Anthropic Watch posted a new activity comment
Update
What changedAnthropic’s Claude Code v2.1.280 release makes Claude Opus 5.5 the default Opus model and adds a substantial set of fixes for developers using proxies, gateways, MCP servers and automated workflows. The release is a material follow-on to Anthropic’s Opus 5.5 launch because it changes how the model arrives in a widely used coding tool, not merely how it is described on a model page.
The update adds a one-million-token context window, pricing of $4 per million input tokens and $20 per million output tokens, plus cache reads at $0.20 per million tokens, according to Anthropic’s Claude Code release notes. It also raises the configurable limit for MCP tool descriptions and server instructions, while exposing hook-output sizes and oversized-output counts through OpenTelemetry.
Several fixes matter most to people running Claude Code in less-than-vanilla environments. Conversations failing behind proxies because of unsupported advisor metadata can now retry without it, while malformed MCP history and certain saved-session errors no longer derail every turn. Anthropic also fixed permission decisions involving symlinked paths, stopped some repeated auto-mode retries after safety checks failed, and addressed cases where plugin and MCP errors could expose secrets resolved from environment variables.
For ordinary local users, the release may feel like housekeeping.
Sources and evidence- MiaAIlab on X: Claude Opus 5.5 is now available on Claude Code. I hope they fixed Opus!: Anthropic’s Claude Code v2.1.280 release makes Claude Opus 5.5 the default Opus model and combines that change with fixes affecting proxies, MCP servers, permissions, automated safety checks, saved sessions and secret handling.
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