zenllm 0.2.0

A zen, simple, and unified API to prompt LLMs from Anthropic, Google, OpenAI, and more, using only the requests library.

🧘‍♂️ ZenLLM

The zen, simple, and unified API for LLMs with the best developer experience: two ergonomic entry points and one consistent return type.

Philosophy: No SDK bloat. Just requests and your API keys. Multimodal in and out. Streaming that’s easy to consume.

✨ What’s new (breaking change)

• Two functions: generate() for single-turn, chat() for multi-turn.
• Simple inputs for 95% cases. Escape hatch for advanced parts remains.
• Always returns a structured Response (or a ResponseStream when streaming).
• Image outputs are first-class (bytes or URLs), not lost in translation.

🚀 Installation

pip install zenllm

💡 Quick start

First, set your provider’s API key (e.g., export OPENAI_API_KEY="your-key").

You can also set a default model via environment:

• export ZENLLM_DEFAULT_MODEL="gpt-4.1"

Text-only

import zenllm as llm

resp = llm.generate("Why is the sky blue?", model="gpt-4.1")
print(resp.text)

Vision (single image shortcut)

import zenllm as llm

resp = llm.generate(
    "What is in this photo?",
    model="gemini-2.5-pro",
    image="cheeseburger.jpg",  # path, URL, bytes, or file-like accepted
)
print(resp.text)

Vision (image generation output)

Gemini can return image data inline. Save them with one call.

import zenllm as llm

resp = llm.generate(
    "Create a picture of a nano banana dish in a fancy restaurant with a Gemini theme",
    model="gemini-2.5-flash-image-preview",
)
resp.save_images(prefix="banana_")  # writes banana_0.png, ...

Multi-turn chat with shorthands

import zenllm as llm

resp = llm.chat(
    [
      ("system", "Be concise."),
      ("user", "Describe this image in one sentence.", "cheeseburger.jpg"),
    ],
    model="claude-sonnet-4-20250514",
)
print(resp.text)

Streaming with typed events

import zenllm as llm

stream = llm.generate(
    "Generate an image and a short caption.",
    model="gemini-2.5-flash-image-preview",
    stream=True,
)

caption = []
for ev in stream:
    if ev.type == "text":
        caption.append(ev.text)
        print(ev.text, end="", flush=True)
    elif ev.type == "image":
        if getattr(ev, "bytes", None):
            with open("out.png", "wb") as f:
                f.write(ev.bytes)
        elif getattr(ev, "url", None):
            print(f"\nImage available at: {ev.url}")
final = stream.finalize()  # Response

Using OpenAI-compatible endpoints

Works with local or third-party OpenAI-compatible APIs by passing base_url.

import zenllm as llm

# Local model (e.g., Ollama or LM Studio)
resp = llm.generate(
    "Why is the sky blue?",
    model="qwen3:30b",
    base_url="http://localhost:11434/v1",
)
print(resp.text)

# Streaming
stream = llm.generate(
    "Tell me a story.",
    model="qwen3:30b",
    base_url="http://localhost:11434/v1",
    stream=True,
)
for ev in stream:
    if ev.type == "text":
        print(ev.text, end="", flush=True)

🧱 API overview

• generate(prompt=None, *, model=..., system=None, image=None, images=None, stream=False, options=None, provider=None, base_url=None, api_key=None)
• chat(messages, *, model=..., system=None, stream=False, options=None, provider=None, base_url=None, api_key=None)

Inputs:

• prompt: str
• image: single image source (path, URL, bytes, file-like)
• images: list of image sources (same kinds)
• messages shorthands:
  • "hello"
  • ("user"|"assistant"|"system", text[, images])
  • {"role":"user","text":"...", "images":[...]}
  • {"role":"user","parts":[...]} // escape hatch for experts
• options: normalized tuning and passthrough, e.g. {"temperature": 0.7, "max_tokens": 512}. These are mapped per provider where needed.

Helpers (escape hatch):

• zenllm.text(value) -> {"type":"text","text": "..."}
• zenllm.image(source[, mime, detail]) -> {"type":"image","source":{"kind": "...","value": ...}, ...}

Outputs:

• Always a Response object with:
  • response.text: concatenated text
  • response.parts: normalized parts
    • {"type":"text","text":"..."}
    • {"type":"image","source":{"kind":"bytes"|"url","value":...},"mime":"image/png"}
  • response.images: convenience filtered list
  • response.finish_reason, response.usage, response.raw
  • response.save_images(dir=".", prefix="img_")
  • response.to_dict() for JSON-safe structure (bytes are base64, kind becomes "bytes_b64")

Streaming:

• Returns a ResponseStream. Iterate events:
  • Text events: ev.type == "text", ev.text
  • Image events: ev.type == "image", either ev.bytes (with ev.mime) or ev.url
• Call stream.finalize() to materialize a Response from the streamed events.

Provider selection:

• Automatic by model prefix: gpt, gemini, claude, deepseek, together
• Override with provider="gpt"|"openai"|"openai-compatible"|"gemini"|"claude"|"deepseek"|"together"
• OpenAI-compatible: pass base_url (and optional api_key) and we append /chat/completions

✅ Supported Providers

Provider	Env Var	Prefix	Notes	Example Models
Anthropic	ANTHROPIC_API_KEY	claude	Text + Images (input via base64)	claude-sonnet-4-20250514, claude-opus-4-20250514
DeepSeek	DEEPSEEK_API_KEY	deepseek	OpenAI-compatible; image support may vary	deepseek-chat, deepseek-reasoner
Google	GEMINI_API_KEY	gemini	Text + Images (inline_data base64)	gemini-2.5-pro, gemini-2.5-flash
OpenAI	OPENAI_API_KEY	gpt	Text + Images (image_url, supports data URLs)	gpt-4.1, gpt-4o
TogetherAI	TOGETHER_API_KEY	together	OpenAI-compatible; image support may vary	together/meta-llama/Meta-Llama-3.1-8B-Instruct-Turbo

Notes:

• For OpenAI-compatible endpoints (like local models), pass base_url and optional api_key. We’ll route via the OpenAI-compatible provider and append /chat/completions.
• Some third-party endpoints don’t support vision. If you pass images to an unsupported model, the upstream provider may return an error.
• DeepSeek and Together may not accept image URLs; prefer path/bytes/file for images with those providers.

🧪 Advanced examples

Manual parts with helpers:

from zenllm import text, image
import zenllm as llm

msgs = [
  {"role": "user", "parts": [
    text("Describe this in one sentence."),
    image("cheeseburger.jpg", detail="high"),
  ]},
]
resp = llm.chat(msgs, model="gemini-2.5-pro")
print(resp.text)

Provider override:

import zenllm as llm

resp = llm.generate(
  "Hello!",
  model="gpt-4.1",
  provider="openai",  # or "gpt", "openai-compatible", "gemini", "claude", "deepseek", "together"
)
print(resp.text)

Serialization:

d = resp.to_dict()  # bytes are base64-encoded with kind "bytes_b64"

📜 License

MIT License — Copyright (c) 2025 Koen van Eijk