[BUG] mcpServers key rejected in ~/.claude/settings.json despite additionalProperties: {} in schema

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

mcpServers key rejected in ~/.claude/settings.json despite additionalProperties: {} in schema

Actual: The field is rejected even though the JSON Schema declares "additionalProperties": {} (which implies extra fields are allowed)

What Should Happen?

Expected: Either the schema should document where MCP servers belong at user scope, or settings.json should accept mcpServers as a valid field for user-scoped configuration

Error Messages/Logs

Steps to Reproduce

1. Add "mcpServers": { ... } to ~/.claude/settings.json
2. Claude Code rejects with: Settings validation failed: Unrecognized field: mcpServers

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.76

Claude Code Version

2.1.77

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_