Code Runner — Obsidian Plugin

Run code blocks interactively in Obsidian with full stdin input support. Python runs locally via Pyodide (WebAssembly); 17+ other languages execute via public playground APIs.

Features

Hybrid Interactive Input (Python)

Code Runner provides the most complete Python input experience of any Obsidian plugin:

Platform	Mode	Behavior
Desktop (SAB available)	Interactive	Pre-fill the first input() prompt, then each subsequent input() triggers an inline popup in real time — type and press Enter as the program runs
Tablet / Mobile (no SAB)	Pre-fill	All input() prompts are parsed and shown as labeled fields. Loop-based programs get a raw textarea for unlimited lines

• Input history: Every prompt→response pair is displayed above the output, visible during and after execution
• Stop button: Terminate runaway programs during interactive execution
• Auto-detection: input() inside while/for loops is detected automatically; tablet mode switches to a multi-line textarea

Multi-Language Support

Language	Backend	stdin
Python	Pyodide v0.26.x (local WASM)	✅
C	SoloLearn API (remote)	✅
C++	SoloLearn API (remote)	✅
Java	SoloLearn API (remote)	✅
Go	SoloLearn API (remote)	✅
C#	SoloLearn API (remote)	✅
Swift	SoloLearn API (remote)	✅
R	SoloLearn API (remote)	✅
JavaScript	Proxy-sandboxed eval (local)	—
TypeScript	Compiled → JS (local)	—
Rust	Rust Playground API (remote)	—
Kotlin	Kotlin Playground API (remote)	—
Haskell	Haskell Playground API (remote)	—
Crystal	Crystal Playground API (remote)	—
V (Vlang)	V Playground API (remote)	—
Wenyan	wenyan-lang CDN (local)	—
HTML	Shadow DOM render (local)	—

Quality of Life

• Output cache: Results persist across note switches via localStorage
• ANSI color support: Terminal color codes are rendered in output
• Matplotlib: Python matplotlib figures render inline (desktop)
• Plugin API: Other plugins can programmatically execute code via app.plugins.plugins['code-runner'].api

Installation

Manual

1. Download main.js, manifest.json, styles.css from the latest release
2. Create <vault>/.obsidian/plugins/code-runner/ and copy the 3 files in
3. Settings → Community Plugins → Enable "Code Runner"

Community Plugin (pending approval)

Once approved, install directly via Settings → Community Plugins → Browse → "Code Runner".

Usage

Create a fenced code block with a language tag:

```python
name = input("Enter your name: ")
age  = input("Enter your age: ")
print(f"Hello {name}, you are {age} years old!")
```

• Click the ⌨ keyboard icon (bottom-right of the code block) to open the input form
• Fill in your input values and click ▶ to run
• Output appears below the code block

Input Format

• Python: Each line feeds one input() call
• C / C++ / Java / Go / C# / Swift / R: Separate values with spaces (fed to the program's stdin stream)

Architecture

Code Block → needsStdin() → Show pre-fill form (optional)
                │
          ┌─────┴─────┐
     SAB available?    │
     ┌───┴───┐         │
    Yes     No         │
     │       │         │
  Worker   Main-thread │
  + SAB    Pyodide     │
  (inter-  (pre-fill   │
  active)  only)       │
                       │
          Output ←─────┘

• Worker + SharedArrayBuffer: Desktop mode. Atomics.wait/notify synchronously blocks the Worker for interactive input without freezing the UI
• Main-thread Pyodide: Tablet/mobile fallback. All input must be provided before execution

Building From Source

git clone https://github.com/chujiu-dev/obsidian-code-runner.git
cd obsidian-code-runner
npm install
npm run build
# Output: dist/main.js, dist/styles.css, dist/manifest.json

Credits

Forked from Code Emitter by YISH (MIT). Key additions:

• Hybrid stdin system: pre-fill + Worker/SAB interactive input
• Full Python input() support via builtins.input replacement (Pyodide v0.26.x / Python 3.12)
• Tablet/mobile fallback with auto-detection of loop-based interactive programs
• Input history, stop button, output caching, ANSI color rendering

License

MIT — see LICENSE.