Claude Code's six-layer architecture uses a 3-layer context compressor at 92% threshold and Redis-based multi-agent FSM protocol. The model is just one node in a harness. Anthropic's Claude Code operates across six distinct layers, not as a simple CLI. The architecture, detailed by developer @akshay_pachaar, reveals a harness system where the model is just one node in a perception-action-observation loop. Key facts Six layers: Input, Knowledge, Execution, Integration, Multi-Agent, Observability. Knowledge layer uses 3-layer context compressor at 92% threshold. Multi-Agent layer uses Redis pub/sub for subagent communication. Execution layer uses typed registry with one handler per tool. Master loop: perception → action → observation. Key Takeaways Claude Code's six-layer architecture uses a 3-layer context compressor at 92% threshold and Redis-based multi-agent FSM protocol. The model is just one node in a harness.…