[BUG] Remote Control sessions need auto-compaction to prevent duplicate tool_use ID crash

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?

Remote Control sessions are particularly susceptible to the duplicate tool_use ID error (messages.N.content.1: tool_use ids must be unique) because they encourage long-running, often unattended sessions. Once this error occurs, the session is unrecoverable — every retry hits the same 400 error in a loop, and the user must abandon the session entirely.
The problem:

Remote Control's core use case is kicking off long tasks and monitoring from another device
Long conversations eventually trigger duplicate tool_use IDs in the message history
The API rejects these with a 400 error that loops infinitely
/compact exists but requires manual invocation — easy to forget, especially when working from a phone
There is no auto-recovery or way to salvage the session

What Should Happen?

Requested fix (any of these would help):

Auto-compact — automatically compress conversation history when approaching a message/token threshold, especially in Remote Control mode
Fix duplicate ID generation — ensure tool_use IDs are always unique regardless of conversation length
Auto-recovery — if a duplicate ID error is detected, automatically compact/truncate the history and retry instead of looping
Warning — at minimum, warn the user when the conversation is getting long and suggest running /compact

Environment:
macOS
Claude Code latest
Remote Control session via claude.ai/code

Error Messages/Logs

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.183.content.1: tool_use ids must be unique"},"request_id":"req_011CYbxH8hQvMT4PgFEK45AJ"}


API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.183.content.1: tool_use ids must be unique"},"request_id":"req_011CYbxH9eDRswAVybwCaviQ"}


API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.183.content.1: tool_use ids must be unique"},"request_id":"req_011CYbxHAUKuPmnDDXDjwANv"}


API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.183.content.1: tool_use ids must be unique"},"request_id":"req_011CYbxHBPdsUNcqDPbjwFuG"}


API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.183.content.1: tool_use ids must be unique"},"request_id":"req_011CYbxHCDzP8WQ6aT5CW3gU"}

Steps to Reproduce

Start claude remote-control
Connect from phone/browser and work through a long session (~100+ messages with many tool calls)
Eventually a tool call generates a duplicate ID
Session enters an unrecoverable 400 error loop
User input (e.g., typing "yes") also fails with the same error

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.63 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_