[BUG] --print mode generates duplicate tool_use IDs causing API error 400 #16340

Environment

• Claude CLI version: 2.0.76
• Operating System: Linux (Arch Linux 6.18.3)
• Terminal: tmux

Bug Description

When using claude --print mode with prompts that require tool usage (e.g., file reading), the CLI generates duplicate tool_use IDs, causing an API error 400.

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":"..."}

Steps to Reproduce

1. Run Claude CLI in print mode with a prompt requiring tool use:

claude --print --no-session-persistence "Read /path/to/file and summarize it"

2. The command fails with the above error

Expected Behavior

Claude should successfully read the file and return a summary.

Actual Behavior

API returns error 400 indicating tool_use IDs are not unique.

Additional Context

• Simple prompts that don't require tools work fine:

claude --print --no-session-persistence "What is 1+1?"  # Works

• The issue occurs regardless of --no-session-persistence flag
• Workaround: Using --tools "" to disable tools prevents the error, but also prevents Claude from using any tools

This appears to be a different issue from the tool_use/tool_result pairing issues in #6836 - this is specifically about duplicate ID generation.

🤖 Generated with Claude Code