Claude Code 2.1.220 Defaultly Switches to Opus 5, Nested Subagent Depth Expanded to 3 Layers
On July 24, 2026, Anthropic released the 2.1.220 series updates for Claude Code: version 2.1.219 switched the default model to Claude Opus 5 (1M context window), and expanded the default nested subagent depth from 1 to 3; version 2.1.218 changed `/code-review` to run as a background subagent. An early August evaluation showed that the gap between Opus 5 and GPT-5.6-Sol on Terminal-Bench 2.1 was less than 0.5 percentage points, and the competition for AI programming agents has shifted to focusing on both models and orchestration layers. This article sorts out the version changes based on the official CHANGELOG, and provides configuration instructions for subagent depth limits, concurrency upper limits and other parameters.
Read MoreVS Code 1.131: At a Glance of Subagent Running Status, Built-in Voice Input and Hybrid Markdown Editor
On July 29, 2026, VS Code 1.131 was released: the Agents window now allows real-time viewing of the models used by Subagents, their running duration, and current tool calls; built-in experimental dictation is now available across Chat, the editor and the terminal; a mixed Markdown editor has been added to the Agents window, supporting in-place editing and executable annotations for Agents. Combined with the Agent Host, Git Worktree and review optimizations introduced in version 1.130, this article sorts out the context and activation methods of the Agent infrastructure updates in July.
Read MoreClaude Opus 5 Released: 1M-Context Window Becomes Default Flagship Model of Claude Code
On July 24, 2026, Anthropic released Claude Opus 5, which features native 1 million-token context window, default thinking mode, and the same pricing as Opus 4.8. For Claude Code v2.1.219 and above, accounts such as Max/API will parse "Default" as Opus 5, while the default setting for Pro tier remains Sonnet 5. This article sorts out the specifications of Opus 5, Fast Mode and Effort levels, as well as the toolchain updates of Claude Code in July including Subagent background running, nested delegation, /code-review background review and /doctor self-check, and provides step-by-step guides for version checking and model switching.
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