Developer API

A free, open, key-free JSON API for the Portuguese car market: estimate the import tax (ISV) and annual road tax (IUC) in one call, value a car against live comparables, and read our stock. No sign-up, fair-use per-IP rate limits.

On accuracy: the ISV/IUC figures are a maintained estimate, cross-checked against the official AT (Autoridade Tributária) simulator and the published tax tables. They are not the official AT figure and do not replace the AT simulator or a licensed despachante.

Quickstart

curl 'https://transparent.pt/api/public/isv?cc=1950&co2=130&fuel=petrol&year=2016'

# -> {"isv":{"isv":...,"table":"A"},"iuc":{"iuc":...,"category":"B"}}

Endpoints

`GET`	`/api/public/isv`	Estimate ISV (import tax) + IUC (annual road tax) in one call. Params: cc, co2, fuel, year, month, used, from_eu, vehicle_type, range_km, particulas.
`GET`	`/api/public/valuation`	Market price range from comparable Portuguese listings. Params: make, model, year, km, fuel?, gearbox?, hp?.
`GET`	`/api/public/car_refs`	Canonical make/model vocabulary. No make → brands; with make → that brand's models.
`GET`	`/api/public/cars`	Current stock. Params: site, lang, make?, fuel?, gearbox?, max_price?, limit, offset.
`GET`	`/api/public/cars/{slug}`	Full detail for one car.

Base URL https://transparent.pt/api/public. Full machine-readable description: OpenAPI 3.1 spec.

Rate limits & fair use

/isv: ~60 requests/minute per IP (burst 20).
/valuation: ~20 requests/minute per IP (it queries live market data).
Over the limit → HTTP 429 with a Retry-After header.
Calculations are deterministic and may be cached at the CDN. Need higher limits for a widget or partner integration? Ask us for a soft key — the public tier stays key-free.

Open source

The ISV/IUC calculators behind this API are open-source (MIT) — use them as a zero-dependency Python library or self-host the API: github.com/claracarspt/calcs.

Embed the calculator

Drop the ISV+IUC calculator on any website — free, no key. Keep the "Estimate by claracars.pt" link (it is rendered inside the frame and is part of the free terms).

<iframe src="https://transparent.pt/embed-isv?lang=en" id="claracars-isv" width="100%" height="480" style="border:0;max-width:420px" loading="lazy" title="ISV + IUC calculator"></iframe>
<script>addEventListener("message",function(e){if(e.origin==="https://transparent.pt"&&e.data&&e.data.claracarsIsvHeight)document.getElementById("claracars-isv").style.height=e.data.claracarsIsvHeight+"px";});</script>

SEO-native variant (JS)

The iframe above is the simplest option, but its credit link lives inside the frame, so it counts for us, not for your page. If you want the backlink to count for your domain, use the JS snippet — it renders the same calculator and places a real, crawlable "Powered by claracars.pt" link in your page's own HTML.

<div id="claracars-isv"></div>
<script src="https://transparent.pt/embed-isv.js" data-lang="en" data-target="claracars-isv" async></script>

Attribution & free-use terms

The hosted API and widget are free and key-free. In return, when you display results from the hosted API on a public page, keep a visible “Powered by claracars.pt” link to claracars.pt. The link must be:

Crawlable — a normal <a href>, not rel="nofollow"/sponsored/ugc, on a page that is not noindex or robots-blocked.
Public — on a page reachable without login, paywall or authorisation.
Visible — rendered on the page (not display:none), next to the result.

Don't want the link? Self-host the open-source calculators (MIT) — no attribution, no rate limit, no terms. The credit is only the price of using our servers. The official widget and WordPress plugin already render the credit for you, so they are compliant by default.

Estimates only — always keep the “confirm on the official AT simulator / with a despachante” note near displayed figures. Do not present the estimate as the official AT figure.

MCP server

Same data, as Model Context Protocol tools for AI assistants.

# Remote (Streamable HTTP)
https://transparent.pt/mcp

# stdio
npx -y claracars-mcp

Discovery: /.well-known/mcp.json · Source (MIT): github.com/claracarspt/mcp · More: MCP page

Try it in Postman

Import the collection and run every endpoint from your browser — no setup.

Public workspace: Clara Cars Public API on Postman

OpenAPI spec · ISV calculator · IUC calculator · MCP server · Postman