How Claude Code Works
An independent, educational deep dive into Claude Code's internal architecture, based on analysis of a leaked source snapshot, covering its agent loop, context compression, streaming and safety design.
How Claude Code Works is an educational architecture analysis of Claude Code, written after a snapshot of its source code circulated in the community. The authors read through the code together with Claude Code itself and wrote up sixteen articles covering key design decisions from its core loop to its safety protections, aiming to give a shorter path into understanding a large production coding agent than reading the source directly.
Topics covered include why the tool feels fast despite multi-second model latency, through full-pipeline token streaming, speculative tool pre-execution and a nine-stage parallel startup sequence; how it silently recovers from errors such as context overflow or truncated output through several fallback strategies; a four-level progressive context-compression scheme that trims, deduplicates, folds and finally summarizes conversation history as it nears its limit; and a seven-layer defense-in-depth design for guarding against dangerous commands, including workspace trust and syntax-tree-based command analysis.
The authors state the analysis is independent research and inference, not an official Anthropic design document, and that Anthropic source code is not redistributed.