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Tariff & HS Code Duty Finder in ChatGPT

HS codes, customs duty & tax. The MCP server is https://tariffs.openkrill.app/mcp. No key. The steps below are only for ChatGPT. A call to get_duty_rate was checked against that server on 2026-10-17.

Connection
Streamable HTTP
API key
None needed
Rate limit
60 calls a minute
Protocol
MCP 2024-11-05

Questions it answers

Find an HS code, HTS code or customs code, and read the customs duty or import tax. Ask "what is the tariff code for a ceramic flower pot in the UK?", "what is the US duty on HTS 8507.60.00?" or "what duty applies to code 6914100000 from Vietnam in the UK?".

Tariff and HS Code Duty Finder reads the official schedules published by governments: the UK Trade Tariff (HM Revenue & Customs) and the US Harmonized Tariff Schedule (US International Trade Commission). Describe the product and it lists the codes whose descriptions match, with the headings above each one so a line that only says "Other" can be read in context. Give a code and it returns the description, the duty rate and, for the UK, the VAT rate, the preferential rate for the country the goods come from and other measures that apply. People also call it Tariff Code Finder.

Use it for a Harmonized System code, an HTS classification or a customs classification. Schedule B export codes often share the first digits of an HTS code, but this tool reads the import schedules, not the Schedule B export list. It does not search the EU TARIC list.

The codes it finds are candidates, not a classification. Which code is right depends on what the product is, what it is made of and how it is used, and customs decides. Check a candidate against the schedule's notes and confirm with customs or a licensed customs broker before you declare goods. For a binding answer, ask customs for a ruling.

The duty it shows is the rate in the schedule for that code. It does not add every extra duty, quota, anti-dumping measure or trade remedy. For the US, additional duties under chapter 99 of the schedule are not included. Rates change on published dates, so check the schedule on the day you ship.

It covers imports into the United Kingdom and the United States only. It stores nothing about you: answers are cached for up to 6 hours, and the only lasting record is a daily count of calls per tool.

Short questions this server answers, each with a direct answer: HS Code Finder and US or UK Import Duty Rate Lookup.

What it can do

  • Finds candidate HS codes, HTS codes and customs codes for a described product in the UK or US schedule
  • Shows the headings above each candidate, so lines called Other can be read in context
  • Reads the customs duty and import tax rate for a UK or US tariff code
  • Shows UK VAT, the preferential rate for an origin country and other measures on a code
  • Lists the lines under a heading when a code is not one goods are declared under
  • Labels every code as a candidate to check with customs, not a binding classification

Tools

  • find_tariff_codes, Find an HS code, HTS or customs code. Use this when the user asks for the tariff code, commodity code, customs code, HS code, HTS code, Harmonized System code or customs classification for a product, for example "what is the tariff code for a ceramic flower pot in the UK?", "HTS code for a lithium-ion battery" or "which heading covers cotton t-shirts for import into the US?". Pass a plain description of the product and country GB (United Kingdom) or US (United States). Returns candidate codes from the official schedule, each with its description, the headings above it and whether goods are declared under it, plus a notice that they are candidates and not a binding classification. Do not use it to classify goods with certainty, to give a binding customs ruling, to compute shipping or landed cost, or for countries other than GB and US.
  • get_duty_rate, Get customs duty, tariff and import tax. Use this when the user asks what import duty, customs duty, tariff, import tax or VAT applies to a tariff code or HS code, for example "what is the US duty on HTS 8507.60.00?", "what duty applies to UK commodity code 6914100000 from Vietnam?" or "what is under heading 6914 in the UK tariff?". Pass the code (4 to 10 digits, dots allowed), country GB or US, and originCountry when the user names where the goods come from. For a code goods are declared under it returns the description and the rate: for the UK the third-country duty, VAT rates as a list, the preferential rate and any additional duty for the origin, and other measures; for the US the general, special and column 2 rates and units. For a code that is only a heading it returns the lines beneath it instead. Chapter 99 additional duties for the US and quotas or trade remedies are not included. Do not use it for a landed cost estimate, for excise or customs-broker fees, or for legal advice.

Add Tariff & HS Code Duty Finder in ChatGPT

ChatGPT does not read a local config file. A custom MCP server is added in the product, and only after developer mode is on. These steps were checked against OpenAI's plugin connect guide and the ChatGPT MCP guide on 2026-10-01. Developer mode can be hidden by a workspace policy, so a Team or Enterprise admin may have to allow it first.

  1. Open ChatGPT settings, then Security and login, and turn on Developer mode.
  2. Open ChatGPT plugins and select the plus button.
  3. Enter a name such as "Tariff & HS Code Duty Finder" and a one-line description of what you want it to answer.
  4. Under Connection, choose the public endpoint and paste this URL. Include the /mcp path. Do not add a tunnel id: this server is already public.
    https://tariffs.openkrill.app/mcp
  5. Create the connection and review the tools ChatGPT lists. You should see find_tariff_codes, get_duty_rate. The feedback tools on the same server are optional and not required for the lookup.
  6. Start a new conversation, add the connection from the tools menu, and ask: What are candidate tariff codes for a ceramic flower pot in the UK?

