[Idea] VS Code Extension for GoNB – Seamless Go Notebook Experience inside VS Code

[sushink70]

Currently, GoNB runs great as a Jupyter notebook kernel.
Native VS Code Notebook Integration
Enable .ipynb or .gonb files to run cells using the GoNB kernel.
Convert .ipynb ↔ .gonb notebooks easily.

[janpfeifer]

This sounds like a great idea. I don't use VS Code, would you know what needs to be done to assign ".gonb" to a Jupyter Notebook with a GoNB kernel in VS Code ?

Is it something that I can do in GoNB, or does it require writing some form of VSCode extension ?

[sushink70]

Hi @janpfeifer,

I tried to integrate gonb with vscode jupyter extension and it worked - Debian (kali linux - 6.16.8+kali-amd64)
.ipynb is enough to run the golang code and .gonb not mandatory(but recommended). But getting some error while running raw code without main(). Is that expected?

sudo apt install golang-go
sudo apt install jupyter-notebook
sudo apt install jupyter-core

go install github.com/janpfeifer/gonb@latest
go install golang.org/x/tools/cmd/goimports@latest
go install golang.org/x/tools/gopls@latest

export PATH=$PATH:$(go env GOPATH)/bin
gonb --install

2025-11-16 11:32:51.561 [info] Try to start language server - activation (enabled: true)
2025-11-16 11:32:51.894 [info] Running language server gopls(v0.20.0/go1.24.9)

VSCode
Version: 1.105.1
Commit: 7d842fb85a0275a4a8e4d7e040d2625abbf7f084
Date: 2025-10-14T22:33:36.618Z
Electron: 37.6.0
ElectronBuildId: 12502201
Chromium: 138.0.7204.251
Node.js: 22.19.0
V8: 13.8.258.32-electron.0
OS: Linux x64 6.16.8+kali-amd64

[janpfeifer]

Nice @sushink70 , congrats on getting it to work on VSCode!

So the issue you are experiencing is covered as the very first item in the tutorial. It's an idiosyncrasy of GoNB:

• To run anything a cell needs a main function. It can also only define functions and variables, and not have a main. Then GoNB only memorizes the functions and variables to future (other cells) use.
• Because writing func main() { } in every cell is too repetitive, GoNB provides the special tag %%: any lines after that are automatically included in a func main() {...}
• GoNB automatically includes package main in your cells. You should not include it.
• Most standard library packages will be imported automatically for you (using goimports).

So to make your example work:

type Person struct {
    Name string
    Age int
}

%%
p := Person{Name: "Alice", Age 30}
fmt.Printf("%+v\n", p)

Does it make sense ?

[janpfeifer]

Alternative, using multiple cells:

• Cell 1: no main, only memorizes the type Person:

type Person struct {
    Name string
    Age int
}

• Cell 2: with a main (implicitly defined by the %% tag), uses the Person defined in the other cell:

%%
p := Person{Name: "Alice", Age 30}
fmt.Printf("%+v\n", p)

[sushink70]

The syntax you provide is working without main(). Thanks.

[janpfeifer]

hey @sushink70 , I'm closing the issue for now. But feel free to reopen it, or open a new one if you need anything related.