# Context Engineering

> Free resources, with credit to the original creators.

## Resources
- [AGENTS.md](/context-engineering/agent-instruction-files/agentsmd-agents-md/index.md): Open format for a repo instruction file that coding agents read. (beginner; other; closed resource; by AGENTS.md (multi-vendor open format))
- [Equipping agents for the real world with Agent Skills](/context-engineering/agent-instruction-files/anthropic-agent-skills/index.md): Packaging instructions and scripts as loadable skills. (intermediate; West; closed resource; by Anthropic)
- [Effective context engineering for AI agents](/context-engineering/context-management/anthropic-effective-context-engineering/index.md): Treats context as a finite budget: compaction, notes, sub-agents. (intermediate; West; closed resource; by Anthropic)
- [Letta documentation](/context-engineering/memory/letta-memory-docs/index.md): Explore documentation for agents that keep state across interactions. (intermediate; West; closed resource; by Letta)
- [Context Engineering for Agents](/context-engineering/context-management/rlancemartin-context-engineering-for-agents/index.md): Write/select/compress/isolate taxonomy of context strategies. (intermediate; West; closed resource; by Lance Martin)
- [Effective harnesses for long-running agents](/context-engineering/loop-engineering/anthropic-effective-harnesses-long-running-agents/index.md): Harness design for agents that work across many context windows. (advanced; West; closed resource; by Anthropic)
- [Context Rot: How Increasing Input Tokens Impacts LLM Performance](/context-engineering/context-management/chroma-context-rot/index.md): Measures how output quality drops as input length grows. (advanced; West; closed resource; by Chroma)
- [Context Engineering for AI Agents: Lessons from Building Manus](/context-engineering/context-management/manus-context-engineering-lessons/index.md): KV-cache-aware design, file system as memory, keep errors in context. (advanced; other; closed resource; by Manus)
- [A Survey of Context Engineering for LLMs (arXiv 2507.13334)](/context-engineering/context-management/mei-et-al-a-survey-of-context-engineering-for-llms/index.md): A research map of retrieval, context processing and memory systems. (advanced; CN; closed resource; by Mei et al. (Chinese Academy of Sciences et al.))
- [RAG Techniques](/context-engineering/retrieval-and-rag/nirdiamant-rag-techniques/index.md): Compare retrieval designs through code-oriented examples. (advanced; other; closed resource; by Nir Diamant and contributors)