No API key and no OAuth client id are required. The server answers without a login. Calls are limited per network and per day, and a limit comes back as a tool error rather than a partial answer. If the tool list is stale after a server change, open the connection and select Refresh, then start a new conversation.

The ChatGPT desktop app, Codex CLI and IDE extension share a different config. In the desktop app, open Settings, then MCP servers, choose Add server, select Streamable HTTP, and paste the same URL. In ~/.codex/config.toml the equivalent is a table named mcp_servers.tariffs with url = "https://tariffs.openkrill.app/mcp". ChatGPT on the web does not read that file. A published directory listing is also a different path: this page is the developer-mode connection, not a claim that Tariff & HS Code Duty Finder is already in the ChatGPT directory.

Treat the server as untrusted until you have read a few answers. A remote MCP server sees the arguments the model sends. Tariff & HS Code Duty Finder is read-only and documents what it sends onward on the privacy page.

If it does not work

The tool does not show up

Check that the endpoint ends in /mcp. Open the connection, select Refresh, then start a new conversation and add the connection from the tools menu. A conversation started before the connection was added does not see its tools.

429 or rate_limited

Each server takes 60 calls a minute from one network, and some tools take fewer. Past that the call comes back as a tool error that starts with rate_limited: wait a minute and ask again. daily_limit means the server reached its shared daily cap, which resets at 00:00 UTC. A limit is not an answer, so do not read it as no results. For higher limits, ask support@openkrill.app for a key.

Developer mode is missing in ChatGPT

Developer mode is in ChatGPT settings, then Security and login, on the web. In a Team or Enterprise workspace an admin can hide it, so ask the admin to allow custom connections first. Without developer mode ChatGPT cannot add a custom MCP server.

A call checked on 2026-10-17

HTS 8507.60.00 is the lithium-ion battery heading named in the plugin's starter prompts. The rate is a schedule reading, not a classification. The request below was posted to https://tariffs.openkrill.app/mcp as tools/call. HTTP 200. Source: the Tariff & HS Code Duty Finder server, read 2026-10-17.

{
  "method": "tools/call",
  "params": {
    "name": "get_duty_rate",
    "arguments": {
      "code": "8507.60.00",
      "country": "US"
    }
  }
}
  • source. Harmonized Tariff Schedule of the United States (hts.usitc.gov), published by the US International Trade Commission.
  • country. US
  • notice. These are candidate codes from the official tariff, not a binding classification. The right code depends on what the product is, what it is made of and how it is used; confirm with customs or a licensed customs broker be

Repeat the call yourself if you need a newer reading. Cached answers expire. A rate limit is not a result: wait and try again. Nothing in the call is a ranking, a filing, or advice.

Using it in production

Nothing to install and nothing to run: no package, no Python or Node.js version and no environment variable. Tariff & HS Code Duty Finder runs on our servers, and your client only needs the URL https://tariffs.openkrill.app/mcp.

Rate limit60 tool calls a minute from one network. initialize and tools/list do not count.
Daily cap25000 tool calls a day per server, shared by every caller. It resets at 00:00 UTC.
At a limitThe call comes back as a tool error that starts with rate_limited (wait a minute) or daily_limit (try after 00:00 UTC), never as a partial answer.
KeyNone. Do not add an Authorization header or a key field.
Higher limitsEmail support@openkrill.app with the server name, the calls a day you expect and what they are for. We answer within 1 business day.
FreshnessSome answers come from a short cache. Each guide shows the date of its checked call; repeat a call when you need a newer reading.
UptimeScheduled test calls check the servers through the same endpoint. There is no SLA yet.
DataWhat each server receives and keeps is on the privacy page.

Use it in other apps

Roles that use Tariff & HS Code Duty Finder

Frequently asked questions

How do I install the Tariff & HS Code Duty Finder MCP server in ChatGPT?

Turn on Developer mode in ChatGPT settings, then Security and login. In ChatGPT plugins, select the plus button and paste https://tariffs.openkrill.app/mcp as the public endpoint. Start a new conversation and add the connection from the tools menu.

Do I need an API key to run Tariff & HS Code Duty Finder in ChatGPT?

No. This server takes no API key. For higher limits, email support@openkrill.app with the server name (Tariff & HS Code Duty Finder), the calls a day you expect and what they are for. We answer within 1 business day.

What should I do if Tariff & HS Code Duty Finder does not connect in ChatGPT?

Check that the endpoint ends in /mcp. Open the connection, select Refresh, and start a new conversation. If Developer mode is missing, a workspace admin has to allow it first.

Words on this page

Source: plugin listing for tariffs in this repository, and a live tools/call on 2026-10-17. As of 2026-10-17.