┌─────────────────────────────────────────────────────────────────────────────┐
│  1. Data Source Layer                                                       │
│  ┌──────────────┐    REST     ┌─────────────────┐                          │
│  │ PostgreSQL   │ ──────────► │                 │                          │
│  │ MySQL        │             │ WarpConnector    │  auto-discovery           │
│  └──────────────┘             │ (query pushdown) │  pagination, schema       │
│       Warp REST API           └────────┬────────┘                          │
└────────────────────────────────────────┼──────────────────────────────────┘
                                          │
┌─────────────────────────────────────────▼──────────────────────────────────┐
│  2. DuckDB Core Layer                                                       │
│  ┌──────────────────────────────────────────────────────────────────────┐  │
│  │ OLAPEngine                                                            │  │
│  │  • DuckDB (in-memory, columnar)   • QueryCache (LRU + TTL)            │  │
│  │  • SchemaCatalog (multi-source)   • MaterializedViewManager           │  │
│  │  • FetchStrategy (lazy load)      • SQLGuardrails (SELECT only)       │  │
│  └──────────────────────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────┬──────────────────────────────────┘
                                          │
┌─────────────────────────────────────────▼──────────────────────────────────┐
│  3. LLM Tool Layer                                                          │
│  ┌─────────────┐  ┌──────────────────┐  ┌─────────────────┐                 │
│  │ ToolExecutor│  │ 10 tools         │  │ MCP / REST / SDK│                 │
│  │ (dispatch)  │─►│ query_data, etc. │─►│ → LLM → Result  │                 │
│  └─────────────┘  └──────────────────┘  └─────────────────┘                 │
└─────────────────────────────────────────────────────────────────────────────┘

pip install -e .

pip install -e ".[mcp]"     # MCP Server support
pip install -e ".[rest]"    # REST API (FastAPI + uvicorn)
pip install -e ".[dev]"     # Development (pytest, ruff, mypy)
pip install -e ".[all]"     # Everything

from fusion import OLAPEngine

engine = OLAPEngine(memory_limit="4GB")
engine.connect_source("mydb", {
    "type": "warp",
    "base_url": "http://localhost:8000",
    "database": "mydb",
})

executor = engine.get_tool_executor()

# Discover available data
sources = executor.list_sources()

# Run an analytical query (auto-loads referenced tables)
result = executor.query_data("SELECT * FROM mydb.orders LIMIT 10")

# Aggregate data
agg = executor.aggregate_data(
    table="mydb.orders",
    group_by="status",
    agg_column="amount",
    agg_func="SUM",
)

# Create a materialized view
executor.create_view(
    name="daily_revenue",
    sql="SELECT status, SUM(amount) as total FROM mydb.orders GROUP BY status",
    refresh="hourly",
)

fusion-mcp --warp-url http://localhost:8000 --database mydb

{
  "mcpServers": {
    "fusion": {
      "command": "fusion-mcp",
      "args": ["--warp-url", "http://localhost:8000", "--database", "mydb"]
    }
  }
}

fusion-mcp --warp-url http://localhost:8000 --auto-discover

fusion-rest --warp-url http://localhost:8000 --auto-discover --port 9000

from fusion import get_openai_tools, OLAPEngine

engine = OLAPEngine()
engine.connect_source("mydb", {"type": "warp", "base_url": "http://localhost:8000"})
executor = engine.get_tool_executor()

# Get tool definitions for OpenAI Chat Completions API
tools = get_openai_tools()

# When the LLM makes a tool call:
result = executor.execute("query_data", {"sql": "SELECT ..."})

git clone https://github.com/yasinyaman/warp.git
cd warp
docker compose up -d

fusion/
├── __init__.py              # Public API exports
├── engine.py                # OLAPEngine — main orchestration
├── cache.py                 # QueryCache (LRU + TTL)
├── catalog.py               # SchemaCatalog — multi-source metadata
├── guardrails.py            # SQLGuardrails — blocks destructive SQL
├── result.py                # QueryResult — format conversions
├── strategy.py              # FetchStrategy — smart table loading
├── exceptions.py            # Custom exception hierarchy
├── connectors/
│   ├── base.py              # BaseConnector (abstract)
│   └── warp.py              # WarpConnector (Warp REST API)
├── tools/
│   ├── definitions.py       # 10 tool schemas (OpenAI + MCP)
│   ├── executor.py          # ToolExecutor — routes tool calls
│   ├── mcp_server.py        # MCP Server (stdio transport)
│   └── rest_server.py       # REST API Server (FastAPI)
└── views/
    └── materialized.py      # MaterializedViewManager

pip install -e ".[all]"
pytest tests/ -v           # 236 tests
ruff check fusion/         # Lint
python -m demo.demo        # Demo with synthetic data