create-script-handler - SKILL.md Agent Skill

name: create-script-handler description: Create a custom script handler for an unsupported scripting language when-to-use: When user asks to add support for a new scripting language or create a script handler effort: medium

Create Script Handler

Help the user register a custom script handler so Datagrok can run scripts in a language not natively supported.

Usage

/create-script-handler [language-name] [--package <package-name>]

Instructions

1. Define the handler function

Create a TypeScript function that accepts a DG.FuncCall and executes the script, setting output parameters on completion:

export async function myLanguageHandler(call: DG.FuncCall): Promise<void> {
  // Read input parameters from call.inputs
  // Execute the script (e.g., via WebAssembly or a Docker container)
  // Set output parameters on call.outputs
}

The implementation can use any execution strategy: WebAssembly, a Docker container, a remote API, etc.

2. Add mandatory annotations

Place these multi-line comments above the function declaration:

//tags: scriptHandler
//meta.scriptHandler.language: clojure
//meta.scriptHandler.extensions: clj,cljs,cljr
//meta.scriptHandler.commentStart: ;
//input: funccall scriptCall
export async function clojureScriptHandler(call: DG.FuncCall): Promise<void> {
  // implement handler
}

Mandatory annotations

Annotation	Description
`tags: scriptHandler`	Marks the function as a script handler for registration
`meta.scriptHandler.language`	Language name (shown in UI when creating scripts)
`meta.scriptHandler.extensions`	Comma-separated file extensions (e.g., `py`, `js`, `clj,cljs,cljr`)
`input: funccall scriptCall`	The handler must accept exactly one input of type `funccall`

Optional annotations

Annotation	Description
`meta.scriptHandler.templateScript`	Template code added to newly created scripts in this language
`meta.scriptHandler.codeEditorMode`	CodeMirror editor mode for syntax highlighting (available modes)
`meta.icon`	Path to icon inside package files, used in UI for all scripts of this language
`meta.scriptHandler.vectorizationFunction`	Function in form `<namespace>:<function name>` for vectorizing `DG.Script`. Accepts `DG.Script`, returns string with vectorized code.
`meta.scriptHandler.commentStart`	Comment character(s) for the language (e.g., `;` for Clojure, `#` for Python)

3. Publish the package

Build and publish the package:

webpack
grok publish dev

After publishing, the language appears in the script creation UI. The platform recognizes scripts with a matching language annotation and routes them to this handler.

Complete example

import * as DG from 'datagrok-api/dg';

//tags: scriptHandler
//meta.scriptHandler.language: clojure
//meta.scriptHandler.extensions: clj,cljs,cljr
//meta.scriptHandler.commentStart: ;
//meta.scriptHandler.codeEditorMode: clojure
//meta.scriptHandler.templateScript: (println "Hello, World!")
//meta.icon: images/clojure-icon.png
//input: funccall scriptCall
export async function clojureScriptHandler(call: DG.FuncCall): Promise<void> {
  const script = call.inputs['scriptCall'];
  // Execute the Clojure code
  // Set outputs: call.setParamValue('result', value);
}

Behavior

Ask the user which programming language they want to support.
Ask for the file extensions associated with that language.
Determine the execution strategy (WebAssembly, Docker container, remote service, etc.).
Generate the handler function with all mandatory annotations.
Add optional annotations (template, icon, editor mode) if the user provides them.
If Docker execution is needed, suggest also using the /create-docker-container skill.
Ensure the function signature has exactly one funccall input parameter.
Follow project coding conventions: no excessive comments, no curly brackets for one-line if/for, catch/else if on new lines.