Anthropic Releases Claude Code v2.1.311 with Self-Hosted Runner Flags and Auto-Compaction Fixes

Self-Hosted Runner Controls#

The update introduces two new parameters for self-hosted-runner: --hold-idle-file and --max-hold-min. These settings allow idle runner sessions to remain active while host systems complete processes spawned during execution.

Token Management and File State#

• Context Compaction: Standard-context sessions that cross the 200K token threshold previously failed with an error stating that usage credits were required for a 1M context. Claude Code now automatically compacts conversation history and continues execution.
• Memory Refresh Fixes: Fixed an issue where Claude read stale MEMORY.md and CLAUDE.md content following auto-compaction if those files had been modified earlier in the session.
• Startup Freezes: Solved extended freezes occurring during session launch or file reads when CLAUDE.md contained excessively long list items.

Subagents and MCP Integration#

• Late-Connecting MCP Servers: Subagents can now access Model Context Protocol (MCP) tools from servers that finish initializing after the subagent has already started.
• Hook Execution Frequency: Fixed SubagentStop hooks firing roughly twice per minute per active subagent; hooks now execute once upon completion.
• Isolated Worktree Retention: Fixed an issue where a parent subagent’s isolated Git worktree was deleted while a spawned background subagent was still actively working inside it.
• Path Configuration: Relative Model Context Protocol commands (claude mcp add, claude mcp remove, and /mcp) executed inside subdirectories now correctly record the repository root entry in ~/.claude.json instead of local folder paths. Duplicate error prefixes like ENOENT: ENOENT: in claude mcp list and get outputs have also been resolved.

Tool Performance and Network Timeouts#

• Large File Edits: Resolved up to 5-second stalls in the Write and Edit tools when modifying thousands of lines. These tools previously reported 0 lines changed upon completion.
• Cloud Session Timeouts: In Cowork cloud sessions, WebFetch and WebSearch calls no longer hang indefinitely on stalled remote connections; requests now time out after 300 seconds.
• Interruption Responsiveness: Interrupting an operation now takes effect immediately during pending MCP resource reads or background skill downloads, rather than waiting for network timeouts.
• File Ignore Rules: The @ file selector now correctly respects inclusion negations (such as !file) defined in .ignore and .rgignore files.

CLI and Daemon Diagnostics#

• Daemon Management: The CLI now directs users to run claude daemon stop --any to stop background services, replacing references to the deprecated claude daemon restart command.
• Environment Diagnostics: Corrected inaccurate shell reporting in the environment block (for example, reporting fish when the Bash tool executes commands via zsh).
• Respawn Checks: Running claude respawn <id> now checks whether the target background session ID exists before initializing the background service.