https://modelsatwork.news/article/anthropic-claude-platform-notes-opus-4-8-fast-mode-removed-30-nov-ip-allowlist-message-threads Models at Worken 2026-11-09T17:20:00.000Z Anthropic ends Opus 4.8 fast mode on 30 Nov; adds IP allowlist beta Anthropic, Claude, API, Cost, Security