Do I need an API key to try it?

No. The sandbox needs no signup, no key and no card. The vehicle taxonomy is free to use in production, including commercially. A key only widens fitment coverage past the six sandbox makes.

Where does the fitment data come from?

Manufacturer application guides published by Metra, Connects2, PAC, Scosche, Crux, Aerpro, iDatalink and CARAV, normalized against one vehicle list so a single query returns every compatible part regardless of which brand published it.

Car Fitment API – vehicle compatibility data for car audio & 12V parts

Q: Is this a TecDoc alternative?

No. TecDoc covers mechanical and service parts: brakes, filters, suspension. This covers 12V installation fitment: harnesses, fascias, steering-control adapters, antenna adapters, cameras and CarPlay retrofits. Different data, no overlap, and no TecDoc licence is needed to use this API.

Q: Why is there no region filter?

It would return the wrong set. Both European and North American vehicles are in the catalog, but the per-row market tagging is not reliable enough to filter on. The parameter is withheld until that is fixed.

Ask what fits a 2018 BMW 3 Series and you get brake pads

Every general fitment provider covers mechanical parts. None of them cover the box of adapters you need to actually put a head unit in a dashboard.

No TecDoc licence involved

TecDoc is brakes, filters, suspension. This is the 12V install layer next to it: harnesses, fascias, CAN-bus steering-control interfaces, antenna adapters, reverse cameras, CarPlay retrofits.

None of it comes from TecDoc, so none of it needs a TecDoc contract. Competing integrations charge $89–399 a month and expect you to bring your own licence.

Eight catalogues, one vehicle list

Metra, Connects2, PAC, Scosche, Crux, Aerpro, iDatalink and CARAV each publish application guides in their own format, spelling every model differently.

They are normalized against a single taxonomy. One query returns all of them, and you never reconcile “3 Series” against “3-Series” again.

The qualifier ships with the fitment

A 2013 Golf spans two chassis generations and the adapter differs between them. That condition arrives on every part as note: MK6, F30 F31, non-amplified only.

It decides whether a part actually works. It is also the first field a spreadsheet export throws away.

The vehicle list is free

All 47,349 rows. No key, no metering, commercial use fine. Also on GitHub as CSV, free for commercial use.

Building a Year/Make/Model dropdown should not need a contract. The part-to-vehicle links are the hard part, and those are what a key covers.

Every make, not a shortlist

139 makes carry a vehicle list you can query for free. Six of them answer fitment without a key too — those are linked below.

Toyota4,918 vehicles BMW4,670 vehicles VW3,483 vehicles MERMercedes5,015 vehicles

fORD1 vehicles

Nissan2,718 vehicles

Audi2,395 vehicles

Chevrolet2,689 vehicles

hyundai1 vehicles

Honda1,629 vehicles

Fiat1,143 vehicles

Mazda1,580 vehicles

Kia1,424 vehicles

Peugeot970 vehicles

Renault1,196 vehicles

Opel719 vehicles

Skoda694 vehicles

Seat499 vehicles

Volvo609 vehicles

Jeep973 vehicles

Porsche610 vehicles

Subaru753 vehicles

+127 moresee all

Marks identify vehicle compatibility only. No affiliation with or endorsement by any manufacturer is implied.

Reference

Four endpoints. Plain GET, JSON out, CORS open, no auth on the sandbox. Base URL https://ymmfit.com/v1.

GET

/v1/meta

no key

Catalog totals, part categories, contributing sources, and exactly what the sandbox covers. Start here.

$ curl https://ymmfit.com/v1/meta

GET

/v1/makes

no key

All 139 makes with model counts and year ranges. Complete, not limited to the sandbox.

Param	Type	Notes
q	string	Case-insensitive substring on the make name. Optional.

$ curl "https://ymmfit.com/v1/makes?q=merc"

GET

/v1/models

no key

Every model under one make, with the years each was built. The slug that comes back is what you pass as model.

Param	Type	Notes
make REQUIRED	string	Make slug from /makes, e.g. bmw.

$ curl "https://ymmfit.com/v1/models?make=bmw"

GET

/v1/parts

sandbox

Every compatible part for one vehicle, across all contributing brands.

Six makes answer without a key, from model year 2012. A make that exists in the catalog but sits outside the sandbox returns 403 outside_sandbox instead of an empty list, so restricted access never looks like missing data.

Param	Type	Notes
make REQUIRED	string	Make slug, e.g. vw.
model REQUIRED	string	Model slug from /models, e.g. golf.
year REQUIRED	integer	Four-digit model year.
category	string	Optional. Deep coverage: harness, dashkit, carplay, swc, speaker, antenna — 93% of the catalog. Thinner: camera, amp, aux. Barely populated: parking, dab, headunit — valid values, but expect empty results. Exact counts are in what’s in it.

