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Claude Code in Early October 2026: Haiku 5.5 Default, MCP 2026-07-28, Retry Controls and More

A roundup of Claude Code releases from 2.1.287 to 2.1.295 (1–8 October 2026): Haiku 5.5 as the default Haiku model, the new MCP protocol by default for stdio servers, 529 retry tuning, plugin install from a marketplace in one command, an effort setting for subagents, 1M context defaults on cloud providers, and fixes worth updating for.

Claude Code shipped nine releases in the first eight days of October 2026. Beyond mods and the hook changes (covered separately), here's what's useful.

Run claude update to get them. (How to Update Claude Code)

Models

  • Haiku 5.5 is the default Haiku model on the Anthropic API (2.1.293). That's what the haiku alias, background tasks and /goal evaluation use. (Claude Haiku 5.5 Released)
  • 1M context by default for Opus 4.7+ and Fable on Bedrock, Google Cloud, Foundry and the Claude apps gateway (2.1.287). CLAUDE_CODE_DISABLE_1M_CONTEXT=1 keeps 200K.
  • /model's Max effort pick now applies to the current session only (2.1.290). (Effort Levels and Ultrathink)

Reliability

  • CLAUDE_CODE_OVERLOADED_RETRY_BASE_DELAY_MS (2.1.292) starts 529 backoff at a longer delay, so busy-period runs spread retries out. (Claude Code 529 Overloaded)
  • NO_PROXY is now honoured for API requests (2.1.292).
  • Regressions that could drop permission-prompt answers in cloud sessions and lose the last messages on quit were fixed (2.1.291).

MCP

  • Local stdio servers negotiate the 2026-07-28 protocol by default (2.1.292). If an older server stops working, set MCP_PROTOCOL_NEGOTIATION=legacy. (MCP Spec 2026-07-28)
  • alwaysLoad: false on an MCP server defers all its tools behind tool search (2.1.287), saving context. (Connecting MCP Servers)

Plugins and agents

  • claude plugin install --marketplace <source> adds the marketplace if needed and installs in one step (2.1.292). (Claude Code Plugins)
  • The Agent tool accepts an effort parameter, so subagents can run at a different effort level from the main session (2.1.292). (Claude Code Subagents)
  • claude attach and claude logs accept partial session names; agent view gained Ctrl+F search (2.1.288–2.1.290). (Background Sessions and Agent View)

Sessions and scheduling

Security-relevant changes

  • CLAUDE_CODE_DISABLE_ATTACHMENTS can no longer be set from a repository's .claude/settings.json, and project settings can't enable Claude in Chrome (2.1.290) — closing ways a cloned repo could change your session's behaviour.
  • /code-review gained --max-findings <n>|all (2.1.288).

Source: Claude Code changelog

EasySpawn keeps Claude Code updated on a persistent server, with your sessions, plugins and projects carried forward through every release. See how it works or join the waitlist.

Related: Claude Code Mods · Claude Code Hooks Can Now Fail Closed · Claude Code Troubleshooting · Claude Code Settings Explained

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