# Changelog v21: Agent Flows, Payments & Observability

> Version 21 introduces robust agent flow execution, integrated payments, full observability, and a refactored blog with enhanced SEO.

**URL:** https://caywork.com/learn/changelog/changelog-v21-agent-flows-payments-observability
**Published:** 2026-05-04

## Content

This release is the culmination of about a month of focused development. This version focuses on flow execution logic and backend improvements, and includes robust changes to our database schema. Here is the breakdown of the changes:

### Major Features & Improvements
- **Observability:** Integrated observability, added user action instrumentation, UTM tracking, and annonimized data handling.
- **Payments:** Integrated payment gateway, added billing plans, checkout flow, invoices, and payment processing APIs.
- **Blog & Content:** Refactored blog components and pagination, added initial post support, enhanced SEO metadata, added structured data, and added dynamic ToC to blog pages.
- **Agent Flow:**
  - Added new nodes: `UserChatOutputNode`, `UserChatInputNode`, `TextSummarizerNode`, `TextGeneratorNode`, and `ToolCallingNode`.
  - Refactored agent prompts, schema, and node connections.
  - Enhanced flow sidebar with drag-and-drop capabilities and improved UI feedback.
  - Improved agent chat styling (markdown highlight, responsive mobile chat, copyable responses).
  - **Backend Improvements:** Implemented robust step handling, improved flow execution logic, added v2 flow handling, and fixed tool calling format errors.
- **UI/UX Enhancements:**
  - Redesigned agent creation and user profile interfaces.
  - Streamlined checkout form with regional support.
  - Added Security and Privacy documentation.

### Technical & Refactoring
- **Database & Architecture:** Internal schema updates and code refactoring for improved stability and type safety.
- **Performance:** Implemented optimized caching for static assets and user avatars.
- **Improvements:** Various enhancements to UI components, layout alignment, and mobile responsiveness.
- **Fixes:** Resolved issues in analytics tracking, payment checkout, and backend connectivity.