Claude Code v2.1.145 ships managed-agent MCP tunnels, OTEL agent tracing, JSON sessions

This is the most enterprise-flavored Claude Code release to date. The headline new capabilities — MCP tunnels and self-hosted sandboxes for Managed Agents, both in Research Preview — directly address the two largest enterprise blockers for agent deployment: connecting agents into private networks without exposing internal services, and running tool execution inside customer-controlled sandboxes rather than Anthropic-hosted ones.

Mechanically, MCP tunnels let a Managed Agent reach internal MCP servers over an authenticated reverse tunnel — no inbound firewall holes, no VPC peering required. Self-hosted sandboxes let regulated customers swap Anthropic's default execution environment for their own (think: Kubernetes namespace, on-prem container runtime) while keeping the agent control plane managed. Together these features let enterprises run agents against their own data and tools without copying anything to Anthropic.

The v2.1.145 release notes add the developer-facing plumbing: `claude agents --json` exposes live sessions for scripting and dashboards, OTEL spans now carry agent_id and parent_agent_id with corrected trace parenting (a long-standing complaint), and the status-line JSON input now surfaces GitHub repo and PR context. Anthropic also improved background session handling, model/plugin management, and MCP/SDK cold-start times.

Competitive read: Google's Antigravity Managed Agents launched the same week with overlapping pitch. Anthropic's advantage is that Claude Code already has the developer mindshare — Boris Cherny's "Code with Claude London" event drew strong engagement on X, and r/Anthropic continues to be one of the most active vendor-specific dev subs. The risk: Reddit complaints that Claude 4.7 feels "cost-saving" vs 4.6 (154 upvotes, 83 comments) suggest some perceived quality regressions Anthropic needs to address before piling on more enterprise complexity.