Primary Sources for Claude Code Engineering Practice

Citation policy

Claude Ships Code uses primary sources for product facts. That means official Anthropic Claude Code documentation, official Anthropic GitHub repositories, and official Model Context Protocol documentation. Secondary commentary can inspire questions, but it should not anchor factual claims.

Where the site makes a recommendation, it separates the source-backed fact from the engineering judgment. For example, the docs establish that hooks can run at lifecycle events; this site recommends using Stop hooks for narrow deterministic gates.

Claim map

The overview and how-it-works docs support claims about Claude Code surfaces, the agentic loop, tools, local project access, sessions, checkpoints, and execution environments.

The best-practices and extension overview docs support workflow recommendations around verification, exploration, context management, hooks, MCP, skills, subagents, and plugins.

The hooks, MCP, skills, subagents, GitHub Actions, SDK, CLI, settings, security, and changelog pages support their respective specialist articles.

Model facts are cited separately because they move fastest. Current model IDs, prices, context limits, and default effort come from the Anthropic models overview; the claim that Fable 5.1 defaults to High effort in Claude Code and Medium on Claude.ai and Cowork comes from the Fable 5.1 announcement; Fast mode pricing and the mid-conversation tool-change beta come from the Opus 5 announcement; breaking changes for forced tool use and thinking blocks come from the Fable 5.1 platform overview.

Primary-source anchor: Anthropic's extension overview is the source used here to compare Claude Code extension mechanisms rather than treating them as interchangeable.

Freshness model

Claude Code changes quickly, so source freshness matters. The current pass was made on September 19, 2026, and refreshed the model and effort defaults across the site: Fable 5.1 at High effort in Claude Code, Opus 5 as the general starting point with Fast mode through usage credits, and Opus 4.8 demoted to legacy. The changelog page is designed to be updated weekly as a freshness surface.

When a page discusses latest version behavior, verify the official changelog and the installed `claude --version` before changing team policy. This site deliberately does not pin a CLI version number, because the only version that governs your behavior is the one installed on your machine or runner.

Network boundaries

This bibliography intentionally stays inside Claude Code engineering practice. It links to sibling sites for neighboring territories: Claude Weekly for news, Claude Has Skills for skill examples, Claude Memories for memory depth, Claude Context for context engineering, and Claude Builds for project examples.

This prevents duplicate articles across the network and keeps each page useful for its assigned query territory.