Ratel: BM25 tool catalog cuts AI agent context spend 87%
Ratel (ratel-ai/ratel, 186★, Apache-2.0 core + MIT SDKs) ships an in-process BM25 tool catalog. On BFCL v3: ~87% fewer tokens, tool selection within ±5 points.
didilili/ai-agents-from-zero: a Chinese MIT AI agent guide
MIT Chinese guide from Datawhale with 27 chapters on LangChain, LangGraph, MCP, RAG, Skills, and fine-tuning. 1.9k stars, two completed projects in May 2026. Code is Python; prose is Chinese.