Source Index

Primary Sources for Claude Context Engineering

An annotated source index for Claude context-window facts, context engineering, prompt caching, Claude Code memory, subagents, and MCP resources.

Updated 2026-07-06 7 min read Cite this page

"Count the tokens in a message before you send it to Claude."

Source: Token counting, Claude Platform Docs.

How to use this source index

Use this page to verify the factual base behind ClaudeContext.com. The source index is intentionally narrow: official Anthropic and MCP sources are preferred over commentary. Third-party writing can be useful for interpretation, but it should not override current primary docs for model limits, API behavior, or Claude Code behavior.

Which source answers which question

Use the model overview for current model comparison and context-window rows. Use the context-window docs for what counts in context and when compaction is the primary strategy. Use token counting for preflight estimates. Use prompt caching for repeated stable prefixes. Use Claude Code memory and subagent docs for Code-specific behavior. Use the MCP resources spec for resource semantics.

Citation policy

Every article page includes a stable "Cite this page" block and a source list. When a fact is current and likely to drift, the page should include an updated date and point to the exact source used. If a page cannot verify a claim from a primary source, it should present the claim as interpretation or omit it.

FAQ

Why not cite more blog posts?

The site is designed for durable factual answers. Official docs are more appropriate for changing Claude API, Claude Code, and MCP behavior.

Can this source list change?

Yes. The freshness page should record new source checks and any factual changes.

Sources Used

  • Effective context engineering for AI agents, Anthropic Engineering. Accessed 2026-07-06. Primary explanation of context engineering, context pollution, compaction, note-taking, and sub-agent architectures.
  • Context windows, Claude Platform Docs. Accessed 2026-07-06. Official context-window behavior, token accumulation, extended thinking and tool-use accounting, and compaction guidance.
  • Models overview, Claude Platform Docs. Accessed 2026-07-06. Current model comparison, including context-window and output limits listed by Anthropic.
  • Prompting best practices, Claude Platform Docs. Accessed 2026-07-06. Official guidance on clear instructions, examples, XML sections, long-context prompting, and tool-use prompting.
  • Token counting, Claude Platform Docs. Accessed 2026-07-06. Official endpoint guidance for estimating input tokens, costs, rate limits, and model routing.
  • Prompt caching, Claude Platform Docs. Accessed 2026-07-06. Official prompt-caching behavior, cache lifetime, prefix caching, usage fields, and invalidation patterns.
  • Context engineering: memory, compaction, and tool clearing, Claude Cookbook. Accessed 2026-07-06. Cookbook comparison of server-side compaction, context editing, tool-result clearing, and memory.
  • How Claude remembers your project, Claude Code Docs. Accessed 2026-07-06. Official explanation of fresh Claude Code sessions, CLAUDE.md, auto memory, and load behavior.
  • Claude Code settings, Claude Code Docs. Accessed 2026-07-06. Configuration categories, including memory files, settings, skills, MCP servers, and precedence.
  • Create custom subagents, Claude Code Docs. Accessed 2026-07-06. Official subagent context-window behavior, scoped prompts, tool access, and context preservation.
  • Resources, Model Context Protocol Specification. Accessed 2026-07-06. Protocol definition for resources, resource templates, subscriptions, contents, and annotations.
  • MCP connector, Claude Platform Docs. Accessed 2026-07-06. Official Claude API MCP connector behavior for remote MCP servers, OAuth, multiple servers, and tool access.

Cite this page

Suggested citation: Claude Context, "Primary Sources for Claude Context Engineering," updated 2026-07-06, https://claudecontext-com.pages.dev/sources/.

This page is an independent educational resource and is not affiliated with Anthropic.