代码上下文组装工具

 Your Project (500 files, 2M tokens)
│
├── auth/login.ts        ←  The bug is HERE
├── auth/session.ts      ←  login imports this
├── api/http.ts          ←  session imports this
├── utils/config.ts      ← ️ timeout settings live here
│
├── pages/home.tsx       ←  completely irrelevant
├── pages/about.tsx      ←  completely irrelevant
├── components/Button.tsx ←  completely irrelevant
└── ... 493 more files    ←  all irrelevant

You: "Fix the login timeout bug"
                │
                ▼
┌──────────────────────────────────────────────────────┐
│  ️ Arachne: "I'll find exactly what you need"      │
│                                                      │
│  L1  Project tree (so AI knows the structure)      │
│  L2  login.ts (the file you're working on)         │
│  L3  http.ts, session.ts (found via search +       │
│        dependency chain: login → session → http)     │
│  L4 ️ config.ts (frequently accessed, has timeout)  │
│                                                      │
│  → 30,000 tokens of perfectly curated context        │
└──────────────────────────────────────────────────────┘
                │
                ▼
        AI generates accurate fix 

┌─────────────────────────────────────────────┐
│              Token Budget (e.g. 30K)        │
├────────────┬────────────────────────────────┤
│ L1: Fixed  │ File tree overview (10%)       │
│ (always)   │ Project structure snapshot     │
├────────────┼────────────────────────────────┤
│ L2: Short  │ Current file + recent (20%)   │
│ (context)  │ What you're working on now     │
├────────────┼────────────────────────────────┤
│ L3: Assoc  │ Search + dependencies (50%)  │
│ (relevant) │ BM25 + semantic + dep chain   │
├────────────┼────────────────────────────────┤
│ L4: Spare  │ Frequently accessed (20%)     │
│ (backup)   │ Files you use most            │
└────────────┴────────────────────────────────┘

Output order: L1 → L3 → L4 → L2  (mitigates "Lost in the Middle")

BM25 Score (keyword) ──┐
                       ├── Weighted Merge (α=0.5) → Best Results
Cosine Similarity ─────┘
(nomic-embed-text 768D)

// 500+ token class → automatically split into methods
public class UserService {       // ← detected as container
    public User findById() {}    // ← sub-chunk 1
    public List<User> findAll()  // ← sub-chunk 2
    public User save() {}        // ← sub-chunk 3
    // ... fields, constructor   // ← remainder chunk
}

// Small class (<500 tokens) → kept as single chunk (no overhead)
public class TinyDTO { ... }     // ← single chunk, efficient

Without sub-chunking:
  AI asks: "Fix the findById bug"
  → BM25 hits UserService class
  → Entire class sent: 6,000 tokens  

With sub-chunking:
  AI asks: "Fix the findById bug"
  → BM25 hits findById() method only
  → Just the method sent: 80 tokens    75x savings!

Phase 1 (Indexing/Search):    15/15 
Phase 2 (Assembly/Deps):      26/26 
Phase 2 (KV-Cache Bridge):   33/33 
Phase 3 (Semantic/Hybrid):    10/10 
Stability (Reddit-proof):     44/44 
─────────────────────────────────────
Total:                       128/128 

npm install n2-arachne

{
  "mcpServers": {
    "n2-arachne": {
      "command": "node",
      "args": ["/path/to/n2-arachne/dist/index.js"],
      "env": {
        "ARACHNE_PROJECT_DIR": "/path/to/your/project"
      }
    }
  }
}

module.exports = {
    projectDir: '/path/to/your/project',
    dataDir: './data',

    indexing: {
        autoIndex: true,
        maxFileSize: 512 * 1024,    // 512KB max per file
    },

    // Enable semantic search (requires Ollama)
    embedding: {
        enabled: true,              // default: false
        provider: 'ollama',
        model: 'nomic-embed-text',
        endpoint: 'http://localhost:11434',
    },

    assembly: {
        defaultBudget: 30000,       // tokens
    },
};

{
  "action": "assemble",
  "query": "HTTP request timeout error handling",
  "activeFile": "lib/executor.js",
  "budget": 20000
}

{
  "mcpServers": {
    "n2-soul": {
      "command": "node",
      "args": ["/path/to/n2-soul/index.js"]
    },
    "n2-arachne": {
      "command": "node",
      "args": ["/path/to/n2-arachne/dist/index.js"],
      "env": {
        "ARACHNE_PROJECT_DIR": "/path/to/your/project"
      }
    }
  }
}

{
  "mcpServers": {
    "n2-soul": {
      "command": "node",
      "args": ["/path/to/n2-soul/index.js"]
    },
    "n2-arachne": {
      "command": "node",
      "args": ["/path/to/n2-arachne/dist/index.js"],
      "env": {
        "ARACHNE_PROJECT_DIR": "/path/to/your/project"
      }
    },
    "n2-qln": {
      "command": "node",
      "args": ["/path/to/n2-qln/index.js"]
    }
  }
}

User: "Fix the login timeout bug"
     │
     ▼
┌─── QLN (Router) ──────────────────────────────────────┐
│ 1000+ tools → Semantic routing finds:                 │
│   → n2_arachne.assemble (context)                     │
│   → n2_arachne.search (code search)                   │
│ Token cost: 2 tool defs instead of 1000+              │
└────────────────┬──────────────────────────────────────┘
                 │
                 ▼
┌─── Arachne (Context) ─────────────────────────────────┐
│ L1: Project tree overview                              │
│ L2: auth/login.ts (current file)                       │
│ L3: BM25 + semantic search → timeout-related code      │
│     + dependency chain: login.ts → api.ts → http.ts    │
│ L4: Frequently accessed config files                   │
│ → 30K tokens of perfectly curated context              │
└────────────────┬──────────────────────────────────────┘
                 │
                 ▼
┌─── Soul (Memory) ─────────────────────────────────────┐
│ "Last session, Rose fixed a similar timeout in         │
│  api.ts line 47. Decision: increased to 30s."          │
│ → Past context + decisions + handoff notes             │
│ → KV-Cache: instant session restoration                │
└────────────────┬──────────────────────────────────────┘
                 │
                 ▼
┌─── Ark (Security) ────────────────────────────────────┐
│  No hardcoded credentials in generated code          │
│  Timeout value from config, not magic number         │
│  Error handling follows project conventions           │
│ → Code verification before commit                      │
└───────────────────────────────────────────────────────┘