API Error: 400 invalid params - chat content has invalid message role: system (2013) in Claude Code CLI v2.1.156 using Minimax Anthropic API

[ZoanHy]

Description

I am currently using Claude Code CLI v2.1.156 with the following Anthropic-compatible API endpoint:

https://api.minimax.io/anthropic

Because I am not located in China, I use this endpoint instead of the default one.

Starting today, every chat request fails with the following error:

API Error: 400 invalid params, chat content has invalid message role: system (2013)

Steps to Reproduce

1. Open Claude Code CLI v2.1.156
2. Configure API endpoint to:
   https://api.minimax.io/anthropic
3. Start a normal chat session
4. Send any prompt
5. Error appears immediately

Expected Behavior

Chat requests should work normally with Anthropic-compatible APIs.

Actual Behavior

All requests fail with:

API Error: 400 invalid params, chat content has invalid message role: system (2013)

Environment

• Claude Code CLI version: v2.1.156
• API provider: Minimax
• API endpoint: https://api.minimax.io/anthropic
• OS: Windows
• Issue started occurring: Today

Please help check whether:

• Claude Code CLI recently changed the message format
• system role handling became incompatible
• or Minimax Anthropic compatibility has changed recently

[RyanLee-Dev]

153 version still work.
Thanks.And we will fix today.