Anthropic released Claude Code version 2.1.274, introducing new visibility into system resource usage and significant updates to the Model Context Protocol (MCP) client behavior.
- Added a visible warning when memory usage is critical, providing steps to free memory or restart safely.
- Introduced the CLAUDE_CODE_MCP_STARTUP_WAIT_MS environment variable to bound the wait time for connecting MCP servers during the first non-interactive turn.
- Changed Bedrock, Vertex, Foundry, and telemetry-disabled installs to use the v2 MCP client and MCP 2026-07-28 negotiation with direct HTTP servers by default.
- Fixed sessions getting stuck in retry loops due to corrupted transcripts and resolved issues with MCP tool calls timing out or refusing connections incorrectly.
- Improved Claude apps gateway boot reliability by retrying Postgres connections and optimizing spend-limit checks under load.
These changes enhance system stability, improve debugging capabilities for configuration and connection issues, and ensure more robust handling of external server protocols.