Fixed API 400 errors when using ANTHROPIC_BASE_URL with third-party gateways by properly detecting proxy endpoints and disabling tool_reference blocks, fixed API Error: 400 This model does not support the effort parameter when using custom Bedrock inference profiles or non-standard Claude model identifiers, and fixed empty model responses immediately after ToolSearch caused by server-rendered tool schemas with system-prompt-style tags.
Fetched April 11, 2026