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Javascript Skill

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zeenie-ai
javascript-skill

Execute JavaScript code for calculations, data processing, and JSON manipulation. Full ES2022+ support on the bun runtime (Node-compatible APIs).

Overview

Publisherzeenie-ai
RepositoryOpenCompany
Skill namejavascript-skill
Stars
912
Forks
137
Bundled files
Instructions only
LicenseMIT
Links
  • Markdown instructions

    A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.

  • Works with any LLM

    AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.

  • Self-contained

    Everything the model needs lives in the instructions — no extra files to sync.

  • Open source

    Published by zeenie-ai on GitHub. Read the source before you install it.

Installation

Install the Javascript Skill AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

1

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills
git clone --depth 1 https://github.com/zeenie-ai/OpenCompany.git /tmp/OpenCompany
mkdir -p .claude/skills
cp -r /tmp/OpenCompany/server/skills/coding_agent/javascript-skill .claude/skills/javascript-skill
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Javascript Skill in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Javascript Skill on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Javascript Skill is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

  • Loaded only when it is needed

    The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.

  • Switch models mid-chat

    Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

JavaScript Code Execution Tool

Execute JavaScript code for calculations, data processing, and JSON manipulation.

How It Works

This skill provides instructions for the JavaScript Executor tool node. Connect the JavaScript Executor node to Zeenie's input-tools handle to enable JavaScript code execution.

javascript_code Tool

Execute JavaScript code and return results.

Schema Fields

FieldTypeRequiredDescription
codestringYesJavaScript code to execute

Available Features

FeatureDescription
ES6+ syntaxArrow functions, destructuring, spread operator
JSONJSON.parse() and JSON.stringify()
MathMathematical operations
DateDate and time manipulation
Array methodsmap, filter, reduce, sort, etc.
Object methodskeys, values, entries, assign
String methodsAll standard string methods

Built-in Variables

VariableDescription
input_dataData from connected workflow nodes (object)
outputSet this to return a result

Output Methods

  1. Set output variable: Returns structured data to the workflow
  2. Use console.log(): Captured as console output

Examples

Basic calculation:

json
{
  "code": "const result = 25 * 4 + 10;\nconsole.log(`Result: ${result}`);\noutput = result;"
}

Array processing:

json
{
  "code": "const numbers = input_data.numbers || [1, 2, 3, 4, 5];\nconst total = numbers.reduce((a, b) => a + b, 0);\nconst average = total / numbers.length;\nconsole.log(`Total: ${total}, Average: ${average}`);\noutput = { total, average };"
}

Filter array:

json
{
  "code": "const numbers = input_data.numbers || [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];\nconst evens = numbers.filter(n => n % 2 === 0);\nconsole.log(`Even numbers: ${evens}`);\noutput = evens;"
}

Transform data:

json
{
  "code": "const users = input_data.users || [{name: 'John', age: 30}, {name: 'Jane', age: 25}];\nconst names = users.map(u => u.name);\nconsole.log(`Names: ${names.join(', ')}`);\noutput = names;"
}

JSON manipulation:

json
{
  "code": "const data = { name: 'John', age: 30, city: 'NYC' };\nconst json = JSON.stringify(data, null, 2);\nconsole.log(json);\noutput = data;"
}

Object operations:

json
{
  "code": "const obj = { a: 1, b: 2, c: 3 };\nconst keys = Object.keys(obj);\nconst values = Object.values(obj);\nconst sum = values.reduce((a, b) => a + b, 0);\nconsole.log(`Sum of values: ${sum}`);\noutput = { keys, values, sum };"
}

Date operations:

json
{
  "code": "const now = new Date();\nconst tomorrow = new Date(now.getTime() + 24 * 60 * 60 * 1000);\nconst formatted = tomorrow.toISOString().split('T')[0];\nconsole.log(`Tomorrow: ${formatted}`);\noutput = formatted;"
}

Sort array:

json
{
  "code": "const items = input_data.items || ['banana', 'apple', 'cherry'];\nconst sorted = [...items].sort();\nconsole.log(`Sorted: ${sorted}`);\noutput = sorted;"
}

String processing:

json
{
  "code": "const text = 'Hello World, Hello JavaScript';\nconst words = text.split(' ');\nconst unique = [...new Set(words)];\nconsole.log(`Unique words: ${unique}`);\noutput = unique;"
}

Destructuring and spread:

json
{
  "code": "const { name, age } = input_data.user || { name: 'John', age: 30 };\nconst profile = { name, age, active: true };\nconst extended = { ...profile, role: 'admin' };\nconsole.log(JSON.stringify(extended));\noutput = extended;"
}

Response Format

Success:

json
{
  "success": true,
  "result": { "total": 15, "average": 3 },
  "output": "Total: 15, Average: 3"
}

Error:

json
{
  "error": "ReferenceError: undefinedVar is not defined"
}

Use Cases

Use CaseApproach
Array manipulationUse map, filter, reduce
JSON processingUse JSON.parse, JSON.stringify
Object operationsUse Object.keys, values, entries
String processingUse split, join, replace
Math calculationsUse Math methods
Date operationsUse Date object
Data transformationUse spread and destructuring

Guidelines

  1. Always set output: This returns data to the workflow
  2. Use console.log() for debugging: Output is captured and returned
  3. Use ES6+ features: Arrow functions, destructuring, spread
  4. Handle undefined: Use || defaultValue pattern
  5. Keep code focused: One task per execution
  6. No network access: Use http-skill for web requests
  7. Timeout: Default 30 seconds max execution time

Security Restrictions

  • No network/fetch operations
  • No file system access (no require('fs'))
  • No child processes
  • Limited execution time (30 seconds)
  • Sandboxed environment

Common Patterns

Default values:

javascript
const data = input_data.value || 'default';

Null-safe access:

javascript
const name = input_data?.user?.name || 'Unknown';

Array to object:

javascript
const arr = [{id: 1, name: 'A'}, {id: 2, name: 'B'}];
const obj = Object.fromEntries(arr.map(x => [x.id, x.name]));

Setup Requirements

  1. Connect the JavaScript Executor node to Zeenie's input-tools handle
  2. bun must be available to the backend (the desktop app bundles it; the terminal install requires it)

Frequently asked questions

What does the Javascript Skill AI skill do?

Execute JavaScript code for calculations, data processing, and JSON manipulation. Full ES2022+ support on the bun runtime (Node-compatible APIs).

Why use Javascript Skill on TypingMind?

Because you install it once and use it with any model. Javascript Skill is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Javascript Skill in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/zeenie-ai/OpenCompany/tree/main/server/skills/coding_agent/javascript-skill. TypingMind reads its SKILL.md and installs it as a skill you can enable per chat.

Which AI models can use Javascript Skill?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Javascript Skill?

As many as you like. As long as a model supports skills, you can use Javascript Skill with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Javascript Skill AI skill free?

Yes. It is published on GitHub by zeenie-ai under the MIT license. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

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