Funds

What is actually left in the ad account, before anything is launched.

The numbers already existed — pipeline/funds_reader.py reads both providers for the daily low-balance sweep — but nothing exposed them to the customer, so the flow could create a campaign, turn it on, and leave it sitting in an account with no money behind it. The provider says nothing: it accepts the campaign and simply never serves.

Reported, never judged. balance_micros is null for an account with no prepaid balance to read — a Google account on monthly invoicing has none, and neither does one whose budget could not be read — and those two are indistinguishable from here, so this says null and the screen says it cannot tell rather than inventing a zero.

tax_rate is the sales tax the provider adds on top of every figure its API reports, so the caller can print the number the provider's own billing screen prints. India's 18% GST on ad spend is the case that matters: ₹3,000 loaded is ₹2,542 of deliverable spend.