The US national debt just crossed $36 trillion. I wanted to see exactly when it happened, so I built a tracker using the Treasury's free API.
Turns out, the US government has a surprisingly good API.
The API
FiscalData.Treasury.gov — free, no API key, no signup.
Track National Debt
import requests
def get_national_debt(days=10):
url = "https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v2/accounting/od/debt_to_penny"
params = {
"sort": "-record_date",
"page[size]": days,
"fields": "record_date,tot_pub_debt_out_amt"
}
data = requests.get(url, params=params).json()
for record in data["data"]:
debt = float(record["tot_pub_debt_out_amt"])
print(f"{record["record_date"]}: ${debt/1e12:.4f} trillion")
get_national_debt()
# 2025-03-20: $36.2184 trillion
# 2025-03-19: $36.2157 trillion
Treasury Auction Results
Want to know what interest rate the government is paying on new debt?
def get_auctions(security_type="Bill", limit=5):
url = "https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/od/auctions_query"
params = {
"filter": f"security_type:eq:{security_type}",
"sort": "-auction_date",
"page[size]": limit,
"fields": "auction_date,security_term,high_investment_rate"
}
data = requests.get(url, params=params).json()
for record in data["data"]:
print(f"{record["auction_date"]} | {record["security_term"]} | Rate: {record["high_investment_rate"]}%")
get_auctions()
Government Revenue vs Spending
def monthly_budget():
url = "https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/mts/mts_table_5"
params = {
"sort": "-record_date",
"page[size]": 12,
"fields": "record_date,current_month_net,current_fytd_net"
}
data = requests.get(url, params=params).json()
for record in data["data"][:6]:
net = float(record["current_month_net"]) / 1e9
print(f"{record["record_date"]}: Monthly deficit: ${abs(net):.1f}B")
monthly_budget()
Exchange Rates
def exchange_rates(currency="Euro Zone-Euro"):
url = "https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/od/rates_of_exchange"
params = {
"filter": f"country_currency_desc:eq:{currency}",
"sort": "-record_date",
"page[size]": 6,
"fields": "record_date,exchange_rate"
}
data = requests.get(url, params=params).json()
for record in data["data"]:
print(f"{record["record_date"]}: 1 USD = {record["exchange_rate"]} EUR")
exchange_rates()
All Available Datasets
The Treasury API has 30+ datasets:
| Endpoint | What it tracks |
|---|---|
debt_to_penny | Daily national debt |
auctions_query | Treasury auction results |
mts_table_5 | Monthly budget surplus/deficit |
rates_of_exchange | Exchange rates |
avg_interest_rates | Average interest on government debt |
top_federal | Federal spending by agency |
This is Part 3 of My Government API Series
SEC EDGAR API — company financials
FRED API — economic data
Treasury API — government debt and spending (this article)
All free. All without API keys (except FRED which takes 30 sec).
What would you track with this data?
I'm thinking about building a public dashboard. What metrics should it show?
Follow for more free API tutorials.
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