An AI agent can quote US import duty for you if it has a tool that computes it. It should not work the duty out on its own: a rate read from memory misses the Chapter 99 trade remedies that stack on top of it, and on the worked entry below those remedies are $16,562.50 of a $17,660.20 duty bill. This guide connects an agent to a duty MCP server, sends a two-line entry, and reads the answer line by line.
MCP (Model Context Protocol) is the standard way agents such as Claude, Cursor, Codex and Gemini CLI call outside tools. A remote MCP server is one URL. You add it once, and you sign in once in the browser.
claude mcp add --transport http vectelos https://mcp.vectelos.com/mcp,
then /mcp to sign in.https://mcp.vectelos.com/mcp.The first call opens a sign-in page. Prove your email, and the account starts with 100 free duty checks. A check is one line computed.
Duty turns on four facts. Put them in the request rather than leaving the agent to infer them:
The prompt used for the worked example:
Using the Vectelos Duty tools, compute the US import duty for this ocean shipment as one customs entry:
1. HTS 8708.30.50 (brake parts), origin China, customs value USD 42,500
2. HTS 0207.14.00 (frozen chicken cuts), origin Brazil, customs value USD 5,000, quantity 200 kg
Show each line's base rate, base duty and any trade remedies, then the entry's MPF, HMF and total payable.The agent calls compute_entry_duty. Each line returns its base duty and a list of
Chapter 99 remedies, each with the heading to report and the U.S. note behind it.
| Component | Provision | Rate | Duty |
|---|---|---|---|
| Base (column 1 general) | 8708.30.50 | 2.5% | $1,062.50 |
| Section 301, China | 9903.88.03, note 20(f) | 25% | $10,625.00 |
| Section 232, derivative aluminum articles | 9903.82.10, note 16(c)(ix) | 12.5% | $5,312.50 |
| Section 301 country-wide, excluded | 9903.05.90, note 52 | 0% | $0.00 |
| Line total | 40% | $17,000.00 |
The base rate is 2.5%; the line pays 40%. Three separate measures apply, and the fourth row is reported at zero because note 52 stands down where Section 232 already applies. A landed-cost model with one duty column would have used $1,062.50.
| Component | Provision | Rate | Duty |
|---|---|---|---|
| Base (column 1 general) | 0207.14.00 | 17.6¢/kg | $35.20 |
| Section 301 country-wide, Brazil | 9903.05.27, note 52 | 12.5% | $625.00 |
| Line total | $660.20 |
A per-kilogram rate needs the weight. 200 kg at 17.6¢ is $35.20; the ad valorem remedy on the $5,000 value is almost eighteen times that.
| Entry total | Basis | Amount |
|---|---|---|
| Customs value | 2 lines | $47,500.00 |
| Base duty | $1,097.70 | |
| Trade remedies (Chapter 99) | $16,562.50 | |
| Duty | 37.18% of value | $17,660.20 |
| Merchandise processing fee (MPF) | 0.3464%, min $32.71, max $634.62 per entry; 19 CFR 24.23 | $164.54 |
| Harbor maintenance fee (HMF) | 0.125%, vessel cargo only; 19 CFR 24.24 | $59.38 |
| Total payable | $17,884.12 |
compute_entry_duty)
when the lines ship together. For a product list that is not one shipment, the line tool
(compute_line_duties) returns lines without fees.Send the chicken line without its weight and it comes back refused:
duty_computed: false
base_duty_usd: null
duty_refusal_code: QUANTITY_REQUIRED
duty_note: Rate '17.6¢/kg' is charged per kg; quantity is required and was not supplied.
The HTSUS reports this line in kg.QUANTITY_UNIT_MISMATCH (weight given, rate
charged per item), UNPARSED_RATE (a rate split across components, such as a watch's
case, strap and battery), RELATIVE_RATE (a rate stated relative to another
subheading).Classification is a judgement about the goods, and a good one needs a person to check it. That is why the duty server leaves it out, and why it has its own place:
The app is free for 25 invoice analyses a month and has its own account, separate from the MCP server.
2026HTSRev18. The
schedule moved seven times in the eight weeks to 9 September 2026.get_schedule_revision
is free and returns the revision and the date it was verified.expect_hts_revision in automated runs to get an error, not
an answer, from a revision you have not reviewed.Where Vectelos fits. The Vectelos Duty MCP server is the engine behind every figure above, reached from your agent. It computes each Chapter 99 measure from the statutory notes, names the heading and note behind each, and refuses rather than guesses. 100 checks are free per verified email.
No codes yet? The Vectelos app classifies the lines of a supplier document for your review, then computes the same duty stack.
The two-line entry was sent to the engine on 27 September 2026 as an ocean shipment, and the refused line as a separate single-line request; the figures are the engine's output, unrounded. Section 301 product exclusions, the Section 232 metal-weight test and note 52 conditional exemptions are not applied, so the remedy figures are base coverage and an exclusion may reduce them.
This guide is general information about the US tariff schedule and one tool that computes from it. It is not legal advice, not a customs ruling and not a determination about your goods. Vectelos is not a licensed customs broker and does not file entries; the importer of record remains responsible for each entry. Confirm with a licensed customs broker before relying on any duty figure.