US Treasury Fiscal Data API Reference

Overview

The US Treasury's Fiscal Data API provides machine-readable access to federal financial data: national debt, treasury securities, interest rates, yield curves, revenue, spending, and more. Maintained by the Bureau of the Fiscal Service.

Base URL

https://api.fiscaldata.treasury.gov/services/api/fiscal_service

Authentication

No API key required. The API is fully open and public.

Rate Limits

• No formal rate limits published.
• Reasonable use expected; no authentication or throttling documented.
• For bulk data, use pagination with large page sizes.

Key Endpoints

URL Pattern

All dataset endpoints follow:

GET /services/api/fiscal_service/{endpoint}?{parameters}

Common Query Parameters (apply to all endpoints)

Filter Operators: eq (equals), lt, lte, gt, gte, in (comma-separated values)

1. Average interest rates on Treasury securities

GET /v2/accounting/od/avg_interest_rates reports average interest rates on outstanding securities. It is not the daily par yield curve. Exchange-rate records at /v1/accounting/od/rates_of_exchange are also a different dataset.

Daily Treasury yield curves are provided by the separate Treasury XML feeds. Select the par-yield dataset and year from that documentation; preserve maturity, date and yield definition rather than substituting average debt interest rates.

Example -- Average interest rates on Treasury securities:

https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v2/accounting/od/avg_interest_rates?filter=record_date:gte:2024-01-01&sort=-record_date&page[size]=100

Response:

{
  "data": [
    {
      "record_date": "2024-10-31",
      "security_type_desc": "Marketable",
      "security_desc": "Treasury Bills",
      "avg_interest_rate_amt": "5.223",
      "src_line_nbr": "1",
      "record_fiscal_year": "2025",
      "record_fiscal_quarter": "1",
      "record_calendar_year": "2024",
      "record_calendar_quarter": "4",
      "record_calendar_month": "10",
      "record_calendar_day": "31"
    }
  ],
  "meta": {
    "count": 100,
    "labels": { ... },
    "dataTypes": { ... },
    "dataFormats": { ... },
    "total-count": 1234,
    "total-pages": 13
  },
  "links": {
    "self": "&page%5Bnumber%5D=1&page%5Bsize%5D=100",
    "first": "&page%5Bnumber%5D=1&page%5Bsize%5D=100",
    "prev": null,
    "next": "&page%5Bnumber%5D=2&page%5Bsize%5D=100",
    "last": "&page%5Bnumber%5D=13&page%5Bsize%5D=100"
  }
}

2. Debt to the Penny (Daily National Debt)

GET /v2/accounting/od/debt_to_penny

Example -- Debt since 2024:

https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v2/accounting/od/debt_to_penny?filter=record_date:gte:2024-01-01&sort=-record_date&page[size]=10

Key Fields: record_date, tot_pub_debt_out_amt, intragov_hold_amt, debt_held_public_amt

3. Treasury Securities Auctions

GET /v1/accounting/od/auctions_query

Example -- Recent T-Bill auctions:

https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/od/auctions_query?filter=security_type:eq:Bill&sort=-auction_date&page[size]=10

Key Fields: cusip, security_type, security_term, auction_date, issue_date, maturity_date, high_yield, high_discount_rate, bid_to_cover_ratio, total_accepted

4. Monthly Treasury Statement (Outlays)

GET /v1/accounting/mts/mts_table_5

Example -- Federal outlays:

https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/mts/mts_table_5?filter=record_date:gte:2024-01-01&sort=-record_date&page[size]=50

5. Receipts by Source and Outlays by Function

GET /v1/accounting/mts/mts_table_9

Example:

https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/mts/mts_table_9?filter=record_date:gte:2024-01-01&sort=-record_date

6. Treasury Reporting Rates of Exchange

GET /v1/accounting/od/rates_of_exchange

Example -- Exchange rates for a quarter:

https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/od/rates_of_exchange?filter=record_date:eq:2024-09-30&page[size]=200

Key Fields: country_currency_desc, exchange_rate, record_date, effective_date

7. Interest Expense on the Debt

GET /v2/accounting/od/interest_expense

Example:

https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v2/accounting/od/interest_expense?filter=record_fiscal_year:eq:2024&sort=-record_date

8. Other datasets

Discover savings-bond and financial-statement endpoints in the current Fiscal Data catalogue; their names do not imply interchangeable rate or value series. Avoid undocumented guessed paths.

Common Endpoint Paths

Response Format

All JSON responses share the same envelope:

• data: Array of result objects
• meta: Contains count, total-count, total-pages, field labels and data types
• links: Pagination links (self, first, prev, next, last)

Notes

• All monetary amounts are returned as strings to preserve precision.
• Confirm units for each table and field; monthly statement tables are not uniformly in millions.
• Dates use YYYY-MM-DD format in the record_date field.
• For auction analysis, use auction_date; record_date describes publication.
• The filter parameter supports chaining: filter=field1:eq:val1,field2:gte:val2.
• Use fields= to reduce response size by requesting only needed columns.
• The API documentation and dataset explorer is at: https://fiscaldata.treasury.gov/api-documentation/
• For Treasury yield curve rates specifically, FRED series DGS1, DGS2, DGS5, DGS10, DGS30 may be more convenient.

Pagination links may be query fragments. Preserve the original endpoint, filters and fields while replacing page parameters. Use curl --globoff for literal square brackets, or encode parameters with --data-urlencode.