USDA NASS Quick Stats API and bulk files

Use in your agent

Load USDA NASS Quick Stats into pandas and Parquet. Checked against the provider's documentation on Nov 1, 2026.

Access

• Request a free Quick Stats API key with a valid email address and accept the NASS API terms.
• Set the key in NASS_API_KEY; do not put it in source code.
• Large compressed subject and Census files are downloadable without an API key.

Request

curl -G 'https://quickstats.nass.usda.gov/api/api_GET/' -H 'Accept: application/json' --data-urlencode "key=$NASS_API_KEY" --data-urlencode 'commodity_desc=CORN' --data-urlencode 'year__GE=2025' --data-urlencode 'state_alpha=VA' --data-urlencode 'format=JSON'

Format

JSON object with a data array; CSV and XML are also supported. Rows include source, sector, commodity, statistic, unit, value, geography, year, frequency, reference period and load time.

Load into pandas and Parquet

Needs Python 3 with requests, pandas and pyarrow.

"""USDA NASS Quick Stats corn estimates -> pandas -> Parquet."""
import os
import requests
import pandas as pd

URL = "https://quickstats.nass.usda.gov/api/api_GET/"
params = {
    "key": os.environ["NASS_API_KEY"],
    "commodity_desc": "CORN",
    "year__GE": "2025",
    "state_alpha": "VA",
    "format": "JSON",
}
r = requests.get(URL, params=params, timeout=60)
r.raise_for_status()
df = pd.DataFrame(r.json()["data"])
df["load_time"] = pd.to_datetime(df["load_time"], errors="coerce")
df.to_parquet("usda_nass_quick_stats.parquet", index=False)
print(len(df), "Quick Stats rows", df["year"].min(), "to", df["year"].max())

Not run: it needs a free API key.

Limits

• Rate limit: Not stated.
• Each API request returns at most 50,000 records.
• Use get_counts before a pull; split oversized calls or use the compressed bulk files.

Quirks

• Value is formatted text and can contain commas or suppression markers; clean it deliberately rather than coercing the full column blindly.
• The same column set is used in API output and the tab-delimited bulk products.
• Chemical-use records encode the type of chemical in domain fields; keep domain_desc and domaincat_desc.

Terms and attribution

• Use of the API constitutes acceptance of the NASS API terms.
• Applications using the API should display the required non-endorsement notice.
• Do not modify or falsely represent API content and continue to claim NASS as its source.

Sources

• https://quickstats.nass.usda.gov/api: “Your request will return a maximum of 50,000 data records.”
• https://quickstats.nass.usda.gov/api: “The api_GET resource supports three different output formats: JSON(default), XML or CSV.”
• https://quickstats.nass.usda.gov/api: “You may use the NASS API to develop a service to search, display, analyze, retrieve, view and otherwise 'get' information from NASS data”
• https://www.nass.usda.gov/datasets/: “Download agricultural statistics large datasets using .gz files.”