Tariff Change Feed

Beta

Every dated change to Chapter 99 measures, HTS lines and base rates, as a feed you can poll.

Measures starting or ending, lines established or discontinued, and base-rate changes, newest first, with citations. Filter by date range, kind and HTS code. Alerts on your own codes come next.

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At a glance

Status: Beta
Endpoints: GET /v1/tariffs/changes
Cost: 1 unit
MCP tools: tariffs_changes
Data: Tariffs dataset 1.0.0, built 2026-10-10.

Try it

Choose an endpoint and a sample, change the parameters, and send. Without a key the public demo answers the sample requests (marked demo, not counted against any quota, limited per IP address). With your key, or your account when you are signed in, any values work and the call counts against your plan. A key stays in this page's memory: it is never stored. Get a free key.

Recorded answer of the real API on the current data for this sample (long arrays trimmed).

Response 200GET/v1/tariffs/changes

{
  "data": {
    "since": "2026-09-01",
    "until": null,
    "hts": null,
    "kinds": ["measure", "hts_line", "… 1 more"],
    "total": 290,
    "count": 20,
    "offset": 0,
    "events": [
      {
        "date": "2030-08-14",
        "event": "ends",
        "kind": "measure",
        "heading": "9903.45.30",
        "rule_id": "OTH-201-QSP-INQUOTA-Y4",
        "group": "other",
        "rate_text": "19% (in quota), year 4 (2029-08-15 - 2030-08-14)",
        "countries": null,
        "citation": {
          "type": "Federal Register (presidential document / rule)",
          "id": "Proclamation 11051, 91 FR 50645 (Aug 5, 2026)",
          "url": "https://www.federalregister.gov/documents/2026/08/05/2026-15975/to-facilitate-positive-adjustment-to-competition-from-imports-of-quartz-surface-products"
        },
        "note": "last entry date it applies to"
      },
      {
        "date": "2030-08-14",
        "event": "ends",
        "kind": "measure",
        "heading": "9903.45.31",
        "rule_id": "OTH-201-QSP-OVERQUOTA-Y4",
        "group": "other",
        "rate_text": "47% (over quota), year 4 (2029-08-15 - 2030-08-14)",
        "countries": null,
        "citation": {
          "type": "Federal Register (presidential document / rule)",
          "id": "Proclamation 11051, 91 FR 50645 (Aug 5, 2026)",
          "url": "https://www.federalregister.gov/documents/2026/08/05/2026-15975/to-facilitate-positive-adjustment-to-competition-from-imports-of-quartz-surface-products"
        },
        "note": "last entry date it applies to"
      },
      "… 18 more"
    ],
    "flagged_events": [
      {
        "date": "3025-06-30",
        "kind": "hts_line",
        "event": "modified",
        "hts": "99030125",
        "htsno": "9903.01.25",
        "release": "2026HTSBasic",
        "text": "Modified June 30, 3025 Notice Rev 16",
        "citation": {
          "type": "USITC HTS Change Record",
          "url": "https://hts.usitc.gov/reststop/file?release=2026HTSBasic&filename=Change%20Record"
        }
      },
      {
        "date": "3025-06-30",
        "kind": "hts_line",
        "event": "modified",
        "hts": "99039401",
        "htsno": "9903.94.01",
        "release": "2026HTSBasic",
        "text": "Modified June 30, 3025 Notice Rev 16",
        "citation": {
          "type": "USITC HTS Change Record",
          "url": "https://hts.usitc.gov/reststop/file?release=2026HTSBasic&filename=Change%20Record"
        }
      },
      "… 4 more"
    ],
    "flagged_note": "Dated more than 10 years after the rule coverage (after 2036-10-09): as printed in the source, most likely a typo there; not sorted with the other events.",
    "coverage": { "from": "2025-01-01", "to": "2026-10-09" },
    "note": "Dated changes in this dataset version: Chapter 99 measures starting or ending (by entry date), HTS lines established, discontinued or changed (USITC Change Records) and column 1 General rate changes. …"
  },
  "meta": {
    "request_id": "req_…",
    "api_version": "1",
    "dataset": "tariffs",
    "dataset_version": "1.0.0",
    "dataset_built_at": "2026-10-10T16:05:28Z",
    "data_status": "released",
    "sources": [
      {
        "id": "usitc_harmonized_tariff_schedule_chapter",
        "name": "USITC Harmonized Tariff Schedule (Chapter 99 PDFs, Change Records, releaseList, exportList REST)",
        "url": "https://hts.usitc.gov/",
        "licence": "U.S. Government work, public domain (17 U.S.C. 105)",
        "commercial_redistribution_ok": true,
        "retrieved": "2026-10-09/2026-10-10"
      },
      {
        "id": "federal_register_proclamations_executive",
        "name": "Federal Register (proclamations, executive orders, USTR/Commerce notices)",
        "url": "https://www.federalregister.gov/",
        "licence": "U.S. Government work, public domain (17 U.S.C. 105)",
        "commercial_redistribution_ok": true,
        "retrieved": "2026-10-09/2026-10-10"
      },
      "… 3 more"
    ],
    "provenance_note": "Every value carries provenance (source, id or URL, retrieval date; method and confidence where an AI judged). Calculations list their inputs and method.",
    "disclaimer": "Reference data and calculations from HTS codes you supply. Not classification advice and not a filing: entry filings need a licensed customs broker (CBP HQ H350722).",
    "usage": "…"
  }
}

1Pin and diff: the version is also in the X-Dataset-Version header

curlGET/v1/tariffs/changes

curl -s "https://api.htscalculator.com/demo/v1/tariffs/changes?since=2026-09-01&limit=20"

Endpoints

Endpoints of the Tariff Change Feed
Endpoint	What it does	Cost	MCP tool	Documentation
GET /v1/tariffs/changes	Tariff change feed	1 unit	tariffs_changes	Docs

What is included

Measures starting and ending by entry date, with the first citation
HTS line events from the USITC Change Records
Base-rate changes between releases
Watchlists, email alerts and webhooks Coming soon

How it differs

Dated by when the change applies to entries, not by when we noticed it.
Each event carries its citation.
The same data the duty stack uses, so the feed and the calculation agree.

Plans

One key and one plan cover every HTS Calculator product, this one included. Free: 2,500 units a month (2,500 calls of /v1/tariffs/changes). Developer $49 and Pro $249 a month. Caching inside your product is allowed, and so is use by AI agents. Plans and units.

Status: Beta (new: the interface may still change, with notice in the docs). All products.