So many people hating on how many lines of code this is and how it's "slop" But Claude Code still has the best memory, context recall and speed that all agent builders should learn from. 1. Loads memory from 6 priority layers, bottom to top: Org policy → user prefs → project rules → local overrides → auto-extracted memories → team-synced shared memory. Rules can be conditional: they only activate when you're touching matching files. Auto-recall uses a side-query to rank and pick the top 5 most relevant memories from 200+ candidates. The whole thing is memoized per session. It's closer to a filesystem than a prompt. 2. Compresses Context with 3 tiers: Tier 1: Replay a pre-extracted session summary ((min 10K tokens, max 40K). No API call. Fastest. Tier 2: Surgically prune old tool results from the cached prefix without rebuilding the cache. Cache-safe. Tier 3: Full conversation summarization via Sonnet. Last resort. Has a retry loop that progressively truncates the head if the compaction request itself is too long 3. Parallelization everywhere Startup fires keychain reads, git ops, and subprocess work all concurrently: I/O finishes during module import, effectively free (65ms). Nothing blocks first render. File search returns results in ~5ms before the index finishes building. Fork agents share byte-identical request prefixes for max prompt cache reuse. Tools declare themselves as concurrency-safe and execute in parallel during streaming. If one errors, siblings abort but the parent query continues. A function literally named DANGEROUS_uncachedSystemPromptSection() exists to scare devs away from breaking the cache. Nothing is allowed to be slow.