[BUG] VSCode extension session picker shows Claude Agent SDK sessions — can accidentally resume wrong session

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?

When using the Claude Code VSCode extension's session resume dropdown, sessions created by the Claude Agent SDK (running separately on the same machine) appear in the list alongside regular Claude Code sessions. There's no way to distinguish between them, so it's possible to accidentally resume an Agent SDK session in Claude Code.

What Should Happen?

Agent SDK sessions should either:

Not appear in the Claude Code VSCode extension's session picker, or
Be visually distinguishable from Claude Code sessions (e.g., labeled with their origin)

Error Messages/Logs

Steps to Reproduce

I have a Slack bot that uses the Claude Agent SDK (@anthropic-ai/sdk) to power AI agents. It runs as a separate process on the same machine (macOS) where I use the Claude Code VSCode extension.

I sent messages to my Slack bot in a notes channel. The Agent SDK processed them — calling MCP tools, doing web searches, writing to files — and responded in Slack.
Shortly after, the Claude Code VSCode extension updated. I clicked Update → Restart Extensions.
I went to resume my Claude Code session from the dropdown in the sidebar.
I unknowingly selected the Agent SDK session instead of my previous Claude Code session.
The full Agent SDK conversation appeared in the Claude Code panel — my Slack messages, all tool calls, all responses — as if it were a native Claude Code session.
Messages I then typed in the Claude Code panel continued that session seamlessly.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.76

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

macOS
Claude Code VSCode extension (latest as of March 14, 2026)
Claude Agent SDK running as a separate Node.js/Bun process in the VS Code Terminal