Fails to connect vscode IDE from devcontainer

[rajinder-yadav]

What happened?

Installed Gemini CLI from VSCode Insider using pnpm and then installed the VSCode Gemini CLI plugin. Gemini CLI fails to connect to the IDE after it's run from the terminal in VSCode.

What did you expect to happen?

CLI to connect to VSCode Insider running from a DevContainer.

Client information

Client Information

Run gemini to enter the interactive CLI, then run the /about command.

> /about
# paste output here
About Gemini CLI                                                                                                                                                                       │ 
│                                                                                                                                                                                        │ 
│ CLI Version                                                     0.17.0                                                                                                                 │ 
│ Git Commit                                                      7c684e36f                                                                                                              │ 
│ Model                                                           auto                                                                                                                   │ 
│ Sandbox                                                         no sandbox                                                                                                             │ 
│ OS                                                              linux                                                                                                                  │ 
│ Auth Method                                                     OAuth                                                                                                                  │ 
│ IDE Client                                                      VS Code                                                                                                                │ 
│                                                                                    

Operating System: Fedora Linux 43
KDE Plasma Version: 6.5.2
KDE Frameworks Version: 6.20.0
Qt Version: 6.10.0
Kernel Version: 6.17.7-300.fc43.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 5900X 12-Core Processor
Memory: 64 GiB of RAM (62.7 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 3080
Manufacturer: ASUS

Login information

I was able to login to Google Account.

Anything else we need to know?

No response

[gemini-cli]

Found possible duplicate issues:

• Gemini CLI can't connect to VSCode #6372
• gemini vscode /ide enable failed #8076
• Can not connect Gemini Cli Agent and VSCode #11370
• Unable to connect to IDE in version 0.10.0 and 0.12.0 #11771
• Cannot connect to VS Code plugin #8704
• [ERROR] [IDEClient] Failed to connect to IDE companion extension for VS Code (in Cursor Dev Container) #7640
• IDE integration does not work in various containers #7426

If you believe this is not a duplicate, please remove the status/possible-duplicate label.

[vqvu]

I'm running into this problem too. The CLI complains with

✕ 🔴 Disconnected: Failed to connect to IDE companion extension in VS Code. Please ensure the extension is running. To install the extension, run /ide install.

I think this was broken by #8512, which changed the IDE server to only accept connections sent to localhost or 127.0.0.1. The client will connect to host.docker.internal when inside a docker container.

Indeed,curl returns the expected Invalid Host header from that PR.

$ curl host.docker.internal:$GEMINI_CLI_IDE_SERVER_PORT/mcp
{"error":"Invalid Host header"}⏎ 

[Duncan3142]

Same here