# Claude Context

An independent, source-backed guide to Claude context windows, context engineering, compaction, prompt caching, Claude Code context, and MCP resources.

ClaudeContext.com is an independent educational publication. It is not affiliated with, endorsed by, or sponsored by Anthropic.

## Core Pages
- Claude Context Window: What Counts and What Breaks: https://claudecontext-com.pages.dev/context-window/ - A sourced guide to Claude context windows: what counts, why larger context is not automatically better, and how to measure tokens before you send.
- Context Engineering vs Prompt Engineering: https://claudecontext-com.pages.dev/context-engineering/ - A practical boundary between Claude prompt engineering and context engineering, grounded in Anthropic source material.
- The Claude Context Stack: https://claudecontext-com.pages.dev/context-stack/ - A layered map of the information Claude can receive: instructions, examples, tools, retrieval, memory, history, and outputs.
- Compaction, Tool Clearing, and Memory: https://claudecontext-com.pages.dev/compaction/ - How to choose between Claude compaction, tool-result clearing, and memory when long conversations or agents exceed useful context.
- Claude Code Context: CLAUDE.md, Auto Memory, and Subagents: https://claudecontext-com.pages.dev/claude-code-context/ - How Claude Code manages context through fresh windows, CLAUDE.md, auto memory, settings, MCP servers, and subagents.
- MCP Resources as Claude Context: https://claudecontext-com.pages.dev/mcp-resources/ - What MCP resources are, how they provide structured context to Claude, and when to use resources instead of tools or prompt text.
- Prompt Caching for Large Claude Context: https://claudecontext-com.pages.dev/prompt-caching/ - When Claude prompt caching helps, what it caches, what TTLs mean, and why caching is not a substitute for context selection.
- Long Context Prompt Patterns for Claude: https://claudecontext-com.pages.dev/long-context-prompts/ - How to structure long Claude prompts with source packets, XML sections, query placement, quote extraction, and token budgets.
- Context Engineering Templates: https://claudecontext-com.pages.dev/templates/ - Reusable templates for Claude context packets, source packets, compaction handoffs, MCP resource inventories, and token-budget reviews.
- Claude Context Freshness Log: https://claudecontext-com.pages.dev/freshness/ - A dated source-watch page for Claude context engineering facts, model context windows, Claude Code context behavior, and MCP resource docs.
- Primary Sources for Claude Context Engineering: https://claudecontext-com.pages.dev/sources/ - An annotated source index for Claude context-window facts, context engineering, prompt caching, Claude Code memory, subagents, and MCP resources.

## Free Tools
- Tools index: https://claudecontext-com.pages.dev/tools/ - Free client-side Claude context tools.
- Claude Context Window Planner: https://claudecontext-com.pages.dev/tools/context-planner/ - Allocate a Claude context window across instructions, tools, history, retrieval, working notes, and output reserve using current published model window sizes.
- Claude Compaction Simulator: https://claudecontext-com.pages.dev/tools/compaction-simulator/ - See how long Claude conversations can be summarized: what survives compaction, what becomes a short note, and what should be re-fetched or discarded.
- Claude Prompt Caching Savings Calculator: https://claudecontext-com.pages.dev/tools/caching-calculator/ - Estimate daily savings from Claude prompt caching using current dated cache write and cache read prices from the Claude Platform pricing docs.

## Use This Site For
- Claude context-window definitions and token budgeting.
- Context engineering versus prompt engineering distinctions.
- Compaction, tool-result clearing, memory, prompt caching, and MCP resource decision support.
- Source-backed Claude Code context notes about CLAUDE.md, auto memory, settings, and subagents.
- Browser-only tools for planning context windows, simulating compaction, and estimating prompt caching savings.

## Freshness
Primary-source claims were checked on 2026-07-06. See /freshness/ for the source watchlist.