The Python layer wraps the standalone COBOL banking system with three capabilities:
- Bridge + Integrity (Layer 2) — Subprocess execution, DAT file I/O, SQLite sync, SHA-256 hash chains
- REST API (Layer 3) — FastAPI endpoints exposing all banking, codegen, and chain operations
- LLM Tool-Use (Layer 3) — AI chatbot with RBAC-gated tool execution (Ollama local / Anthropic cloud)
| Package | Files | Purpose |
|---|---|---|
python/ |
bridge.py, integrity.py, settlement.py, cross_verify.py, simulator.py, cli.py, auth.py |
Core bridge, integrity, settlement, RBAC |
python/api/ |
app.py, models.py, dependencies.py, routes_*.py |
FastAPI REST layer |
python/llm/ |
tools.py, tool_executor.py, providers.py, conversation.py, audit.py |
LLM tool-use architecture |
python/cobol_codegen/ |
ast_nodes.py, parser.py, generator.py, templates.py, editor.py, validator.py |
AST-based COBOL code generation |
python/tests/ |
28 test files | 800 automated tests |
# First-time setup (compile COBOL + seed all nodes)
python -m python.cli setup
# Run full demo (compile → seed → settle → verify → tamper → detect)
python -m python.cli prove
# Process a transaction
python -m python.cli transact BANK_A ACT-A-001 D 1000 "Deposit"
# Verify all chains
python -m python.cli verify --allpip install -e ".[dev]"
uvicorn python.api.app:app --reload
# Open http://localhost:8000/docs for interactive API explorerpython -m pytest python/tests/ -v # 807 tests, all green┌─────────────────────────────────────────────┐
│ Layer 3: REST API + LLM Tool-Use │
│ FastAPI endpoints, Pydantic models, │
│ Ollama/Anthropic providers, RBAC tools │
├─────────────────────────────────────────────┤
│ Layer 2: Python Bridge + Integrity │
│ COBOLBridge (Mode A/B), IntegrityChain, │
│ SettlementCoordinator, CrossNodeVerifier │
├─────────────────────────────────────────────┤
│ Layer 1: COBOL Banking System │
│ 10 programs, 5 copybooks, DAT files │
│ SHA-256 chain per node │
└─────────────────────────────────────────────┘
See docs/ARCHITECTURE.md for the full topology, data flow, and integrity model.