Headline AI Agent products such as Codex, Claude Desktop, and Cursor 3.0 have recently converged to a three-column layout design almost simultaneously. This trend is not a coincidence or mutual imitation, but a natural outcome of the optimal solution in Agent interaction models.
The reason is not complicated. The two-column design of traditional chatbots is sufficient to handle Q&A needs, but AI in the Agent era can now independently write code, modify files, and call tools. Users need an intuitive way to review the results of these operations, which has led to the emergence of the right-side workspace. More importantly, users are spending more time on Agents, and the scenario of frequently switching to professional software like VSCode is decreasing. Direct secondary editing within the Agent has become a common expectation. In Codex's major version update in April, the most significant change was the right-side workspace, which has evolved from a simple viewing area into a multi-functional interactive zone.
In this update, Codex has announced the slogan "Codex for (almost) everything," indicating ambitions beyond code generation. It aims to cover multi-domain professional workflows and establish a complete closed loop from generation to manual fine-tuning. However, there are still limitations in directly editing file formats such as PPTX after generation, which may be a temporary strategic choice.
In the current Agent capability puzzle, MCP has already effectively solved the issue of tool connectivity, and Agent Skills address the problem of knowledge reserves for "how to do it." However, users' secondary editing needs remain a clear gap—no matter how powerful the AI is, the final 5% of precise adjustments often require human intervention. Relying solely on Markdown editors is not a long-term solution.
The most feasible breakthrough path points toward a plugin ecosystem. The Agent focuses on the core scheduling layer, opening up file preview, secondary editing, and vertical professional capabilities to community plugins for expansion. Users can install them as needed, achieving personalized workflows. Compared to Skills that are easy to replicate, plugins can draw on the mature charging and copyright protection mechanisms of the App Store, providing continuous incentives for developers. Codex has already launched an early plugin marketplace, and Cursor also shows a similar direction.
