[BUG] claude mcp add -e API_KEY=xxx my-server -- npx my-mcp-server fails

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?

When trying to add a local MCP via

claude mcp add -e API_KEY=xxx my-server -- npx my-mcp-server 

I get the following

Invalid environment variable format: my-server, environment variables should be added as: -e KEY1=value1 -e KEY2=value2

Just

claude mcp add my-server -- npx my-mcp-server

works fine.

The behaviour occurs in 2.1.100 and 2.1.89.

What Should Happen?

When passing environment variables via the CLI, they should be added to ~/.claude.json.

Error Messages/Logs

claude -d --verbose mcp add -e API_KEY=xxx my-server -- npx my-mcp-server 
Invalid environment variable format: my-server, environment variables should be added as: -e KEY1=value1 -e KEY2=value2

Steps to Reproduce

1. claude mcp add -e API_KEY=xxx my-server -- npx my-mcp-server

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.100

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_