17 - Order Processing

from pydantic import BaseModel, Field

class ActionDetails(BaseModel):
    charge_id: str | None = None
    amount: float | None = None
    email_sent_to: str | None = None

class OrderAgentOutput(BaseModel):
    action: str = Field(description="Action taken: 'charge' or 'email'")
    action_details: ActionDetails
    action_requested: str | None = Field(
        default=None,
        description="'fraud_review' for amounts over $1000, or None"
    )
    status_message: str

from polos import Agent, tool, WorkflowContext

@tool(description="Charge a customer using Stripe")
async def charge_stripe(ctx: WorkflowContext, input: ChargeInput) -> ChargeOutput:
    # Process payment
    return ChargeOutput(charge_id="ch_123", status="succeeded", amount=input.amount)

@tool(description="Send order confirmation email")
async def send_confirmation_email(ctx: WorkflowContext, input: EmailInput) -> EmailOutput:
    return EmailOutput(sent=True, message_id="msg_123")

order_agent = Agent(
    id="order_agent",
    provider="openai",
    model="gpt-4o-mini",
    system_prompt="""You are an order processing assistant.

RULES:
1. When asked to process a payment, use charge_stripe first
2. After charging:
   - If amount > $1000: Set action_requested='fraud_review' (DO NOT send email)
   - If amount <= $1000: Immediately send confirmation email
3. After fraud approval: Send the confirmation email""",
    tools=[charge_stripe, send_confirmation_email],
    output_schema=OrderAgentOutput,
)

from polos import workflow, WorkflowContext

@workflow(id="order_processing")
async def order_processing(ctx: WorkflowContext, payload: OrderPayload) -> OrderResult:
    # Step 1: Process payment
    result = await ctx.step.agent_invoke_and_wait(
        "start_order",
        order_agent.with_input(
            f"Process payment for order {payload.order_id}. "
            f"Charge customer {payload.customer_id} for ${payload.amount:.2f}."
        )
    )

    output: OrderAgentOutput = result.result
    charge_id = output.action_details.charge_id

    # Step 2: Check if fraud review is requested
    if output.action_requested == "fraud_review":
        # Suspend for human review (up to 24 hours)
        resume_data = await ctx.step.suspend(
            "fraud_review",
            data={
                "order_id": payload.order_id,
                "amount": payload.amount,
                "charge_id": charge_id,
                "message": "Please review this order for fraud",
            },
            timeout=86400,
        )

        if not resume_data.get("data", {}).get("approved", False):
            return OrderResult(status="rejected", charge_id=charge_id)

        # Fraud approved - send confirmation
        await ctx.step.agent_invoke_and_wait(
            "send_confirmation",
            order_agent.with_input(
                f"Fraud review APPROVED for order {payload.order_id}. "
                f"Send confirmation email to {payload.customer_email}."
            )
        )

        return OrderResult(
            status="completed",
            charge_id=charge_id,
            fraud_review_required=True,
            fraud_approved=True,
        )

    # No fraud review needed - agent already sent confirmation
    return OrderResult(status="completed", charge_id=charge_id)

git clone https://github.com/polos-dev/polos.git
cd polos/python-examples/17-order-processing
cp .env.example .env
uv sync
python worker.py      # Terminal 1
python main.py        # Terminal 2