Malarky

Generate syntactically plausible English nonsense, steered by lexicons.

Malarky is a faker-like library and CLI that produces grammatically correct English text that sounds meaningful but isn't. Perfect for:

• Placeholder text generation (like Lorem Ipsum, but in English)
• Testing and mocking
• Creative writing prompts
• Procedural content generation
• Corporate buzzword bingo

Features

• Syntactically correct -- Proper grammar, subject-verb agreement, punctuation
• Lexicon-driven -- Guide output with custom vocabularies and style presets
• Deterministic -- Seedable RNG for reproducible output
• Configurable -- Control sentence types, lengths, complexity
• Output transforms -- Pipe text through built-in transforms (Pig Latin, leet speak, pirate, and more)
• Traceable -- Debug mode shows exactly how text was generated
• Full CLI -- Generate text, apply transforms, and validate lexicons from the command line
• Zero dependencies -- Works standalone or with @faker-js/faker

Installation

npm install malarky

Source Code & Issues

Source: https://github.com/JPaulDuncan/malarky

Issues: https://github.com/JPaulDuncan/malarky/issues

Additional Usage: https://jpaulduncan.github.io/malarky/usage.md

License: MIT

Quick Start

TypeScript / JavaScript

import { TextGenerator, SimpleFakerAdapter } from 'malarky';

const generator = new TextGenerator({
  fakerAdapter: new SimpleFakerAdapter(),
});

generator.setSeed(42);

console.log(generator.sentence());
// "Generally, the change called."

console.log(generator.paragraph({ sentences: 3 }));
// Three sentences of plausible nonsense

console.log(generator.textBlock({ paragraphs: 2 }));
// Two paragraphs of corporate-sounding malarky

Command Line

# Generate a sentence
malarky sentence

# Generate a deterministic question
malarky sentence --seed 42 --type question

# Generate a paragraph with a corporate lexicon
malarky paragraph --sentences 5 --lexicon ./corp.json --archetype corporate

# Apply Pig Latin transform and output as JSON
malarky sentence --seed 42 --transform pigLatin --json

CLI

After installing globally (npm install -g malarky) or locally, the malarky command is available.

Commands

| Command | Description | | ----------- | ------------------------------------------- | | sentence | Generate one or more sentences | | paragraph | Generate one or more paragraphs | | text | Generate a text block (multiple paragraphs) | | validate | Validate a lexicon JSON file | | list | List available transforms or sentence types |

Global Options

These options work with sentence, paragraph, and text:

| Option | Short | Description | | -------------------- | ----- | ------------------------------------------------------- | | --seed <n> | -s | RNG seed for deterministic output | | --lexicon <path> | -l | Path to a lexicon JSON file | | --archetype <name> | -a | Archetype to activate from the lexicon | | --transform <id> | -x | Apply an output transform (repeatable, comma-separated) | | --trace | -t | Output JSON trace to stderr | | --json | -j | Output full result as JSON to stdout | | --count <n> | -n | Number of items to generate (default: 1) | | --help | -h | Show help | | --version | -v | Show version |

Generating Sentences

# Random sentence
malarky sentence

# Specific type
malarky sentence --type question
malarky sentence --type compound
malarky sentence --type subordinate

# Control word count
malarky sentence --min-words 10 --max-words 20

# Multiple sentences
malarky sentence --count 5

# With hints (activate lexicon tags)
malarky sentence --hints domain:tech,register:formal

Generating Paragraphs

# Random paragraph
malarky paragraph

# Control sentence count
malarky paragraph --sentences 5
malarky paragraph --min-sentences 3 --max-sentences 8

# Multiple paragraphs
malarky paragraph --count 3

Generating Text Blocks

# Random text block
malarky text

# Control paragraph count
malarky text --paragraphs 4
malarky text --min-paragraphs 2 --max-paragraphs 6

Applying Transforms

Use --transform (or -x) to pipe generated text through built-in transforms:

# Pig Latin
malarky sentence --seed 42 --transform pigLatin
# "Enerallygay, ethay angechay alledcay."

# Leet speak
malarky sentence --seed 42 --transform leet

# Chain multiple transforms (comma-separated)
malarky sentence --seed 42 --transform leet,uwu

# Or use repeated flags
malarky sentence --seed 42 -x pirate -x mockCase

Run malarky list transforms to see all available transforms.

