Auto Parts Fitment API

    Don't build a fitment engine from scratch. Plug yours in 2 weeks

    White-label API infrastructure for auto parts e-commerce platforms. VIN decoding, OEM catalog crossover and ACES/PIES fitment validation in milliseconds — the technical layer your dev team shouldn't be maintaining.

    Maintaining an in-house fitment database costs more than you think

    If your platform sells parts and can't guarantee the customer receives the right one, the sale is already lost. The problem: maintaining a relational base of brands × years × models × engines × plants drains your dev team's critical bandwidth — and falling 6 months behind takes you out of the game.

    This API solves it from day one: the same fitment layer powering AutoParts AI Agent in LatAm dealerships, exposed as authenticated REST for your e-commerce platform, marketplace or ERP to consume directly. White-label, OEM-normalized JSON, no lock-in.

    What you get when you plug in the Fitment API

    One integration. Full OEM catalog. Zero vehicle-data maintenance.

    VIN → fitment in one call

    Send VIN + part category, receive compatible part numbers + live SSPL supersessions.

    ACES/PIES compliant

    Schema compatible with Auto Care Association standards — ready for US marketplaces.

    Real OEM coverage

    Toyota, Lexus, Nissan, Honda, Suzuki, Yamaha, Bajaj, JLR via official EPC. Zero scraping.

    <200 ms P95 latency

    Optimized so your shopping cart doesn't lose conversion to response times.

    Self-hosted optional

    Sovereign on-premise infra if your customer data can't leave your network.

    Automation templates

    Ready n8n flows and SAP/Oracle/Salesforce connectors — integration in days, not months.

    Three steps to guaranteed fitment in your e-commerce

    From customer input to cart with the right part.

    1. Customer enters VIN or plate

    JS widget or direct call from your frontend (React, Vue, Shopify, Magento, WooCommerce).

    2. API validates and crosses

    Decodes the VIN, queries the corresponding OEM EPC and applies ACES fitment rules.

    3. Returns filtered catalog

    JSON with compatible part numbers, SSPL supersessions and exploded diagram image when available.

    Why marketplaces choose this API over building in-house

    Time-to-Market from 12 months to 2 weeks. No team dedicated to OEM data maintenance.

    • A wrong part shipped costs double: the return + the customer who doesn't come back. The API eliminates that error category.
    • Public fitment bases (ACES without official EPC) cover ~60% of the fleet and lag 2–3 months behind every facelift.
    • This API updates at the OEM's pace because it's wired to the official EPC — no gap between model launch and coverage.
    • White-label model: the JSON ships with your schema, not our branding. Your customers never see the dependency.
    • Volume pricing without public tiers — technical integration starts before commercial negotiation.

    Plug your e-commerce into the fastest fitment engine on the market

    We give you a sandbox with 1,000 calls, a real decoded VIN and an hour with our technical team. No card, no commitment.

    DEVELOPER EXPERIENCE

    VIN + category → filtered catalog

    One call. ACES/PIES-compliant JSON. Ready for your cart.

    Request
    curl -X POST https://api.eitserv.tech/v1/fitment/search \
  -H "Authorization: Bearer $EITS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "vin": "JTDKARFU8K3079482",
    "category": "brake_pads_front",
    "include_aftermarket": true
  }'
    Response200 OK · 127ms
    {
  "vehicle": { "make": "Toyota", "model": "Prius", "year": 2019 },
  "category": "brake_pads_front",
  "results": [
    {
      "part_number": "04465-47080",
      "type": "oem",
      "brand": "Toyota Genuine",
      "supersedes": "04465-47070",
      "fits": "100%",
      "price_tier": "A"
    },
    {
      "part_number": "AKD2287",
      "type": "aftermarket",
      "brand": "Akebono",
      "oem_equivalent": "04465-47080",
      "fits": "100%"
    }
  ],
  "latency_ms": 184
}

    Fitment API vs building your own engine

    The real cost of "in-house" vs integrating a specialized API.

    DimensionEITS APIIn-house (public ACES)Scraping OEM
    Time-to-Market2 weeks8–12 months4–6 months
    Fleet coverage~100% (via EPC)~60%Variable
    Monthly maintenance0 dev hours40–80 h60–120 h
    Legal riskOEM agreementLowHigh (T&C)
    Response latency<200 ms~500 ms1–3 s
    Year-1 cost (estimate)$$$$$$$$$

    Fitment flow architecture

    From end-user input to validated parts in the cart.

    01

    End customer

    Enters VIN in your store (React/Shopify/Magento).

    02

    Your platform

    Authenticated call to /fitment/search endpoint.

    03

    EITS engine

    VIN decode + OEM EPC cross + category filter + ACES/PIES.

    04

    SSPL validator

    Replaces obsolete part numbers with current ones.

    05

    JSON to cart

    Filtered list with OEM + equivalent aftermarket.

    Frequently Asked Questions

    Everything you need to know before getting started.

    Related reading

    VIN Decoder API

    The decoding layer that powers fitment.

    Read

    VIN → OEM Parts API

    Dedicated VIN → OEM part number endpoint.

    Read

    AutoParts AI Agent

    Full platform using this API as engine.

    Read

    Blog: Decode VIN to parts catalog

    Technical implementation tutorial.

    Read