Generate

Create examples of any data type

The generate function creates realistic examples of any type. It transforms () → T, making it easy to produce:

• Test data (“Generate a plausible email address” → “[e-mail]”)
• Sample content (“Generate a product description” → “Sleek wireless earbuds with…”)
• Structured examples (“Generate a recipe” → Recipe(title=“Lemon Garlic Pasta”, ingredients=[…]))

For complex generation patterns, consider creating a custom task. The generate function is a convenient wrapper around Marvin’s task system - see Tasks for more details.

Usage

Generate a simple string:

import marvin

name = marvin.generate(
    str,
    instructions="Generate a fantasy character name"
)
print(name)

"Thaelar Moonweaver"

Parameters

• target: The type of data to generate
• n: Number of examples to generate (default: 1)
• instructions: Optional guidance for generation
• agent: Optional custom agent to use
• thread: Optional thread for conversation context
• context: Optional additional context

Async Support

The function is also available in an async version:

import marvin
import asyncio

async def main():
    result = await marvin.generate_async(
        str,
        instructions="Generate a company slogan"
    )
    print(result)  # "Innovation meets simplicity"

asyncio.run(main())

Examples

Multiple Examples

Generate a list of items:

import marvin

colors = marvin.generate(
    str,
    n=3,
    instructions="Generate color names"
)
print(colors)

["Cerulean Blue", "Crimson Red", "Forest Green"]

Structured Data

Generate complex objects:

import marvin
from dataclasses import dataclass
from typing import List

@dataclass
class Recipe:
    title: str
    ingredients: List[str]
    steps: List[str]

recipe = marvin.generate(Recipe)
print(f"Recipe: {recipe.title}")
print(f"First step: {recipe.steps[0]}")

"Recipe: Honey Glazed Salmon"
"First step: Preheat the oven to 400°F (200°C)"

With Context

Generate content with specific requirements:

import marvin

description = marvin.generate(
    str,
    instructions="Generate a product description",
    context="Target audience: tech-savvy professionals"
)
print(description)

"The XPS Pro 5000 ultrabook combines cutting-edge performance with enterprise-grade security features, perfect for remote work and intensive multitasking."

Collections

Generate lists and dictionaries:

import marvin
from typing import List, Dict

# Generate a list of strings
ingredients = marvin.generate(List[str], instructions="Generate recipe ingredients")
print(ingredients)

# Generate a dictionary
menu = marvin.generate(Dict[str, float], instructions="Generate menu items with prices")
print(menu)

["olive oil", "garlic", "pasta", "lemon", "parmesan cheese"]
{"Margherita Pizza": 12.99, "Caesar Salad": 8.99, "Tiramisu": 6.99}