AI Voice agents you can actually put in production

from signalwire import AgentBase
from signalwire.core.function_result import FunctionResult

def lookup_order(order_id):  # swap for your real backend
    return {"id": order_id, "status": "shipped, arriving Tuesday"}

class SupportAgent(AgentBase):
    def __init__(self):
        super().__init__(name="support-agent")
        self.prompt_add_section("Role", body="You help callers with order issues.")

        # A context is a state machine. Each step whitelists the tools that
        # exist while it's active — the agent can't escalate before it looks up.
        steps = self.define_contexts().add_context("default")
        steps.add_step("triage") \
            .set_text("Greet the caller and ask for their 8-digit order number.") \
            .set_functions(["check_order"])
        steps.add_step("resolve") \
            .set_text("Their order is ${global_data.order_status}. Share it, "
                      "and offer a specialist if they're unhappy.") \
            .set_functions(["escalate_to_human"])

    # Type hints + docstring generate the schema — no JSON to hand-write.
    # The model decides WHEN to call it; your code decides WHAT it does.
    @AgentBase.tool(name="check_order")
    def check_order(self, order_id: str):
        """Look up an order by ID. Call before quoting any status."""
        order = lookup_order(order_id)
        # One result that SPEAKS, saves state for the next step, and advances
        # the state machine from your code — not the model's discretion.
        return FunctionResult(f"Order {order['id']} is {order['status']}.") \
            .update_global_data({"order_status": order["status"]}) \
            .swml_change_step("resolve")

    @AgentBase.tool(name="escalate_to_human")
    def escalate_to_human(self):
        """Hand the call to a live specialist."""
        # connect() is native call control: a real transfer, no extra infra.
        return FunctionResult("Connecting you now.", post_process=True) \
            .connect("+15551234567", final=True)