On Thursday, the developer APIs of ChatGPT, Sora, and OpenAI experienced an outage that lasted for up to an hour. OpenAI said it experienced a major outage beginning at 11 a.m. PT, and as of the time of publication, around 12:40 p.m. PT, the services appeared to still be down.

Frequent users of ChatGPT may remember that the service experienced an outage earlier this month. Most users received error messages when trying to access ChatGPT and Sora on Thursday afternoon.

OpenAI said on its status page that the major outage was caused by one of its upstream vendors, but did not provide further details. The company said it was working to fix the issue but did not say when services would be back up and running.

This is the second time in December that OpenAI's series of services have failed. When the outage occurred two weeks ago, OpenAI blamed a problem with a new telemetry service. Typically, this outage only lasts an hour or two.

Popular services that use OpenAI API, such as Perplexity and Siri's Apple Intelligence integration, don't appear to be affected by the outage, according to the companies' respective status pages and TechCrunch's testing.