Bug in watch-mode scrapers could bill buyers twice for already-delivered data rows

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A software bug was discovered in watch-mode data scraping Actors that caused previously delivered and paid-for data rows to be re-delivered and potentially re-billed to buyers. The flaw stemmed from a capped baseline system that silently evicted older record IDs when full, causing the next polling run to treat those IDs as new. High-volume sources where a single run could return more IDs than the cap allowed were especially vulnerable, and the issue was confirmed across at least 22 different Actors including scrapers for Google Play reviews, clinical trials, and FDA recalls. The bug was particularly difficult to detect because affected runs appeared completely normal and successful, with the billing discrepancy only surfacing later in invoices. A fix has been deployed that tracks and surfaces eviction events through log warnings, status messages, run summaries, and webhook notifications, though full prevention of re-delivery requires a more substantial architectural change.

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