Core Functions

This document covers the primary functions used to interact with LLMs in OpenHosta.

emulate

The emulate function is the main feature. It uses the function's prototype and docstring as a prompt to emulate the behavior using AI.

from OpenHosta import emulate

def translate(text: str, language: str) -> str:
    """Translates the text into the specified language."""
    return emulate()

print(translate("Hello", "French"))

[!TIP] The Streaming Upgrade: If you change the return type from list[T] to Iterator[T], OpenHosta automatically switches to streaming mode, allowing you to process items as they are generated by the model.

emulate_async

Useful for web applications, heavy IO, or executing multiple LLM calls in parallel without blocking the main event loop.

import asyncio
from OpenHosta import emulate_async

async def capitalize_cities(sentence: str) -> str:
    """Capitalize the first letter of all city names in a sentence."""
    return await emulate_async()

print(asyncio.run(capitalize_cities("je suis allé à paris")))

emulate_variants

Explores the LLM's probability distribution to generate independent, alternative responses (variants) based on token logprobs. It is ideal for exploring uncertainty or generating diverse candidates from a single prompt.

It automatically adapts to the return type annotation: - If -> list[T]: Returns a fully resolved list of variants. - If -> Iterator[T]: Returns a generator that yields variants as they are found.

from typing import Iterator
from OpenHosta import emulate_variants

# Returns a list of variants once all are found
def list_variants(topic: str) -> list[str]:
    """Suggest three alternative creative names for a project."""
    return emulate_variants(min_probability=1e-2)

# Yields variants one by one
def stream_variants(topic: str) -> Iterator[str]:
    """Yield multiple alternative titles based on the topic."""
    yield from emulate_variants(min_probability=1e-2)

for variant in stream_variants("Open Source Marketing"):
    print(variant)

closure

Replicates lambda functions.

from OpenHosta import closure

is_masculine = closure("Is it a masculine name?")
print(is_masculine("John"))  # True

ask

A simple LLM call without OpenHosta's specific meta-prompt.

from OpenHosta import ask

print(ask("Do you know about scikit-learn?"))

Reasoning Models

For reasoning models (like DeepSeek-R1 or specific local models), OpenHosta automatically removes the reasoning part before casting the output.