# Context Engineering

> The practice of selecting, ordering, compressing, and updating the information a model sees.

- Category: Context & Memory
- Stage: Rising
- Also called: Context design, Context assembly
- Canonical: https://www.joelcsaji.com/ai-dictionary/context-engineering

## Plain English

Prompt engineering asks the model well. Context engineering gives it the right room to think in.

## Example

A coding tool includes the active file, related tests, recent errors, project rules, and only the relevant docs.

## Why it matters

For agents, context quality often matters more than clever wording.

## Related

- [Context Window](https://www.joelcsaji.com/ai-dictionary/context-window)
- [Retrieval-Augmented Generation](https://www.joelcsaji.com/ai-dictionary/retrieval-augmented-generation)
- [Compaction](https://www.joelcsaji.com/ai-dictionary/compaction)

## Sources

- [Anthropic: Effective Harnesses](https://www.anthropic.com/engineering/effective-harnesses-for-long-running-agents)
- [Google Cloud Generative AI Glossary](https://docs.cloud.google.com/docs/generative-ai/glossary)