Prompt routers and flow engineering: building modular, self-correcting agent systems

The evolution from prompt chaining to designing entire reasoning flows has transformed AI application development, shifting from linear, hand-crafted processes to more dynamic and reliable architectures. In 2024, developers initially relied on prompt chaining, which required extensive manual effort to anticipate every potential branch, but the introduction of agentic loops revolutionized this approach. These loops enable AI models to independently reason, select tools, execute actions, and adapt based on observations, thereby enhancing reliability and reducing human intervention. This shift is bolstered by powerful models with larger context windows and improved reasoning capabilities, along with advanced prompt engineering techniques that include dynamic context injection and sophisticated tool calling. Companies like Vercel have demonstrated the success of simpler architectures by reducing complexity and focusing on providing models with the right context and tools, leading to improved execution speed and accuracy. Embracing minimal agentic loops allows for more dependable AI systems by enabling models to think for themselves, marking a significant step towards reducing the need for intricate scaffolding and empowering AI to solve problems autonomously.