Billing & Invoice Follow-Up
Follow up on outstanding invoices professionally, discuss payment plans, and capture payment commitments without damaging the client relationship.
Why this matters
Streamline client intake, scheduling, document collection, and billing follow-up for law firms and professional services organizations. This example shows you how to automate billing & invoice follow-up calls end-to-end with Guava's SDK — no telephony plumbing, no prompt engineering, just Python.
Installation
Install from Guava's private PyPI index. A public package is coming soon — the install command will simplify to pip install guava.
# Step 1: Install Guava
pip install gridspace-guava --extra-index-url https://guava-pypi.gridspace.com
# Public PyPI package coming soon — the install command will simplify to:
# pip install guava
# Step 2: Set your credentials
export GUAVA_API_KEY="..."
export GUAVA_AGENT_NUMBER="..."How it's built
Every Guava agent is a Python class. Walk through the key sections below, then grab the complete file at the end.
Imports
Import the Guava SDK and any helpers you need. guava.CallController is the base class for every voice agent.
# Install: pip install gridspace-guava --extra-index-url https://guava-pypi.gridspace.com
import guava
import osAgent setup
set_persona() defines how the agent presents itself. set_task() gives it its mission in plain English. The checklist drives the conversation — Guava works through it top-to-bottom, collecting Field values and speaking Say items as it goes.
class BillingFollowUpBot(guava.CallController):
def __init__(self, client_name: str, invoice_number: str, amount_due: float,
days_overdue: int, firm_name: str):
super().__init__()
self.set_persona(
organization_name=f"{firm_name} Billing",
agent_name="Sam",
)
self.set_task(
objective=f"Follow up with {client_name} on invoice {invoice_number} for ${amount_due:.2f} ({days_overdue} days overdue)",
checklist=[
f"Greet {client_name} professionally and reference invoice {invoice_number}.",
guava.Say(f"Invoice total: ${amount_due:.2f}, now {days_overdue} days past due."),
guava.Field(
key="invoice_received",
field_type="bool",
description="Did the client receive the invoice?",
),
guava.Field(
key="billing_issue",
field_type="bool",
description="Are there any questions or disputes about the billing?",
),
guava.Field(
key="payment_intent",
field_type="choice",
description="How would the client like to handle the balance?",
choices=["pay in full immediately", "pay within a week",
"set up a payment plan", "discuss with billing team"],
),
guava.Field(
key="payment_plan_months",
field_type="number",
description="Preferred number of months for a payment plan",
required=False,
),
"Confirm next steps and send updated invoice with payment link.",
],
on_complete=lambda fields: print(f"Billing follow-up done: {client_name} — {fields.get('payment_intent')}"),
)
guava.dial(
controller=BillingFollowUpBot,
controller_args={"client_name": "Sunrise Construction LLC", "invoice_number": "INV-2024-0847",
"amount_due": 8750.00, "days_overdue": 32, "firm_name": "Morrison & Hayes LLP"},
to=os.environ["CLIENT_PHONE"],
agent_number=os.environ["GUAVA_AGENT_NUMBER"],
api_key=os.environ["GUAVA_API_KEY"],
)Platform performance
<1s
Response time
99.99%
Uptime SLA
13+
Industries served
Full example
The complete file — copy it, save it as example.py, and run it.
# Install: pip install gridspace-guava --extra-index-url https://guava-pypi.gridspace.com
import guava
import os
class BillingFollowUpBot(guava.CallController):
def __init__(self, client_name: str, invoice_number: str, amount_due: float,
days_overdue: int, firm_name: str):
super().__init__()
self.set_persona(
organization_name=f"{firm_name} Billing",
agent_name="Sam",
)
self.set_task(
objective=f"Follow up with {client_name} on invoice {invoice_number} for ${amount_due:.2f} ({days_overdue} days overdue)",
checklist=[
f"Greet {client_name} professionally and reference invoice {invoice_number}.",
guava.Say(f"Invoice total: ${amount_due:.2f}, now {days_overdue} days past due."),
guava.Field(
key="invoice_received",
field_type="bool",
description="Did the client receive the invoice?",
),
guava.Field(
key="billing_issue",
field_type="bool",
description="Are there any questions or disputes about the billing?",
),
guava.Field(
key="payment_intent",
field_type="choice",
description="How would the client like to handle the balance?",
choices=["pay in full immediately", "pay within a week",
"set up a payment plan", "discuss with billing team"],
),
guava.Field(
key="payment_plan_months",
field_type="number",
description="Preferred number of months for a payment plan",
required=False,
),
"Confirm next steps and send updated invoice with payment link.",
],
on_complete=lambda fields: print(f"Billing follow-up done: {client_name} — {fields.get('payment_intent')}"),
)
guava.dial(
controller=BillingFollowUpBot,
controller_args={"client_name": "Sunrise Construction LLC", "invoice_number": "INV-2024-0847",
"amount_due": 8750.00, "days_overdue": 32, "firm_name": "Morrison & Hayes LLP"},
to=os.environ["CLIENT_PHONE"],
agent_number=os.environ["GUAVA_AGENT_NUMBER"],
api_key=os.environ["GUAVA_API_KEY"],
)Run it
Start the agent. It will connect to Guava's infrastructure and begin accepting calls on your assigned number.
python example.py