Desktop app has no 1M-context Opus 5; `opus[1m]` resolves but reports "Unsupported model"

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?

nvironment

• Claude desktop app 2.2553.1, macOS (Apple silicon), Code tab
• Claude Code VS Code extension 2.1.278, and the CLI, on the same machine and account
• Plan: Max (5x)

What happens

• In the desktop app the model picker lists Opus 5, Fable 5.1, Sonnet 5, Haiku 4.5,

and under "More models" Fable 5, Opus 4.8, Opus 4.7, Opus 4.6, Sonnet 4.6.
There is no 1M-context entry. Sessions run at 500k.

• The CLI and the VS Code extension both list "Opus 5 with 1M context" as the

default entry and run at 1M, same account, same plan.

• In the desktop Code tab, /model opus[1m] is accepted and echoes

"Set model to opus[1m] (claude-opus-5[1m])", after which the status bar
reads "Unsupported model" and the session cannot send.

What Should Happen?

Expected

• The desktop app offers the same 1M variant as the other clients, or
• it rejects the alias up front with a clear message, instead of switching the

session to a model it cannot call.

Error Messages/Logs

unsupported model when running claude --model 'opus[1m]'

Steps to Reproduce

open the desktop and look for 1m models

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.278

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_