
-	}
 	return l, nil
 }
 
@@ -764,11 +773,29 @@ func (m *Manager) handle(ctx context.Context, l *live, ev claude.Event) error {
 		if err != nil {
 			return err
 		}
+		uuid, err := ev.UUID()
+		if err != nil {
+			return err
+		}
 		for _, b := range blocks {
-			err = m.handleAssistantBlock(ctx, l, b, parent)
+			err = m.handleAssistantBlock(ctx, l, b, parent, uuid)
 			if err != nil {
 				return err
 			}
+			if parent != "" || l.owner != "" {
+				continue
+			}
+			switch {
+			case b.Type == "tool_use":
+				l.toolsSinceText = true
+			case b.Type == "text" && l.toolsSinceText:
+				l.toolsSinceText = false
+				seq, err := m.store.LastTaskSeq(ctx, l.taskID)
+				if err != nil {
+					return err
+				}
+				m.snapshotSoon(l, api.SnapshotTriggerMessage, seq)
+			}
 		}
 		if parent != "" {
 			return nil
@@ -792,6 +819,10 @@ func (m *Manager) handle(ctx context.Context, l *live, ev claude.Event) error {
 		if err != nil {
 			return err
 		}
+		uuid, err := ev.UUID()
+		if err != nil {
+			return err
+		}
 		for _, b := range blocks {
 			if b.Type != "tool_result" {
 				continue
@@ -804,7 +835,7 @@ func (m *Manager) handle(ctx context.Context, l *live, ev claude.Event) error {
 				"tool_use_id": b.ToolUseID,
 				"is_error":    b.IsError,
 				"content":     content,
-			}, parent))
+			}, parent, uuid))
 			if err != nil {
 				return err
 			}
@@ -838,7 +869,7 @@ func (m *Manager) handle(ctx context.Context, l *live, ev claude.Event) error {
 		if sha != "" {
 			payload["commit"] = sha
 		}
-		m.snapshotSoon(l, api.SnapshotTriggerTurnEnd)
+		m.snapshotSoon(l, api.SnapshotTriggerTurnEnd, 0)
 		switch {
 		case handoff:
 			payload["handoff"] = true
@@ -957,16 +988,16 @@ func (m *Manager) updateContext(ctx context.Context, l *live, used, window int)
 	return m.emit(ctx, l, agentActor, "session.context", map[string]any{"model": l.contextModel, "used": used, "window": window})
 }
 
-func (m *Manager) handleAssistantBlock(ctx context.Context, l *live, b claude.Block, parent string) error {
+func (m *Manager) handleAssistantBlock(ctx context.Context, l *live, b claude.Block, parent, uuid string) error {
 	switch b.Type {
 	case "text":
-		return m.emit(ctx, l, agentActor, "agent.message", withParent(map[string]any{"text": b.Text}, parent))
+		return m.emit(ctx, l, agentActor, "agent.message", withParent(map[string]any{"text": b.Text}, parent, uuid))
 
 	case "thinking":
 		if b.Thinking == "" {
 			return nil
 		}
-		return m.emit(ctx, l, agentActor, "agent.thinking", withParent(map[string]any{"text": b.Thinking}, parent))
+		return m.emit(ctx, l, agentActor, "agent.thinking", withParent(map[string]any{"text": b.Thinking}, parent, uuid))
 
 	case "tool_use":
 		input, err := decode(b.Input)
@@ -977,15 +1008,19 @@ func (m *Manager) handleAssistantBlock(ctx context.Context, l *live, b claude.Bl
 			"id":    b.ID,
 			"name":  b.Name,
 			"input": input,
-		}, parent))
+		}, parent, uuid))
 	}
 
-	return m.emit(ctx, l, agentActor, "agent.vendor", withParent(store.ToPayload(b), parent))
+	return m.emit(ctx, l, agentActor, "agent.vendor", withParent(store.ToPayload(b), parent, uuid))
 }
 
-func withParent(payload map[string]any, parent string) map[string]any {
+func withParent(payload map[string]any, parent, uuid string) map[string]any {
 	if parent != "" {
 		payload["parent_tool_use_id"] = parent
+		return payload
+	}
+	if uuid != "" {
+		payload["vendor_uuid"] = uuid
 	}
 	return payload
 }