Chase Invoices Without Chasing Your Tail

import requests
from datetime import datetime

API = "https://api.multimail.dev/v1"
HEADERS = {"Authorization": "Bearer mm_live_xxx"}

def process_overdue_invoices(invoices: list):
    today = datetime.utcnow().date()

    for inv in invoices:
        if inv["status"] == "paid":
            continue

        days_overdue = (today - inv["due_date"]).days
        if days_overdue <= 0:
            continue

        "cm"># Check client payment history
        contact = requests.get(
            f"{API}/contacts/search",
            headers=HEADERS,
            params={"email": inv["contact_email"]}
        ).json()

        tone = select_tone(days_overdue, contact)
        body = draft_follow_up(inv, tone, days_overdue)

        requests.post(
            f"{API}/send",
            headers=HEADERS,
            json={
                "from": "[email protected]",
                "to": inv["contact_email"],
                "subject": f"Invoice "cm">#{inv['number']} is {days_overdue} days past due - ${inv['amount']:,.2f}",
                "text_body": body,
                "html_body": build_follow_up_html(inv, tone)
            }
        )

def select_tone(days_overdue: int, contact: dict) -> str:
    has_good_history = contact.get("metadata", {}).get(
        "on_time_rate", 1.0
    ) > 0.8

    if days_overdue <= 7:
        return "gentle" if has_good_history else "firm"
    elif days_overdue <= 15:
        return "firm"
    elif days_overdue <= 30:
        return "urgent"
    else:
        return "final"

def draft_follow_up(inv: dict, tone: str, days: int) -> str:
    templates = {
        "gentle": (
            f"Hi {inv[&"cm">#039;contact_name']},\n\n"
            f"I hope this finds you well. I wanted to follow up on "
            f"invoice "cm">#{inv['number']} for ${inv['amount']:,.2f}, which "
            f"was due on {inv[&"cm">#039;due_date']}. Please let us know if you "
            f"need anything to process the payment.\n\n"
            f"Payment link: {inv[&"cm">#039;payment_url']}"
        ),
        "urgent": (
            f"Dear {inv[&"cm">#039;contact_name']},\n\n"
            f"Invoice "cm">#{inv['number']} for ${inv['amount']:,.2f} is now "
            f"{days} days past due. We kindly request immediate payment "
            f"to avoid any impact to your account.\n\n"
            f"Payment link: {inv[&"cm">#039;payment_url']}\n\n"
            f"If there are any issues with this invoice, please reply "
            f"so we can resolve them promptly."
        )
    }
    return templates.get(tone, templates["gentle"])

"cm">// Using MultiMail MCP tools for invoice follow-up

async function followUpOverdueInvoice(invoice: Invoice) {
  const daysOverdue = daysBetween(invoice.dueDate, new Date());
  if (daysOverdue <= 0) return;

  "cm">// Check client payment history
  const contacts = await mcp.search_contacts({
    query: invoice.contactEmail
  });

  const tone = selectTone(daysOverdue, contacts[0]);

  "cm">// Send follow-up (queued for finance review)
  await mcp.send_email({
    to: invoice.contactEmail,
    subject: `Invoice #${invoice.number} is ${daysOverdue} days past due`,
    text_body: draftFollowUp(invoice, tone, daysOverdue)
  });

  "cm">// Tag for tracking
  await mcp.add_contact({
    email: invoice.contactEmail,
    metadata: {
      last_followup_date: new Date().toISOString(),
      followup_count: (contacts[0]?.metadata?.followup_count || 0) + 1
    }
  });
}