API Error 400: tool_use ids must be unique in --print mode (v2.1.19)

Description

When using --print mode with --output-format stream-json in Claude Code CLI v2.1.19, an API error occurs after tool execution (e.g., WebSearch).

Error Message

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.1.content.1: `tool_use` ids must be unique"},"request_id":"req_..."}

Steps to Reproduce

1. Install Claude Code CLI v2.1.19
2. Run a command that uses tools (e.g., WebSearch):

``bash
echo "/lookup-term CORS" | claude --print --output-format stream-json --verbose --allowedTools "WebSearch,WebFetch" --permission-mode bypassPermissions
``

1. The first tool call (WebSearch) succeeds
2. After the tool result is returned, the next API request fails with the above error

Expected Behavior

The command should complete successfully without API errors.

Actual Behavior

After a tool is used (e.g., WebSearch), the subsequent API request fails with tool_use ids must be unique error.

Workaround

Downgrade to v2.1.18:

npm install -g @anthropic-ai/claude-code@2.1.18

Environment

• Claude Code CLI: v2.1.19
• OS: Windows 11
• Node.js: v20+

Notes

• Interactive mode works fine (no error)
• --print mode with both stream-json and json output formats cause this error
• v2.1.18 does NOT have this issue