Function demo_4_fallback_router

demo.py:272–309

()

# =============================================================================

def demo_4_fallback_router():
    print("\n" + "=" * 60)
    print("Demo 4: Fallback Router - Exhausted Retries")
    print("=" * 60)

    schema = ResponseSchema(must_be_json=True, required_keys=["result"])
    config = ControlLayerConfig(total_tokens=800, max_attempts=3, base_delay_ms=50)

    llm = make_deterministic_llm([
        "This is not JSON at all.",
        "Still not JSON: just plain text.",
        "Nope, still plain text on attempt 3.",
    ])
    layer = ControlLayer(
        llm_fn=llm,
        system_prompt="You are a structured output assistant.",
        schema=schema,
        config=config,
    )
    layer.register_fallback(
        "cached_response",
        lambda q: json.dumps({"result": "fallback", "source": "cache", "query": q[:50]}),
    )
    layer.register_fallback(
        "escalate",
        lambda q: json.dumps({"result": "escalated", "reason": "max retries exceeded"}),
    )

    packet = layer.run(
        user_input="What is the result of running the context engine on query X?",
        constraints=["Respond only with a JSON object containing a 'result' key."],
    )

    print(f"  Final outcome:  {'PASSED' if packet.validation.passed else 'FAILED'}")
    print(f"  Strategy used:  {packet.strategy_used.value}")
    print(f"  Attempts used:  {packet.attempts}")
    print(f"  Response:       {packet.response[:120]}")
    return packet, layer.audit


# =============================================================================