LangGraph state machine with parallel researchers and synthesizers — every step streamed as SSE. MCP server over stdio for Claude Desktop and Claude Code. FastAPI + React on GCP.
**LangGraph** state machine with live reasoning visibility: a `plan` node routes simple queries through 2–3 parallel specialist researchers and complex queries through up to 10, then fans them through 4 parallel domain synthesizers and a fact-check node before producing a structured report. Every graph step streams to