Anthropic released Claude Code v2.1.277, introducing support for the AGENTS.md file as a fallback for project instructions and adding several configuration options for the Claude apps gateway.
- Added AGENTS.md support: in projects without CLAUDE.md, Claude Code reads AGENTS.md instead.
- Added CLAUDE_GATEWAY_PROXY_IS_EGRESS_BOUNDARY=1 to handle forward proxies by passing hostnames directly.
- Added optional headers map on Claude apps gateway upstreams for static header injection.
- Fixed claude -p and Agent SDK sessions hanging after internal errors, now reporting the error and exiting with code 1.
- Fixed conversations failing with "text content blocks must be non-empty" when earlier turns contained empty text blocks.
- Fixed Grep and Glob returning no matches on resource exhaustion, now returning an appropriate error.
- Improved session start-up for SDK and headless use by removing the wait for per-directory CLAUDE.md lookup.
This update provides better configuration flexibility for gateway setups and resolves critical stability issues with session management and tool execution.