{"id":6180,"date":"2026-10-20T04:24:16","date_gmt":"2026-10-20T07:24:16","guid":{"rendered":"https:\/\/tucumandevelopers.com\/index.php\/2026\/10\/20\/two-tools-built-on-our-data-and-what-our-docs-left-out\/"},"modified":"2026-10-20T04:24:16","modified_gmt":"2026-10-20T07:24:16","slug":"two-tools-built-on-our-data-and-what-our-docs-left-out","status":"publish","type":"post","link":"https:\/\/tucumandevelopers.com\/index.php\/2026\/10\/20\/two-tools-built-on-our-data-and-what-our-docs-left-out\/","title":{"rendered":"Two tools built on our data, and what our docs left out"},"content":{"rendered":"
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Products with no monthly price.<\/strong> billing_cycles<\/code> lists only the terms a product is sold on. Seven products, all of them special offers, have no monthly<\/code> key at all. PulseWatch showed a dash for them and recorded no price history, so their price moves were invisible.<\/p>\n

Two prices for one product.<\/strong> PulseWatch also compares the feed with the storefront once a day, and for some products the store’s “Starting from” price was higher than the feed’s price. Its README put that down to “a stale monthly price in the feed”. The real reason is that the store adds the cheapest of a product’s required options to its “Starting from” price, while the feed publishes the base price. Both are correct. They answer different questions.<\/p>\n

None of these is a bug on either side. Each one is a field whose meaning lived in our code and nowhere else. The product-feed items on this list are now written down on the feeds page<\/a>.<\/p>\n

<\/a> How to poll a host’s feed politely <\/h2>\n

PulseWatch fetches the catalog every five minutes. Our product feed is rebuilt every 15 minutes, so two of every three fetches download a file that has not changed. That costs the client and the server bandwidth for nothing, and it is fixable with headers that are already there.<\/p>\n

Pulsed Media’s feed responses carry ETag<\/code> and Last-Modified<\/code>. Send them back and you get an empty 304 Not Modified<\/code> when nothing changed: <\/p>\n

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url<\/span>=<\/span>https:\/\/pulsedmedia.com\/data\/v1\/products.json etag<\/span>=<\/span>$(<\/span>curl -sI<\/span> \"<\/span>$url<\/span>\"<\/span> | awk<\/span> -F<\/span>': '<\/span> 'tolower($1)==\"etag\"{print $2}'<\/span> | tr<\/span> -d<\/span> '\\r'<\/span>)<\/span> curl -s<\/span> -o<\/span> \/dev\/null -w<\/span> '%{http_code}\\n'<\/span> -H<\/span> \"If-None-Match: <\/span>$etag<\/span>\"<\/span> \"<\/span>$url<\/span>\"<\/span> # 304<\/span> <\/code><\/pre>\n
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In a Python client the same thing takes a few lines with the standard library: <\/p>\n
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import<\/span> json<\/span>,<\/span> urllib<\/span>.<\/span>request<\/span>,<\/span> urllib<\/span>.<\/span>error<\/span> def<\/span> fetch<\/span>(<\/span>url<\/span>,<\/span> cache<\/span>):<\/span> req<\/span> =<\/span> urllib<\/span>.<\/span>request<\/span>.<\/span>Request<\/span>(<\/span>url<\/span>)<\/span> if<\/span> cache<\/span>.<\/span>get<\/span>(<\/span>\"<\/span>etag<\/span>\"<\/span>):<\/span> req<\/span>.<\/span>add_header<\/span>(<\/span>\"<\/span>If-None-Match<\/span>\"<\/span>,<\/span> cache<\/span>[<\/span>\"<\/span>etag<\/span>\"<\/span>])<\/span> try<\/span>:<\/span> with<\/span> urllib<\/span>.<\/span>request<\/span>.<\/span>urlopen<\/span>(<\/span>req<\/span>,<\/span> timeout<\/span>=<\/span>30<\/span>)<\/span> as<\/span> r<\/span>:<\/span> cache<\/span>.<\/span>update<\/span>(<\/span>etag<\/span>=<\/span>r<\/span>.<\/span>headers<\/span>.<\/span>get<\/span>(<\/span>\"<\/span>ETag<\/span>\"<\/span>),<\/span> body<\/span>=<\/span>r<\/span>.<\/span>read<\/span>())<\/span> except<\/span> urllib<\/span>.<\/span>error<\/span>.<\/span>HTTPError<\/span> as<\/span> e<\/span>:<\/span> if<\/span> e<\/span>.<\/span>code<\/span> !=<\/span> 304<\/span>:<\/span> raise<\/span> return<\/span> json<\/span>.<\/span>loads<\/span>(<\/span>cache<\/span>[<\/span>\"<\/span>body<\/span>\"<\/span>])<\/span> <\/code><\/pre>\n
\n<\/p><\/div>\n<\/p><\/div>\n
Three more habits that hold for any host’s feed, not just ours:<\/p>\n
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  1.  Check the timestamp, not just the status code.<\/strong> Our feeds carry generated_at<\/code>. A 200 with a feed that is three hours old means the generator stopped, and a monitor should say “stale” instead of reporting old stock as current. The same goes for a cached copy you fall back to when a fetch fails.<\/li>\n
  2.  Poll at the rebuild rate, not faster.<\/strong> If the docs say the data refreshes every 15 minutes, a five-minute poll with conditional requests is fine and a one-minute poll without them is noise.<\/li>\n
  3.  Treat unknown fields as unknown.<\/strong> When a value looks odd, like a negative stock, ask or read the docs before you give it a meaning. A guess shown on a public page becomes a fact for whoever reads it.<\/li>\n<\/ol>\n
    One store-specific tip, because PulseWatch sends visitors to our store with a referral id: our aff.php?aff=ID&pid=N<\/code> link sets the referral and then lands on that product’s order form, so a referral link can go straight to the product. A plain ?aff=<\/code> added to a store page does nothing.<\/p>\n
      <\/a> Local tools, public tunnels <\/h2>\n
    PulseWatch can publish itself on a Cloudflare quick tunnel, so the dashboard you run on a home server gets a public HTTPS address in one command. That is convenient, and it changes what the code has to defend against. A page that only you open on 127.0.0.1 now faces anyone who finds the address, and even on 127.0.0.1, a web page open in your browser may be able to send it requests.<\/p>\n
    Two defects came from that shift, and both are common in small self-hosted tools:<\/p>\n