Claude Code v2.1.224 Adds Self-Hosted Runners, Cross-Session Messaging

Anthropic released Claude Code v2.1.224, a feature-packed update that introduces self-hosted environments, cross-session messaging, and a new plugin source, along with a heap of fixes for sandbox and remote-control issues.

Key Additions

• Self-Hosted Runners: The new claude self-hosted-runner command turns your own machines or containers into a place where Claude Code web, mobile, and desktop sessions can run. Available on Team and Enterprise plans.
• Archive Plugin Source: You can now install plugins from a zip over HTTPS without needing git or npm. Optional SHA-256 pinning is supported for security.
• Cross-Session Messaging: Claude Code sessions can now message each other across machines (macOS and Linux) with SendMessage, and you can use ListAgents to discover available sessions.
• Bedrock Region Prefix: New ANTHROPIC_BEDROCK_REGION_PREFIX env var lets you prefer a specific cross-region inference profile over the one derived from AWS_REGION.

Beefed-Up Sandbox Credential Masking

The sandbox now supports more credential-masking options:

• extract and onExtractNoMatch for structured env values
• decode: "jwt" with maskClaims for JWT-aware masking
• awsPairs / sigv4 for AWS SigV4 re-signing

These options require network.tlsTerminate and are honored only from user, managed, or --settings settings.

Notable Fixes

• Fixed long (>200 char) project paths resolving to another project's session directory – session list, rename, fork, delete, and /resume no longer cross projects.
• Fixed sandbox filesystem deny entries with trailing slashes (e.g., denyRead: "~/.aws/") being bypassed on Linux and macOS.
• Sandbox violation details now appear in Bash tool results, so Claude sees which file or network access was denied and why.
• Fixed SendMessage reporting success when writes to a teammate's inbox actually failed.
• Removed the 200-subagent-per-session spawn cap – long-running sessions no longer refuse new agents (concurrency and depth limits still apply).
• Remote Control now shows compaction progress and connection failures persistently instead of silent pauses or 8-second toasts.

Who It's For

If you're running Claude Code in production, on remote servers, or in a multi-session workflow, this release adds meaningful flexibility and plugs several security holes.