Last verified: 2026-08-06

Fast mode on Opus 4.7 now returns an error

A Claude Cowork error and how to fix it. The exact message, why it happens, and the steps that resolve it.

Claude Cowork

POST /v1/messages
{ "model": "claude-opus-4-7", "speed": "fast" }

→ error — fast mode removed 2026-07-24

Fix:

Move to Opus 5 or Opus 4.8, which still support fast mode, or drop the speed parameter — Opus 4.7 is still available at standard speed.

Unlike the Opus 4.6 deprecation, there is no fallback to standard speed — it fails outright · changelog

Still stuck?

See the full cross-platform troubleshooting index, the Claude Cowork hub, or the command reference. Paste your error into the search box on the index to find related fixes.