[BUG] Opus 4.5 identifies as Sonnet 4.5 with MAX plan.

[peixotorms]

Description

login with claude max.
Swich to Opus 4.5.

Ask:
Answer concisely: What is your model name, version number, and knowledge cutoff date?

Answer:
I'm Claude, made by Anthropic. My model name is Claude 4 Sonnet (claude-sonnet-4-20250514). My knowledge cutoff date is April 2024.

---

Please check if the correct model is being sent, or if this is the answer from Claude even while using Opus.

As comparison, Claude code says:

I am Claude Opus 4.5 by Anthropic.

  - Model ID: claude-opus-4-5-20251101
  - Knowledge cutoff: January 2025
  - Context: Running as Claude Code (Anthropic's official CLI tool)

So maybe either there is a bug on claude max implementation, or the model is not being sent correctly.

OpenCode version

v1.0.220

Steps to reproduce

login with claude max.
Swich to Opus 4.5.

Ask:
Answer concisely: What is your model name, version number, and knowledge cutoff date?

Screenshot and/or share link

No response

Operating System

No response

Terminal

No response

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Claude Max not working #4660: Claude Max not working

Feel free to ignore if this doesn't address your specific case.

[rekram1-node]

Not a bug, model is sent correctly, but claude code literally puts in the system prompt:

You are <Model>

SO that's why it wont fail to self identify

We will probably do the same just so people stop getting confused by this

Note that the vast majority LLMs cant self identify well at all

[peixotorms]

#5226 thanks