How is context engineering different from prompt engineering?#
Prompt engineering is about the instruction. Context engineering is about everything else the model sees: retrieved documents, project conventions, prior decisions, tool definitions, summarised history, and the material deliberately withheld to stop it crowding out what matters. A context window is a budget, and spending it well is the discipline.
What is the most valuable context to capture?#
Company knowledge that lives only in people's heads. Public knowledge is already in the model. What it cannot know is why this service is structured the way it is, which constraints are real, and which past decision is still binding — and that is exactly the material that makes an agent's output fit the organisation it is working in.
Mechanisms differ by shape: retrieval-augmented generation for documents, AGENTS.md for conventions an agent should always read, grounding for tying answers to verifiable sources.