US Tariff Lookup

Profitpather Tools

Open MCP servers for ecommerce operations, hosted on Cloudflare Workers at **https://tools.profitpather.com**. No account, no API key, no sign-up.

Each server is namespaced by slug under one hostname, so adding a server is a registry entry rather than a new domain.

All four are published in the official MCP Registry under com.profitpather.tools/.

A theme runs through all of them: each one distinguishes what it knows from what it cannot see, and says so in the response. ShipRate refuses to rank across currencies because the data has no exchange rate. Business Days reports provider disagreement instead of resolving it. Storefront Check carries a not_observable list on every tool. US Tariff Lookup states what its figures exclude. A confidently wrong tool is worse than no tool.

ShipRate AU

Australian parcel shipping, quoted from two independent sources in one call.

• quote_domestic_au - domestic rates from both sources
• quote_international_from_au - outbound international rates
• lookup_au_postcode - postcode to suburb and state, or the reverse
• calculate_cubic_weight - the weight you will actually be billed on
• list_goods_categories - the fixed category enum the commercial source accepts

The two sources are not interchangeable, and the server never pretends they are. Australia Post prices come from the PAC API and are retail: a business on an eParcel or contract account pays materially less. The commercial panel is pre-negotiated pricing, a different class entirely. Every rate carries a pricing_basis saying which it is, so a lower number is never mistaken for a better carrier.

Two further rules the server holds to:

• It will not rank across currencies. The upstream data carries no exchange rate, so when more than one currency comes back the list is deliberately left unsorted and sorted_by_price is false. Nothing is summed either.
• A source that quoted nothing is reported, not hidden. source_notes always says what was missing and why, so an empty list is never silently presented as "no options exist".

calculate_cubic_weight exists because carriers bill on whichever is greater, actual or volumetric weight. A 60x40x40cm parcel weighing 2kg is billed as 24kg under the Australia Post domestic convention. It returns every common divisor with the arithmetic shown, and states its assumptions rather than implying one number is authoritative.

Business Days

Public holidays and working-day arithmetic for 200+ countries, including state and province subdivisions.

• list_public_holidays - holidays in a country or region for a year
• check_business_day - is this date a working day, and what blocks it
• add_business_days - move N working days, skipping weekends and holidays
• cross_check_holidays - compare the national list across all providers

A language model's failure mode on calendar questions is confident wrongness, and a tool that is also confidently wrong adds nothing. So holiday data is read from three independent providers and disagreements are reported rather than resolved:

Providers are compared by date, never by name, since the same day is named differently by each. A disputed date arrives as a caveat attached to the answer, not as a confident single date.

Storefront Check

Audit a public ecommerce storefront from the outside. No credentials and no cooperation from the store, so it works on a competitor or a prospect.

• detect_tracking_tags - every ad and analytics tag visible in the HTML, with ids
• check_agent_readiness - whether AI crawlers may read the store, and whether the catalogue is machine readable
• check_structured_data - JSON-LD types, parse failures and commerce markup
• audit_product_feed - Shopify catalogue health for Merchant Center and Meta feeds

It distinguishes present, absent and not observable and never conflates them. A Shopify Custom Pixel runs in a sandboxed iframe and cannot be seen from outside, so an empty tag list is not evidence a store is untagged.

The check worth knowing about: each Google measurement id is verified against Google Tag Manager, which answers 404 for an id it does not recognise. A dead id means gtag never initialises, so a store looks correctly tagged while recording nothing and a campaign can spend for months at zero conversions. A consent app carrying a stale id from an old property is the usual cause, and this failure appears nowhere else.

US Tariff Lookup

Find the right US tariff code for a product and the duty rate that governs it, read live from the official USITC Harmonized Tariff Schedule.

• find_hts_code - candidates from a plain-language product description
• lookup_us_duty_rate - the governing rate, with free-trade eligibility by origin
• estimate_us_duty - indicative duty on a customs value

Two traps it handles. Rates sit on the 8-digit line, while the 10-digit statistical lines below are blank and inherit, so reading the rate off the code you were handed looks duty-free. And duty follows the country of origin of the goods, not the seller's address: AU appears in the special column for most apparel, and for apparel the rules of origin are yarn-forward, so Australian wool spun and sewn in China is Chinese origin and pays the general rate.

Making the search usable took four fixes, each found by testing real products. The official search is an OR match returned in tariff-number order rather than by relevance, so it is re-ranked locally with terms weighted by rarity. Consumer words are translated to trade terms and the translation is reported, because the schedule matches whole words: "bra" returns nothing while "brassiere" finds heading 6212, and "leggings" returns frog legs.

Trade remedies are excluded from every figure and said to be. Section 301, Section 232, antidumping and countervailing duties all sit in Chapter 99, stack on top, and routinely exceed the base rate. Chapter 98 and 99 lines are returned in a separate list so a conditional Free rate cannot be read as the answer.

Discovery

A directory can describe either server without connecting as a client:

GET https://tools.profitpather.com/.well-known/agent-skills/index.json
GET https://tools.profitpather.com/ship/.well-known/agent-skills/index.json
GET https://tools.profitpather.com/days/.well-known/agent-skills/index.json

The hub document inlines every skill on every server, so a crawler that reads only the root still comes away with the full tool list rather than needing a second fetch it may never make.

Transport

Streamable HTTP, JSON-RPC 2.0 over POST. The servers answer with application/json and offer no SSE stream, so GET on an endpoint returns 405 with Allow: POST, OPTIONS. Notifications get 202 and no body.

Responses to tools/call are cached for 12 hours on a key covering the server, tool name and every argument, so repeating a request costs the upstream APIs nothing. There is also a crude per-IP, per-minute brake; the cache is what really protects the upstream quotas.

Running it

npm install
npx wrangler dev        # needs AUSPOST_KEY and EASYSHIP_KEY in .dev.vars
npx wrangler deploy     # needs CLOUDFLARE_ACCOUNT_ID in .env

The Cloudflare account id is deliberately not in wrangler.jsonc. Put it in a gitignored .env as CLOUDFLARE_ACCOUNT_ID=...; wrangler reads it from there. Without it, a deploy fails on any login with more than one account available.

node --check is not a sufficient gate: it accepts code that esbuild rejects. Use npx wrangler deploy --dry-run --outdir /tmp/out instead.

Limits

Rates are indicative. International prices exclude destination duty and tax. Holiday data is cached at the edge for 24 hours. Nothing here is advice, and for anything that costs money the carrier's own contract and the official government calendar govern.