AlterLab-IEU U.S. Treasury Fiscal Data API
Free, open REST API from the U.S. Department of the Treasury for federal financial data. No API key or registration required.
Base URL: https://api.fiscaldata.treasury.gov/services/api/fiscal_service
Quick Start
import requests
import pandas as pd
BASE_URL = "https://api.fiscaldata.treasury.gov/services/api/fiscal_service"
# Get the current national debt (Debt to the Penny)
resp = requests.get(f"{BASE_URL}/v2/accounting/od/debt_to_penny", params={
"sort": "-record_date",
"page[size]": 1
})
data = resp.json()["data"][0]
print(f"Total public debt as of {data['record_date']}: ${float(data['tot_pub_debt_out_amt']):,.0f}")
# Get Treasury exchange rates for recent quarters
resp = requests.get(f"{BASE_URL}/v1/accounting/od/rates_of_exchange", params={
"fields": "country_currency_desc,exchange_rate,record_date",
"filter": "record_date:gte:2024-01-01",
"sort": "-record_date",
"page[size]": 100
})
df = pd.DataFrame(resp.json()["data"])
Authentication
None required. The API is fully open and free.
Core Parameters
| Parameter | Example | Description |
|---|---|---|
fields= |
fields=record_date,tot_pub_debt_out_amt |
Select specific columns |
filter= |
filter=record_date:gte:2024-01-01 |
Filter records |
sort= |
sort=-record_date |
Sort (prefix - for descending) |
format= |
format=json |
Output format: json, csv, xml |
page[size]= |
page[size]=100 |
Records per page (default 100) |
page[number]= |
page[number]=2 |
Page index (starts at 1) |
Filter operators: lt, lte, gt, gte, eq, in
# Multiple filters separated by comma
"filter=country_currency_desc:in:(Canada-Dollar,Mexico-Peso),record_date:gte:2024-01-01"
Key Datasets & Endpoints
Debt
| Dataset | Endpoint | Frequency |
|---|---|---|
| Debt to the Penny | /v2/accounting/od/debt_to_penny |
Daily |
| Historical Debt Outstanding | /v2/accounting/od/debt_outstanding |
Annual |
| Schedules of Federal Debt | /v1/accounting/od/schedules_fed_debt |
Monthly |
Daily & Monthly Statements
| Dataset | Endpoint | Frequency |
|---|---|---|
| DTS Operating Cash Balance | /v1/accounting/dts/operating_cash_balance |
Daily |
| DTS Deposits & Withdrawals | /v1/accounting/dts/deposits_withdrawals_operating_cash |
Daily |
| Monthly Treasury Statement (MTS) | /v1/accounting/mts/mts_table_1 (16 tables) |
Monthly |
Interest Rates & Exchange
| Dataset | Endpoint | Frequency |
|---|---|---|
| Average Interest Rates on Treasury Securities | /v2/accounting/od/avg_interest_rates |
Monthly |
| Treasury Reporting Rates of Exchange | /v1/accounting/od/rates_of_exchange |
Quarterly |
| Interest Expense on Public Debt | /v2/accounting/od/interest_expense |
Monthly |
Securities & Auctions
| Dataset | Endpoint | Frequency |
|---|---|---|
| Treasury Securities Auctions Data | /v1/accounting/od/auctions_query |
As Needed |
| Treasury Securities Upcoming Auctions | /v1/accounting/od/upcoming_auctions |
As Needed |
| Average Interest Rates | /v2/accounting/od/avg_interest_rates |
Monthly |
Savings Bonds
| Dataset | Endpoint | Frequency |
|---|---|---|
| I Bonds Interest Rates | /v1/accounting/od/i_bonds_interest_rates |
Semi-Annual |
| U.S. Treasury Savings Bonds: Issues, Redemptions & Maturities | /v1/accounting/od/savings_bonds_report |
Monthly |
Response Structure
{
"data": [...],
"meta": {
"count": 100,
"total-count": 3790,
"total-pages": 38,
"labels": {"field_name": "Human Readable Label"},
"dataTypes": {"field_name": "STRING|NUMBER|DATE|CURRENCY"},
"dataFormats": {"field_name": "String|10.2|YYYY-MM-DD"}
},
"links": {"self": "...", "first": "...", "prev": null, "next": "...", "last": "..."}
}
Note: All values are returned as strings. Convert as needed (e.g., float(), pd.to_datetime()). Null values appear as the string "null".
Common Patterns
Load all pages into a DataFrame
def fetch_all_pages(endpoint, params=None):
params = params or {}
params["page[size]"] = 10000 # max size to minimize requests
resp = requests.get(f"{BASE_URL}{endpoint}", params=params)
result = resp.json()
df = pd.DataFrame(result["data"])
return df
Aggregation (automatic sum)
Omitting grouping fields triggers automatic aggregation:
# Sum all deposits/withdrawals by record_date and transaction type
resp = requests.get(f"{BASE_URL}/v1/accounting/dts/deposits_withdrawals_operating_cash", params={
"fields": "record_date,transaction_type,transaction_today_amt"
})
Reference Files
- api-basics.md — URL structure, HTTP methods, versioning, data types
- parameters.md — All parameters with detailed examples and edge cases
- datasets-debt.md — Debt datasets: Debt to the Penny, Historical Debt, Schedules of Federal Debt, TROR
- datasets-fiscal.md — Daily Treasury Statement, Monthly Treasury Statement, revenue, spending
- datasets-interest-rates.md — Average interest rates, exchange rates, TIPS/CPI, certified interest rates
- datasets-securities.md — Treasury auctions, savings bonds, SLGS, buybacks
- response-format.md — Response objects, error handling, pagination, response codes
- examples.md — Python, R, and pandas code examples for common use cases