[BUG] Remote Control: new session from claude.ai reuses the pre-created session's conversation (deterministic v5 session id)

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?

With claude remote-control running in default mode (--spawn same-dir, --create-session-in-dir on), creating a new session from claude.ai/code against that directory does not create a new conversation. The message is appended to the pre-created session's existing conversation, and the reply is generated with that conversation's full history in context.

The mechanism appears to be that the rc-spawned session gets a deterministic (UUIDv5) session id, while every session started by hand gets a random UUIDv4. Note the version nibble (first character of the third group):

UUIDv5   48b20cc7-0eed-542d-....-............   <- rc-spawned (entrypoint: sdk-cli)
UUIDv4   a5dd9831-fe31-4a76-....-............   <- terminal session
UUIDv4   1de85060-6cc5-4b90-....-............   <- terminal session
UUIDv4   17e7f85b-07de-4f34-....-............   <- terminal session
UUIDv4   6abbc4e0-b966-4d51-....-............   <- terminal session
UUIDv4   f1e6a7fc-33f4-4743-....-............   <- terminal session

A v5 id is a hash of fixed inputs, so all remote sessions opened against a given directory appear to collapse onto one local session id, one transcript file, one conversation.

Impact is not cosmetic. Because the "new" session inherits the whole prior conversation:

• the reply is answered in the context of unrelated earlier work,
• every new remote session pays the token cost of the accumulated history on its first message,
• the single transcript grows without bound. Mine reached 9.4 MB / 4342 records over two days.

This may share a root cause with #86868 (--no-create-session-in-dir prevents session resume). Both are consistent with the bridge keying sessions by directory rather than by session identity: with the pre-created session present, new sessions collapse into it; with it absent, prior sessions fail to re-attach.

What Should Happen?

Creating a new session from claude.ai/code should start a new conversation with empty context and its own transcript file, the same as running claude in a terminal does.

Error Messages/Logs

No error is emitted. The failure is silent — the session looks new in the UI, but the model answers with prior context.

Measured before/after around a single new-session creation, counting transcripts in ~/.claude/projects/<project>/:

count before: 67 transcripts        count after: 67 transcripts
new files: none
<rc-session-uuid>.jsonl   9,364,351 -> 9,366,802 bytes  (+2,451)

The test message was appended to the existing thread, and the assistant replied with a summary of work from the previous two days rather than treating it as a fresh conversation:

2026-08-16T20:16:17  user       test 1234, ignore
2026-08-16T20:16:29  assistant  Noted - nothing to do. Standing state, unchanged: the loop is
                                stopped, no monitors running, [...]

Parsing that transcript after the new session was created still shows a single conversation:

records: 4342
roots (parentUuid=None, type=user): 1
distinct sessionId values: 1

Steps to Reproduce

1. In a directory, run claude remote-control (defaults: --spawn same-dir, --create-session-in-dir on). One session is pre-created.
2. Record the transcript files: ls ~/.claude/projects/<project-slug>/*.jsonl
3. From claude.ai/code, create a new session against that directory and send any message.
4. List the transcripts again.

Expected: a new .jsonl file. Actual: no new file; the pre-created session's .jsonl grows, and the reply carries that session's prior context.

The session id of the rc-spawned session can be read from ~/.claude/sessions/<pid>.json — it is a v5 UUID, where terminal sessions are v4.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.233

Platform

Claude subscription (Team)

Operating System

Ubuntu 26.04 LTS, Linux 7.0.0-1010-aws (x86_64)