一套 RAG 系統長怎樣

flowchart LR
  CLIENT(["🤖 Agent / 聊天前端
/ 別的系統"]):::result
  MCP["🔌 MCP 介面
只開一個 rag_search"]:::data
  subgraph BUILD["🏗️ BUILD · 建索引(做一次)"]
    direction TB
    DOC[("原始文件
手冊 · SOP")]:::infra
    OCR["OCR
掃描檔轉文字"]:::proc
    CH["切塊 + embedding"]:::proc
    DOC -->|數位文字| CH
    DOC -.掃描檔.-> OCR --> CH
  end
  VDB[("🗄️ 向量庫
片段 · 向量 · metadata")]:::data
  AUTH["access_grants
誰能看哪本"]:::data
  subgraph SERVE["🔎 SERVE · 每次提問"]
    direction TB
    CTL{"控制器
agentic 才有"}:::decision
    RET["檢索 R + 組裝 A"]:::proc
    GEN["生成 G · 標出處"]:::proc
    CTL -->|決定查什麼| RET
    RET -.不夠再查一輪.-> CTL
    RET --> GEN
  end
  ANS(["✅ 有據答案
+ 出處"]):::result
  CLIENT --> MCP --> CTL
  CH --> VDB
  AUTH -.授權過濾.-> VDB
  RET <-->|語意檢索 top-k| VDB
  GEN --> ANS
  classDef proc fill:#dbeafe,stroke:#2563eb,stroke-width:2px,color:#17335e
  classDef data fill:#fef3c7,stroke:#d97706,stroke-width:2px,color:#78350f
  classDef result fill:#dcfce7,stroke:#16a34a,stroke-width:2px,color:#14532d
  classDef infra fill:#e5e9f0,stroke:#475569,stroke-width:2px,color:#1e293b
  classDef decision fill:#ede9fe,stroke:#7c3aed,stroke-width:2px,color:#4c1d95
  style BUILD fill:#f8fafc,stroke:#cbd5e1,color:#475569
  style SERVE fill:#eff6ff,stroke:#93c5fd,color:#1e40af