Claude Code v2.1.267 caps effort per provider and fixes prompt-cache stability
Anthropic
Claude Code v2.1.267 (Sept 9) adds a maxEffortLevel setting that caps effort level per provider including Bedrock, Vertex and Foundry, plus a --system-prompt-snapshot off flag and a batch of prompt-cache stability fixes for mid-session MCP/plugin tools, /model switches and resumed sessions. It also patches a security bug where backslash marketplace paths bypassed containment on macOS/Linux. This continues the Sept 8 v2.1.265/.266 pair covered yesterday.
Why it matters
maxEffortLevel gives enterprises cost control on BYOK providers, and the containment fix is a real security patch worth upgrading for.
Importance: 2/5
Continuation of the 2.1.265/266 series; includes a security fix