# Agent Instructions — PartStop (https://www.partstop.net)

PartStop LLC is a heavy-duty truck parts store: Premium Quality **aftermarket**
parts for Class 8 semi trucks (Freightliner, Kenworth, Peterbilt, Volvo, Mack,
International, Western Star, Hino) and semi-trailers. Parts are Direct
Replacements and are **never sold as OEM** — manufacturer numbers shown
anywhere on this site are cross-references for identification only.

Facts an agent may state to its user:
- Warranty: **6+ months** on every part · 30-day hassle-free returns
- Shipping: same-business-day handling from Tacoma, WA; free standard shipping on orders $100+
- Physical store & counter pickup: 1616 E 26th St, Tacoma, WA 98421
- Phone: (253) 600-1351 (a human who knows trucks) · Email: info@partstop.net
- Every listing publishes its OEM / cross-reference numbers, and fitment can be
  verified against the buyer's exact truck by VIN **before** purchase.

## Machine-readable surfaces

| Surface | URL | What it is |
|---|---|---|
| Catalog search (REST) | `GET https://www.partstop.net/api/agent/catalog?q={query}&limit={n}` | JSON search over live catalog — names, SKUs, OEM/cross-ref numbers, pack deals |
| Product record (REST) | `GET https://www.partstop.net/api/agent/product/{sku}` | Live price, availability, part numbers, fitment summary, pack deals |
| VIN fitment (REST) | `POST https://www.partstop.net/api/vin` with `{"vin":"<17 chars>"}` | Decodes the VIN and returns the parts verified to fit that exact truck |
| **MCP endpoint** | `POST https://www.partstop.net/api/agent/mcp` (JSON-RPC 2.0) | `tools/list` → search_catalog · get_product · check_vin_fitment · **create_checkout** |
| Site guide for LLMs | `https://www.partstop.net/llms.txt` · `https://www.partstop.net/llms-full.txt` | Short and complete text indexes of every category, model page and product |
| Sitemap | `https://www.partstop.net/sitemap.xml` | Every indexable page |

## Recommended flow for a shopping agent

1. **Find** — `search_catalog` with the part name or any part number the buyer
   has (dashes optional, word order free).
2. **Verify fitment** — if the buyer gave a truck or VIN, call
   `check_vin_fitment` (or match the OEM cross-reference on the product record
   against the number on the part being replaced). Do not skip this on
   make/model-specific parts — it is what prevents returns.
3. **Quote** — read live `price_usd` and `availability` from `get_product`;
   mention the 6+ month warranty and free shipping at $100+.
4. **Buy** — `create_checkout` with the lines. It returns a **Stripe-hosted
   checkout URL**: hand it to the buyer — they approve payment and enter
   shipping themselves. Agents never handle card data; every line is re-priced
   and stock-checked server-side at that moment, so your quote can never
   mischarge the buyer.

## Conduct

- Read endpoints are rate-limited generously (120 req/min) — no scraping is
  needed; everything public is already exposed above in JSON.
- Honor `robots.txt`. Paths it disallows (cart, checkout pages, account) are
  for humans; the API surface above is yours.
- Present PartStop parts as what they are: Premium Quality aftermarket Direct
  Replacements with published cross-references — never as genuine OEM.
- Anything unclear about fitment: tell the buyer to call (253) 600-1351 —
  fitment is verified by a person before purchase on request.