JSON Output

Use --json (or -j) to get structured output including metadata and trace:

malarky sentence --seed 42 --json

{
  "text": "Generally, the change called.",
  "trace": { "...": "..." },
  "meta": {
    "archetype": "default",
    "seed": 42
  }
}

Validating Lexicons

# Human-readable output
malarky validate ./my-lexicon.json

# Machine-readable JSON output
malarky validate ./my-lexicon.json --json

Listing Available Features

# List all output transforms
malarky list transforms

# List all sentence types
malarky list types

# Output as JSON
malarky list transforms --json

Output Transforms

Malarky includes 10 built-in output transforms that modify generated text at the token level. All transforms are deterministic (same seed = same output) and safe to chain.

| Transform | Description | | -------------- | ------------------------------------- | | pigLatin | Classic Pig Latin | | ubbiDubbi | Ubbi Dubbi language game | | leet | Leetspeak character substitution | | uwu | Cute speak (w-substitution, suffixes) | | pirate | Pirate speak | | redact | Redact/mask words | | emoji | Add emoji replacements | | mockCase | rAnDoM cAsE aLtErNaTiOn | | reverseWords | Reverse word order | | bizJargon | Business jargon patterns |

Using Transforms in Code

const result = generator.sentence({
  outputTransforms: {
    enabled: true,
    pipeline: [{ id: 'pigLatin' }],
  },
});

Transforms can also be configured at the lexicon level or per-archetype in your lexicon JSON. See the usage guide for details.

Sentence Types

Malarky generates six sentence structures:

// Simple declarative: "The system processes data."
generator.sentence({ type: 'simpleDeclarative' });

// Question: "Does the team deliver results?"
generator.sentence({ type: 'question' });

// Compound: "The strategy evolved, and the metrics improved."
generator.sentence({ type: 'compound' });

// Subordinate clause: "Because the pipeline scales, the throughput increases."
generator.sentence({ type: 'subordinate' });

// Intro adverbial: "Furthermore, the initiative drives innovation."
generator.sentence({ type: 'introAdverbial' });

// Interjection: "Indeed, the team delivered results."
generator.sentence({ type: 'interjection' });

Deterministic Output

Same seed produces the same text every time:

generator.setSeed(12345);
const a = generator.sentence();

generator.setSeed(12345);
const b = generator.sentence();

console.log(a === b); // true

From the CLI:

malarky sentence --seed 12345
malarky sentence --seed 12345
# Both print the same sentence

Custom Lexicons

Create domain-specific malarky with JSON lexicon files:

{
  "id": "lexicon.startup",
  "language": "en",
  "termSets": {
    "noun.startup": {
      "pos": "noun",
      "tags": ["domain:startup"],
      "terms": [
        { "value": "disruptor", "weight": 5 },
        { "value": "unicorn", "weight": 3 },
        { "value": "pivot", "weight": 4 },
        { "value": "runway", "weight": 2 }
      ]
    },
    "verb.startup": {
      "pos": "verb",
      "tags": ["domain:startup"],
      "terms": [
        { "value": "disrupt", "weight": 5 },
        { "value": "scale", "weight": 4 },
        { "value": "pivot", "weight": 3 },
        { "value": "iterate", "weight": 3 }
      ]
    }
  },
  "archetypes": {
    "startup": {
      "tags": ["domain:startup"]
    }
  }
}

Load it in code:

import {
  TextGenerator,
  SimpleFakerAdapter,
  loadLexiconFromString,
} from 'malarky';
import { readFileSync } from 'fs';

const lexicon = loadLexiconFromString(readFileSync('./startup.json', 'utf-8'));

const generator = new TextGenerator({
  fakerAdapter: new SimpleFakerAdapter(),
  lexicon,
});

generator.setArchetype('startup');
console.log(generator.paragraph());

Or from the CLI:

malarky paragraph --lexicon ./startup.json --archetype startup

See the usage guide for the full lexicon schema reference.

