Scientific Skill: Usfiscaldata

# 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

```python
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}")
```

```python
# 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`

```python
# 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/historical_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 | `/v2/accounting/od/i_bond_interest_rates` | Semi-Annual |
| U.S. Treasury Savings Bonds: Issues, Redemptions & Maturities | `/v1/accounting/od/sb_issues_redemptions` | Monthly |

## Response Structure

```json
{
  "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

```python
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:

```python
# 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](references/api-basics.md)** — URL structure, HTTP methods, versioning, data types
- **[parameters.md](references/parameters.md)** — All parameters with detailed examples and edge cases
- **[datasets-debt.md](references/datasets-debt.md)** — Debt datasets: Debt to the Penny, Historical Debt, Schedules of Federal Debt, TROR
- **[datasets-fiscal.md](references/datasets-fiscal.md)** — Daily Treasury Statement, Monthly Treasury Statement, revenue, spending
- **[datasets-interest-rates.md](references/datasets-interest-rates.md)** — Average interest rates, exchange rates, TIPS/CPI, certified interest rates
- **[datasets-securities.md](references/datasets-securities.md)** — Treasury auctions, savings bonds, SLGS, buybacks
- **[response-format.md](references/response-format.md)** — Response objects, error handling, pagination, response codes
- **[examples.md](references/examples.md)** — Python, R, and pandas code examples for common use cases

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