> ## Documentation Index > Fetch the complete documentation index at: https://docs.perceptron.inc/llms.txt > Use this file to discover all available pages before exploring further. # Python SDK FAQs > Answers to the most common questions about Perceptron’s Python client. ## What model name should I use? Use `model="perceptron-mk1"` for Perceptron's flagship vision-language model — supports image and video inputs, reasoning, and structured annotations (point, box, polygon, clip). Set `provider="perceptron"`. For lighter-weight image-only variants (single-image or multi-image understanding), drop to the 0.2 series: `model="isaac-0.2-2b-preview"` for the standard 2B reasoning model or `model="isaac-0.2-1b"` for the compact edge-deployable 1B. The legacy `model="isaac-0.1"` is still supported for existing integrations. ## Do I have to self-host? No. The hosted API is the fastest way to ship. Self-hosting is optional for the 0.x series — pull the [isaac-0.2-2b-preview weights](https://huggingface.co/PerceptronAI/Isaac-0.2-2B-Preview), the [isaac-0.2-1b weights](https://huggingface.co/PerceptronAI/Isaac-0.2-1B), or the [isaac-0.1 weights](https://huggingface.co/PerceptronAI/Isaac-0.1) if you need to deploy on-prem or at the edge. Perceptron Mk1 is hosted-only. ## How do I stream partial results? Use the `stream=True` flag (or the `perceptron.question` helper) to receive `text.delta` and `points.delta` events as the model reasons. ## Why am I getting `AuthError`? The SDK found no usable API key. Double-check that `PERCEPTRON_API_KEY` is set before running your script, or pass `configure(api_key="sk-live-...")` inline. If you use `.env`, call `load_dotenv()` before invoking `configure`. Still stuck? [Contact support](mailto:support@perceptron.inc) with logs or share a repro in our Discord.