Claude Code 2.1.81 adds --bare mode and channels permission relay

• Anthropic shipped Claude Code 2.1.81 with a new release thread --bare flag for scripted -p calls, and the changelog thread says it skips hooks, LSP, plugin sync, and skill directory walks for faster, more deterministic automation.
• The same release adds a changelog thread --channels permission relay so channel servers with the right capability can forward tool approval prompts to your phone.
• Claude Code’s prompt update system prompts now enforce “no memory” requests more strictly and tell the Read tool to prefer targeted section reads over whole-file reads when the relevant region is already known.
• The release thread bundles a long reliability pass too, including fixes for repeated re-auth in concurrent sessions, proxy 400 errors tied to structured-outputs headers, hanging background-agent output, and a Node.js 18 crash.

The headline change is --bare, which Anthropic describes in the changelog thread as a mode for scripted -p calls that skips hooks, LSP startup, plugin sync, and skill directory walks. That makes the CLI behave more like a stripped-down automation runtime than an interactive coding environment. The same note says --bare requires ANTHROPIC_API_KEY or an apiKeyHelper passed via settings, with OAuth and keychain auth disabled and “auto-memory fully disabled.”

That combination matters because it narrows side effects during non-interactive runs. In the same release family, the tracked CLI surface in surface diff also shows a new critique command, a new MCP_OAUTH_CLIENT_METADATA_URL environment variable, and new config keys including showClearContextOnPlanAccept.

The second feature is --channels permission relay. Anthropic’s changelog thread says channel servers that declare the permission capability can send tool approval prompts to a phone, extending the approval loop outside the terminal.

The system prompt changes are small but operationally relevant. According to the prompt update, memory access triggers are now consolidated to cases where prior work is relevant, and there is a hard rule that if a user asks Claude to ignore memory, it must “not cite, compare against, or mention memory” and should answer as if none exists. The same update also switches Read-tool guidance from whole-file reads toward targeted reads of known sections, especially for large files.

The rest of 2.1.81 is mostly bug fixing. Anthropic says it fixed repeated re-authentication when multiple Claude Code sessions were open, voice-mode failures that surfaced as a generic “check your network” message, and a bug where the structured-outputs beta header could trigger 400 errors on proxy gateways forwarding to Vertex or Bedrock changelog thread. The release also fixes a race where background agent task output could hang indefinitely, restores Bash PATH inheritance on Windows with Git Bash in VS Code, and adds MCP OAuth support for Client ID Metadata Document (CIMD / SEP-991) for servers without dynamic client registration release thread.