Morphology Utilities

Malarky exports standalone English morphology functions:

import {
  pluralize,
  singularize,
  getPastTense,
  getPresentParticiple,
  getThirdPersonSingular,
  getIndefiniteArticle,
} from 'malarky';

pluralize('synergy'); // "synergies"
pluralize('child'); // "children"
singularize('stakeholders'); // "stakeholder"
getPastTense('leverage'); // "leveraged"
getPastTense('go'); // "went"
getPresentParticiple('run'); // "running"
getThirdPersonSingular('do'); // "does"
getIndefiniteArticle('hour'); // "an"
getIndefiniteArticle('user'); // "a"

With @faker-js/faker

For more word variety, use the optional faker-js adapter:

import { TextGenerator, FakerJsAdapter } from 'malarky';
import { faker } from '@faker-js/faker';

const generator = new TextGenerator({
  fakerAdapter: new FakerJsAdapter(faker),
});

@faker-js/faker is an optional peer dependency -- Malarky works without it using the built-in SimpleFakerAdapter.

Configuration

Fine-tune generation behavior:

const generator = new TextGenerator({
  fakerAdapter: new SimpleFakerAdapter(),
  config: {
    minWordsPerSentence: 10,
    maxWordsPerSentence: 25,
    minSentencesPerParagraph: 3,
    maxSentencesPerParagraph: 6,
    questionRate: 0.05,
    compoundRate: 0.2,
    subordinateClauseRate: 0.15,
    maxPPChain: 2,
    maxAdjectivesPerNoun: 2,
  },
});

See the usage guide for all configuration options.

Tracing

Enable trace mode to see how text was generated:

const generator = new TextGenerator({
  fakerAdapter: new SimpleFakerAdapter(),
  enableTrace: true,
});

const result = generator.sentence();

console.log(result.text);
// "The robust system efficiently processes data."

console.log(result.trace.paragraphs[0].sentences[0].template);
// "simpleDeclarative"

console.log(result.trace.paragraphs[0].sentences[0].tokens);
// [{ value: "The", source: "default" }, { value: "robust", source: "adj.business" }, ...]

From the CLI, use --trace to send trace data to stderr, or --json to include it in structured stdout output.

Examples

# Run the basic usage example
npm run example:basic

# Run the corporate lexicon example
npm run example:corporate

Development

# Install dependencies
npm install

# Build
npm run build

# Run tests (watch mode)
npm test

# Run tests once
npm run test:run

# Run tests with coverage
npm run test:coverage

# Lint
npm run lint

API Summary

For the complete API reference including all types, interfaces, and configuration options, see the usage guide.

| Method / Function | Description | | ------------------------------ | ------------------------------------ | | new TextGenerator(opts) | Create a generator instance | | generator.sentence(opts?) | Generate one sentence | | generator.paragraph(opts?) | Generate a paragraph (2-7 sentences) | | generator.textBlock(opts?) | Generate multiple paragraphs | | generator.setSeed(n) | Set RNG seed for reproducibility | | generator.setLexicon(lex) | Load or replace a lexicon at runtime | | generator.setArchetype(name) | Activate a style preset | | validateLexicon(obj) | Validate a lexicon object | | loadLexiconFromString(json) | Parse a lexicon JSON string |

License

MIT

"Leveraging synergistic paradigms to facilitate robust deliverables across the ecosystem." -- malarky