Model claude 4.5 Opus not found error with Anthropic api key

[marcus2000 (Marc Lamy)]

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

When I add my Anthropic API key in Cursor settings, requests fail with a 404 because Cursor sends the model name “claude-4.5-opus-high-thinking” to the Anthropic API, which doesn’t exist.

{“error”:{“type”:“provider”,“reason”:“provider_error”,“message”:“Provider returned 404”,“retryable”:false,“provider”:{“status”:404,“body”:“{"type":"error","error":{"type":"not_found_error","message":"model: claude-4.5-opus-high-thinking"},"request_id":"req_011CX5vfMFGRfdogH5Qdw4FT"}”}}}

Steps to Reproduce

Set api key in the settings

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

2.3.34.

For AI issues: which model did you use?

Opus and Sonnet

Does this stop you from using Cursor

No - Cursor works, but with this issue

[deanrie]

Hey, thanks for the report. This might’ve been a temporary error, or Anthropic may have misidentified the model name claude-4.5-opus-high-thinking (Cursor’s internal name).

Could you try manually adding this model name: claude-opus-4-5-20251101 and let me know if it works for you?

Can you confirm if this also happens with Claude Sonnet 4.5, or only with Opus?

[marcus2000 (Marc Lamy)]

@deanrie

Could you try manually adding this model name: claude-opus-4-5-20251101 and let me know if it works for you?

Adding the model name worked! I thought it would automatically do it for me