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Convert a URL to PDF in Python with httpx

The baseline job: give the API a URL, get PDF bytes back. One POST, binary response, no callback dance — the body of the response is the file. Everything else on this page is about doing that reliably: auth, error handling, and not treating a JSON error as a PDF.

Below is a complete, runnable Python program using httpx (pip install httpx). It reads your API key from the SNAPDOK_KEY environment variable — free keys take about thirty seconds and need no card.

import os
import httpx

resp = httpx.post(
    "https://snapdok.io/v1/render",
    headers={"Authorization": "Bearer " + os.environ["SNAPDOK_KEY"]},
    json={
        "url": "https://your-app.com/report/42",
        "format": "pdf",
    },
    timeout=90,
)
resp.raise_for_status()

with open("page.pdf", "wb") as f:
    f.write(resp.content)

The response is the document itself with Content-Type: application/pdf. Errors come back as JSON with an error code — which is why every sample here checks the status before writing bytes to disk: the classic integration bug in every language is saving {"error":"UNAUTHORIZED"...} as report.pdf and discovering it a week later.

PDF rendering uses the page's print stylesheet and reflows to paper width, so the width parameter does not apply to PDFs (it is a screenshot concept). If a page looks wrong as PDF, its @media print CSS is usually the culprit. Repeated identical requests inside 24 hours are served from cache — X-Cache: HIT — and not charged.

Same endpoint, one more trick: if the page you are rendering has a form on it, adding "pdf_forms": true to a PDF render brings it back with real, fillable AcroForm fields — a PDF people can type into, not a picture of one. How that works.

Notes for httpx

httpx looks like requests but differs where it bites: it ships a 5-second default timeout, which a render that drives a real browser will blow through on heavier pages — hence the explicit timeout=90. raise_for_status() exists and behaves the same. If you are on asyncio already, the same call works with httpx.AsyncClient and await client.post(...) — the request body and headers are identical.

Response headers worth reading

HeaderMeaning
X-CacheHIT = served from the 24h cache, free.
X-RateLimit-RemainingRequests left in the current second.

Full parameter reference: the docs. Hard numbers on caps and timeouts: limits.

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