API Request Failed after upgrading from v3.20.3 to v3.26.3

[tanawatpan]

App Version

3.26.3

API Provider

OpenAI Compatible

Model Used

Self-hosted VLLM openai/gpt-oss-120b

Roo Code Task Links (Optional)

No response

🔁 Steps to Reproduce

Environment

• OS: Ubuntu 22.04 (remote machine)
• VSCode Version: 1.103.2
• Roo Code Extension Version: 3.21.x - 3.26.3 (issue present), 3.20.3 (working)
• Network: Corporate network with HTTP proxy
• Model: Self-hosted vLLM openai/gpt-oss-120b

Description

After upgrading the Roo Code extension from version 3.20.3 to 3.26.3, I'm unable to chat with my self-hosted vLLM openai/gpt-oss-120b. The extension returns "API Request Failed, Connection error." when attempting to use the chat functionality.

Steps to Reproduce

1. Have Roo Code 3.20.3 installed with self-hosted vLLM configured
2. Upgrade to Roo Code 3.26.3
3. Attempt to chat with the model
4. Observe the connection error

Version Testing Results

• ✅ v3.20.3: Working correctly
• ❌ v3.21.x: Connection error
• ❌ v3.22.x: Connection error
• ❌ v3.23.x: Connection error
• ❌ v3.24.x: Connection error
• ❌ v3.25.x: Connection error
• ❌ v3.26.x: Connection error

Additional Context

• The self-hosted VLLM server is accessible and responding correctly
• No changes were made to the server configuration
• The issue appears to be introduced after version 3.20.3
• Working behind corporate firewall with HTTP proxy configuration

💥 Outcome Summary

Expected Behavior

The extension must connect to the self-hosted VLLM API and function as it did in version 3.20.3.

Actual Behavior

Error message: "API Request Failed, Connection error."

📄 Relevant Logs or Errors (Optional)

[roomote]

I'm exploring a potential fix for the connection error with self-hosted vLLM OpenAI-compatible APIs that started appearing after version 3.20.3. I'll investigate the changes between 3.20.3 and 3.21.x that might have affected proxy/connection handling and will open a PR to share progress.

[roomote]

Opened PR #7574 with my attempt at addressing this issue: #7574

The PR adds comprehensive proxy support for OpenAI-compatible providers by:

• Respecting standard proxy environment variables (HTTP_PROXY, HTTPS_PROXY, NO_PROXY)
• Supporting both uppercase and lowercase variants
• Handling NO_PROXY bypass patterns including wildcards
• Integrating proxy configuration with all OpenAI client types

All tests are passing locally. The CI checks are currently running on the PR. Feedback welcome!

[daniel-lxs]

Hey @tanawatpan Thank you for reporting this, can you confirm that downgrading solves your issue?

[tanawatpan]

Hi @daniel-lxs, Yes, downgrading to Roo Code v3.20.3 resolves the issue without any configuration changes.