Simply offering the latest model is no longer a competitive advantage. True value is created in the system built around the model—the system prompts, tools, and overall scaffolding. This 'harness' is what optimizes a model's performance for specific tasks and delivers a superior user experience.

The specific AI model used is becoming as irrelevant as the specific variety of corn in a gourmet dish. The true value and differentiation lie not in the commodity model itself, but in the entire system—the agentic harnesses, workflows, and user experience—that prepares and presents the final product.

An AI coding agent's performance is driven more by its "harness"—the system for prompting, tool access, and context management—than the underlying foundation model. This orchestration layer is where products create their unique value and where the most critical engineering work lies.

Performance comes from a "harness" surrounding the AI model, which includes curated data, tools, and rich context. This harness, which can be open and multi-model, is where the hard work lies—prepping the context layer so that a model's plan can execute efficiently.

The focus in AI has shifted from crafting the perfect prompt (prompt engineering) to providing the right information (context engineering), and now to building the entire operational environment—tooling, systems, and access—that enables a model to perform complex tasks. This new paradigm is called harness engineering.

As base model capabilities converge, the key differentiator is shifting to the "agent harness"—the infrastructure, tools, and skills built around the model. For vertical AI, this is where domain expertise is injected, creating specialized agents with custom tools that outperform generalist models.

The competitive edge in AI tools is moving beyond access to powerful LLMs. The real value now lies in creating a specialized "harness" or framework—an "Ironman suit" for the model—that enables it to perform narrow, high-value tasks with precision and industry-specific nuance.

Top-tier language models are becoming commoditized in their excellence. The real differentiator in agent performance is now the 'harness'—the specific context, tools, and skills you provide. A minimalist, well-crafted harness on a good model will outperform a bloated setup on a great one.

With top models reaching comparable performance, differentiation is moving to the "harness"—the user interface, tool integrations, and agentic workflows. OpenAI's ChatGPT Work, an extension of its Codecs interface to general knowledge work, shows that the system surrounding the model is now as crucial as the model itself for user adoption and value.