Claude Platform release notes — November 12, 2026

The Claude Platform release notes list changes to the Claude API, client SDKs, and Claude Console, newest first, with entries from September 1 through October 29, 2026. Recent items include the beta Usage and Cost Analytics API, a raised 128 MB maximum request size for the Messages and Token Counting APIs, the beta Claude Tag API for Claude Enterprise, Claude Models on Google Cloud (Anthropic managed), and API version 2026-10-21 with new SDK and CLI releases. Earlier entries cover the launches of Claude Opus 5.5, Claude Sonnet 5.5, Claude Haiku 5.5, and Claude Fable 5.1, along with user profiles, organization webhooks, and OpenTelemetry export.