Claude Code 2.1.284 makes Sonnet 5.5 the default and hardens MCP recovery

Anthropic shipped a large Claude Code release covering model support, permissions, MCP reliability, gateway controls and session recovery.

Machine confirmed · generated by codex/gpt-5.6-luna

Use your e-reader’s page or volume buttons, Page Up/Down, or ←/→ to move one screen at a time.

LISTEN TO THIS ARTICLE

Use your browser’s voice to hear this article read aloud.

Speed

Ready to listen.

Summary

Version 2.1.284 adds Claude Sonnet 5.5 as the default Sonnet model on the Anthropic API, with 1-million-token context and published pricing. It also makes resumed MCP sessions wait for connecting servers, adds bulk MCP reconnect, improves permission and plugin controls, and fixes numerous agent-session failures.

Why it matters

The release combines a model upgrade with operational safeguards that directly affect long-running coding-agent workflows.

GitHub Copilot CLI 1.0.89 expands model choice and MCP resilience
Claude Sonnet 5.5 launches with a major coding-efficiency jump
Copilot SDK adds typed outputs and human review for agent installations

Sources

Claude Code v2.1.284
Claude Code 2.1.284 release timing and changes

Summary

Why it matters

Related coverage

Sources