Claude outage reports surged on Sunday evening as Claude AI hit API 529 "Overloaded" errors that disrupted coding tasks and Claude Code. Downdetector said the reports began coming in around 8:30 p.m. EDT, and they topped more than 4,000 by 8:45 p.m. EDT.
Claude Code and chat service
Users said the failures were not limited to one workflow. Downdetector reported problems with both Claude Code and Claude's chat service, which means the same overloaded API layer was catching people trying to code and people simply trying to get a response.
One user wrote, "Started 5 min ago: Claude Code Opus 4.8 getting API errors -- status 529 overloaded." Another said, "Taking longer than usual. Trying again shortly (attempt 4) great its been doing this for a while."
Browser access split from desktop app
One report pointed to a split in behavior across access methods. The user wrote, "Try working on the desktop app. That's working just fine. I'm running multiple projects: one in the desktop app and two in different browsers. The browser ones are down, but the desktop app is working for me so far."
That suggests the outage was not hitting every Claude access path equally. For anyone trying to keep work moving, the practical test was simple: if the browser stalled, the desktop app was worth trying before giving up on the session.
No statement from Claude
Claude had not issued a statement addressing the outage reports by Sunday evening. One post on X said, "Claude Code keeps throwing API errors and retrying. Is it down for everyone or am I the only one getting brewed?"
Another user wrote, "Due to unexpected capacity constraints, Claude is unable to respond to your message. Please try again soon." The open question is what caused the API 529 overloaded errors and when full service would return.