$ curl "https://ymmfit.com/v1/parts?make=vw&model=golf&year=2013&category=swc"

{
  "vehicle": { "year": 2013, "make": "VW", "model": "Golf" },
  "count": 23,
  "parts": [
    {
      "mpn": "CAVW02",
      "brand": "Aerpro",
      "category": "swc",
      "title": "Infodapter to suit Volkswagen",
      "note": "MK7",
      "source": "aerpro"
    }
  ]
}

ERR

Errors

Every failure returns JSON carrying an error code and a message. Branch on the code.

Status	Code	Means
400	missing_parameter	A required query param is absent.
400	invalid_year	Year is not a four-digit number.
400	invalid_category	Unknown category. Valid values come back in the body.
403	outside_sandbox	The make is in the catalog; its fitment needs a key.
404	unknown_make	No such make. List them at /v1/makes.
404	unknown_vehicle	No such model under that make.
404	unknown_year	Model exists; that year is not in the sandbox. The body lists the years that are.

What’s in it

Counts below come from /v1/meta. Per-make detail is on the coverage page.

NORMALIZED FROM

PAC Scosche Crux Aerpro iDatalink CARAV

Part categories

dashkit9,613

carplay6,986

harness1,921

camera1,593

swc1,025

speaker827

antenna452

179

amp158

aux124

parking2

dab1

headunit1

Data sources

acv155,150

metra121,321

connects2112,021

carav48,239

pac41,540

carplay_stores35,833

aerpro26,084

metra_doc23,258

idatalink22,973

housebrands17,460

crux16,249

focal_inside16,036

Limits worth knowing before you build

Coverage runs deepest where the aftermarket does: mainstream European and North American models from roughly 2005 on. Pre-2000 cars, commercial vans and low-volume models are thinner.
There is no region parameter. Both EU and US vehicles are in the catalog, but per-row market tagging is not reliable enough to filter on yet, so the parameter is withheld rather than shipped returning the wrong set.
Fitment is install compatibility as published by the part manufacturer, not a guarantee against one specific factory-option combination. Where note is absent, the fitment is unconditional as published.
Some model names still carry multi-model strings from their source guides, such as Silverado/gmc Sierra. Real data, imperfectly normalized.

Get a key

The sandbox is open right now. Full-catalog keys go out by hand to the first few integrations, so the contract gets built around real use instead of guesses.

Sandbox Six makes from 2012, plus the full vehicle list. Production use fine. Free

Full catalog All 695,150 links, every make and year. from €149

Bulk export Whole dataset with scheduled refresh, for stacks that can’t call out at request time. Talk to us

Pricing is indicative and settles with the first integrations. Asking for a key doesn’t create an account or charge anything.

Store or project URL

What are you building on?

Lookups per month 10k – 50k

Anything else?

Reply from a human, usually same day.

Got it. You’ll hear back from a human, usually the same day. The sandbox stays open in the meantime, and anything you build against it keeps working.

Questions

Is this a TecDoc alternative?

No. TecDoc covers mechanical and service parts. This covers the install layer: harnesses, fascias, steering-control adapters, cameras, CarPlay retrofits. Different data, no overlap, and no TecDoc licence needed.

Do I need a key to try it?

No. The sandbox needs no signup and no card, and the vehicle taxonomy is free in production. A key only widens fitment past the six sandbox makes.

How current is the data?

The catalog runs to 2026 model years. It refreshes when manufacturers publish new application data, which happens in bursts around model launches rather than daily. Bulk customers get a changelog per refresh, so you can diff instead of re-importing.

Why is there no region filter?

It would return the wrong set. A Cadillac Escalade and a VW Golf sit side by side in the catalog, but per-row market tagging isn’t reliable enough to filter on. The parameter stays out until that’s fixed.

I use the YMMFit Shopify app. Is this different?

Same data, different shape. The Shopify app is the done-for-you version, with the storefront filter and catalog mapping set up for you. The API is for everyone not on Shopify, or building their own.

Fitment data for
car audio, as an API

Try it — no key, no signup

Ask what fits a 2018 BMW 3 Series and you get brake pads

No TecDoc licence involved

Eight catalogues, one vehicle list

The qualifier ships with the fitment

The vehicle list is free

Every make, not a shortlist

Reference

/v1/meta

/v1/makes

/v1/models

/v1/parts

Errors

What’s in it

Part categories

Data sources

Limits worth knowing before you build

Get a key

Questions

Fitment data for car audio, as an API

Try it — no key, no signup

Ask what fits a 2018 BMW 3 Series and you get brake pads

No TecDoc licence involved

Eight catalogues, one vehicle list

The qualifier ships with the fitment

The vehicle list is free

Every make, not a shortlist

Reference

/v1/meta

/v1/makes

/v1/models

/v1/parts

Errors

What’s in it

Part categories

Data sources

Limits worth knowing before you build

Get a key

Questions

Fitment data for
car audio, as an API