Failed to connect to the Cursor agent Sonnet model

Bug Reports
1

Describe the Bug

Request ID: d3bb5fe0-40be-4e6e-a473-5258a386e3b6
{“error”:“ERROR_OPENAI”,“details”:{“title”:“Unable to reach the model provider”,“detail”:“We’re having trouble connecting to the model provider. This might be temporary - please try again in a moment.”,“additionalInfo”:{},“buttons”:},“isExpected”:false}
ConnectError: [unavailable] Error
at x9a.$endAiConnectTransportReportError (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:4757:223764)
at hir.S (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:17741)
at hir.Q (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:17519)
at hir.M (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:16607)
at hir.L (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:15708)
at Bwt.value (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:492:14500)
at ve.B (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:48:2398)
at ve.fire (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:48:2617)
at Git.fire (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:4744:10379)
at u.onmessage (vscode-file://vscode-app/d:/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:6968:12271)

Steps to Reproduce

Whenever I set the agent model to a Claude variant such as Sonnet 4 and try to prompt it, I consistently encounter the connection failure error mentioned above.

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

版本: 1.2.4 (user setup)
提交: 1.99.3
日期: a8e95743c5268be73767c46944a71f4465d05c90
Electron: 2025-07-10T17:09:01.383Z
ElectronBuildId: 34.5.1
Chromium: undefined
Node.js: 132.0.6834.210
V8: 20.19.0
OS: 13.2.152.41-electron.0

3

Hey, do you also have the API key for OpenAI enabled? If so, try disabling it and keep only the API key for Anthropic enabled.

5

I’m using the subscription-based service rather than a custom model. While Gemini 2.5 Pro functions normally, the Sonnet model consistently fails to work.

6

Oh, sorry, I misunderstood. Have you also tried creating a new chat?

7

I tried creating a new chat, and it works fine there. But why doesn’t it work properly in the current window?

8

This happens if the chat context is overloaded or if you switch models during the conversation. We’ve fixed this in version 1.3, which should be released soon.