Anthropic releases Claude Haiku 5.5, now the default Haiku on its API

Anthropic released Claude Haiku 5.5 (claude-haiku-5-5) on October 7, 2026, and it is now the default Haiku model on the Anthropic API. It has a 1M-token context window and costs $0.10 / $0.50 per million input / output tokens, or $0.50 / $2.50 for prompts over 100K tokens.

In its announcement, "Introducing Claude Haiku 5.5", Anthropic calls it its fastest, cheapest and most capable small model yet, built for high-volume, cost-sensitive work such as summarization, subagents and browser use. That is Anthropic's own description.

Claude Code 2.1.293 shipped the same day with Haiku 5.5. Its other user-visible changes: agentType in the subagentStatusLine payload and isDeferred for $.tool.register; a fix for context compaction making Claude treat its last actions as done and redo or retract work; and the Claude Tag (Slack) channel-rules limit raised from 20 to 50 per workspace.