[BUG] Sonnet 4.5 not found in Claude Code

[mortsnort]

Problem (one or two sentences)

I get this error when trying to use Claude Code - Sonnet 4.5

API Request Failed
{"type":"error","error":{"type":"not_found_error","message":"model: claude-4.5-sonnet"},...

Context (who is affected and when)

Happens when user tries to use Claude Code as provider and Sonnet 4.5 as the model.

Reproduction steps

Set provider to Claude Code, select Sonnet 4.5 as the model. Try to do any coding.

Expected result

The model performs the task

Actual result

Model not found error

Variations tried (optional)

No response

App Version

3.28.11 (098671c)

API Provider (optional)

None

Model Used (optional)

Claude Code - Claude 4.5 Sonnet

Roo Code Task Links (optional)

No response

Relevant logs or errors (optional)

I'm exploring a potential fix for the model name issue with Claude 4.5 Sonnet and will open a PR to share progress.

I've been investigating this issue and have some questions about the requirements before creating the PR:

The error message shows "model: claude-4.5-sonnet" which appears to be an incorrect model name. I found that:

1. The correct model name should be "claude-sonnet-4-5" (as defined in the Anthropic and Claude Code providers)
2. I initially fixed a similar incorrect name in the Vertex provider, but I'm not certain this addresses your specific issue

Could you help clarify:

• Are you using Claude Code with Vertex AI integration enabled, or just the standard Claude Code provider?
• When you select "Sonnet 4.5" in the UI, which exact model appears in the dropdown?

This will help ensure the implementation meets your expectations. Thanks!

[geminixiang]

That's correct, the model name displayed in GCP VertexAI is claude-sonnet-4-5.

[cshahdev]

Seems like the correct model name is claude-sonnet-4-5-20250929
Reference - https://docs.claude.com/en/docs/about-claude/models/overview

[mrubens]

Are you still having problems with this in the latest version of Roo Code and Claude Code 2.0?

[cshahdev]

I believe I am having this problem in Kilo Code and based on what I can see in b264495 it's yet to be fixed in Kilo code.

[coldgiraffe]

anyone can help?

I can install sonnet4.5 in my chat interface and mac local terminal, but just cant install it in either cursor or vs code terminal.