RSS & Atom Feed to JSON with New-Item Detection

Turn an RSS 2.0 or Atom feed — from a public URL or pasted XML — into normalized, agent-ready JSON — stable id, title, url, publishedAt — and flag which items are new compared to the IDs you already processed.

Why use it

• "What's new?" in one call — pass knownIds from your last run (top-level for URL feeds, or per pasted document); each entry gets isNew, plus newCount and duplicateCount.
• One schema for RSS and Atom — no more per-feed parsing quirks in your Make/n8n/agent workflow.
• Deduplicated & deterministic — duplicate GUIDs/links collapsed, SHA-256 per snapshot.
• Cheap — flat $0.003 per feed, ideal for frequent schedules.

Input

Field	Description
publicDataOnly	Must be true.
feedUrls[]	Public http(s) feed URLs to fetch (see Fetching from URLs).
knownIds[]	Optional, up to 5,000 previously seen entry IDs; applies to every feed in feedUrls.
documents[]	Optional pasted feeds: objects with xml (required, feed XML) and optional per-document knownIds.

Supply at least one of feedUrls or documents; 1–5 items in total per run (URLs + pasted documents).

RSS 2.0 and Atom only, 1 MiB and 500 entries per feed; each entry needs an absolute http(s) link. No RSS 1.0/RDF, DTDs or article fetching (only the feed document itself is downloaded). Full descriptions and author fields are intentionally omitted. JSON input under 8 MB, output under 1 MB per document. Fixed 256 MB memory. Each document is parsed in an isolated child process (no Apify credentials, 160 MiB memory, 15 s CPU / 20 s wall-time limits). Nothing in the input is executed.

Example input (the public Python releases feed) is prefilled in Console and in INPUT.example.json:

{"publicDataOnly": true, "feedUrls": ["https://www.python.org/downloads/feed.rss"]}

Fetching from URLs: safety and limits

The Actor downloads only what you list, from the main process; the parser still runs in an isolated, network-free child process.

• Public http/https URLs only, ports 80 and 443 only, no credentials in the URL (user:pass@).
• The hostname is resolved and every resulting address must be publicly routable. Localhost, private (10/8, 172.16/12, 192.168/16), link-local/cloud-metadata (169.254/16), CGNAT (100.64/10), multicast, reserved and IPv6 loopback/ULA/site-local addresses are refused (URL_BLOCKED). The connection is pinned to the vetted address, so DNS rebinding cannot redirect it.
• Up to 3 redirects, each hop re-validated the same way. 10 s connect timeout, 20 s total per URL. No cookies, no authentication headers, no proxies.
• Responses are capped at 1 MiB per feed (gzip transfer encoding accepted; the decompressed size is capped too, and the download is aborted once the cap is exceeded).
• Failed fetches (URL_BLOCKED, FETCH_FAILED, FETCH_TIMEOUT, TOO_LARGE, WRONG_CONTENT) are listed in OUTPUT.errors with documentIndex, the error code and the URL, and are never charged. Only successfully processed items are charged.
• documentIndex counts pasted documents first, then URL entries. Every output item has sourceUrl (null for pasted documents) and fetchedUrls; OUTPUT.fetchedUrls is the number of successful downloads in the run.
• Requests identify as ZendrenApifyActor/0.2 (+https://apify.com/zendren). Only fetch content you are permitted to process.

Output

{"documentIndex": 0, "kind": "feed", "type": "rss2", "entryCount": 10, "newCount": 7, "duplicateCount": 0,
 "sourceUrl": "https://www.python.org/downloads/feed.rss", "fetchedUrls": 1,
 "entries": [{"id": "https://www.python.org/downloads/release/python-3150/", "title": "Python 3.15.0",
   "url": "https://www.python.org/downloads/release/python-3150/", "publishedAt": "Fri, 09 Oct 2026 13:54:59 +0000", "isNew": true}],
 "sha256": "483235f5…"}

The key-value store record OUTPUT summarises the run: processed and fetchedUrls counts, an errors list (with documentIndex, error code, message and, for URL items, the url) and stoppedForSpendingLimit. Invalid documents are reported there, are not written to the dataset and are not charged; valid siblings still process. Check OUTPUT even when the run status is Succeeded.

Pricing

Pay per event, no subscription, no platform-usage pass-through:

Event	Price	When
processed-document	$0.003	One feed successfully processed and saved to the dataset
apify-actor-start	$0.00005	Once per run (Apify synthetic start event)

Example: 5 documents in one run = $0.01505. Invalid documents are free; the start event still applies to runs whose input is rejected. Set Maximum cost per run in Console or ?maxTotalChargeUsd= in the API — the Actor stops before parsing a document it cannot pay for.

Use it from the API, Make, n8n or an AI agent

curl -X POST "https://api.apify.com/v2/acts/zendren~feed-snapshot-delta/run-sync-get-dataset-items?maxTotalChargeUsd=0.05" \
  -H "Authorization: Bearer $APIFY_TOKEN" -H "Content-Type: application/json" \
  -d @INPUT.example.json

Send the token in the Authorization header, never in the URL. The Actor is also usable as an MCP tool through Apify's MCP server (mcp.apify.com).

Responsible use

Supply only public data you are permitted to process, with no personal data. publicDataOnly is a policy acknowledgement, not an automated privacy detector. The Actor only downloads the exact public URLs you list (no crawling, no logins, no proxies) and never calls external AI services.

Support

Found a bug or need a format supported? Open an issue on the Actor's Issues tab. Fixture attributions: see NOTICE.md in the source.