OpenAI routes its shutdown notices to the account that created the API key

The check takes one login. Sign in to platform.openai.com with the account that pays the API bill, open Usage, and switch the breakdown to group by model; the names in the last 30 days are what your code actually calls ^[13]. On Anthropic, open the Usage page in the Claude Console and click Export, which returns a CSV broken down by API key and by model, a procedure Anthropic documents for auditing deprecated models ^[14].

Failure on the day is abrupt. According to the dev.to write-up, a call to a retired model returns an error and the integration stops ^[9]. OpenAI's documentation says "software relying on OpenAI models may need occasional updates to keep working" ^[11], and the same write-up notes that Anthropic writes almost the same sentence ^[12].

Not every cutoff is the same job. On 28 September the old completion snapshots, gpt-3.5-turbo-instruct, babbage-002, davinci-002 and gpt-3.5-turbo-1106, are folded into gpt-5.6-terra, so the work is a model string and a regression pass ^[3]. On 24 September the Videos API goes along with sora-2 and sora-2-pro, and the deprecation page lists no replacement ^[2]. Runtimewire reports that the same date ends OpenAI's run as a supplier of generative video models to developers, five months after the consumer app and website closed on 26 April ^[19][20][25]. sora-2 shipped on 30 September 2025 ^[21], which gave the API 359 days of life ^[3].

Four of the published cutoffs fall inside the 29 days between 24 September and 23 October ^[1]. Twenty days of notice, which is what gpt-5.4-cyber got, works out at about a ninth of the six-month minimum, and that minimum applies to generally available models ^[8][2]. Six months is a generous notice period for an API, and it is worth nothing in an inbox nobody reads.

The softest number here is the one the routing argument rests on. The dev.to author says the retirement notice goes by email to the developer account that created the API key, and that half the time that account belongs to an agency no longer working with the client ^[10]. Half is an estimate from one practice's client base, and the piece does not say how it was counted. For it to describe your setup, your key inventory has to look like his, and the Usage view settles that in a few minutes ^[13]. Where nobody at the company can sign in at all, which the write-up calls the most common case ^[15], the remedy on the record is administrative: the provider account opened in the company's name, paid by the company, with the outside developer added as an invited user ^[17].