Claude Code 2.1.219 Makes Claude Opus 5 the Default Opus Model
Claude Code 2.1.219 makes Claude Opus 5 the default Opus model with 1M context and fast mode at $10/$50 per Mtok, and adds a sandbox.network.strictAllowlist setting to silently deny non-allowlisted hosts.
What it is
A same-day Claude Code release tied to Anthropic's Claude Opus 5 launch, switching the CLI's default Opus model and adding a stricter network sandbox option.
What it does
Sets claude-opus-5 as the default Opus model with a 1M token context and fast mode priced at $10/$50 per million tokens, adds sandbox.network.strictAllowlist to deny non-allowlisted hosts outright instead of prompting, adds a DirectoryAdded hook that fires after /add-dir or register_repo_root, and surfaces mcp_server_errors in the headless stream-json init event for MCP configs that failed validation.
Why it matters
Unlike a prompt for every unlisted host, strictAllowlist fails closed by default, which matters if you're running Claude Code in CI or unattended agent loops where nobody is there to click approve.
How to use it
Update Claude Code to pick up claude-opus-5 automatically as the default Opus model, and set sandbox.network.strictAllowlist in your settings if you want sandboxed commands to hard-deny instead of interactively prompt on unknown hosts.
Claude Code 2.1.217 Adds Emoji Autocomplete and Fixes an MCP Memory Leak
Claude Code 2.1.217 adds emoji shortcode autocomplete, warns when transcript writes fail instead of losing sessions silently, and fixes a memory leak from truncated MCP tool outputs.
Claude Opus 5 Ships: Cheap as Sonnet, Anthropic Claims, Smart as Fable
Anthropic released Claude Opus 5, described as a thoughtful and proactive model approaching Claude Fable 5's frontier intelligence at half the price.
Claude Code 2.1.218 Moves /code-review to a Background Subagent
Claude Code 2.1.218 runs /code-review as a background subagent instead of filling the main conversation, and fixes a bug where the left arrow key discarded the conversation with no undo.