Introduction
What the Nebul Inference API is, what you can call, and where to start
The Nebul Inference API serves open-weight models over an OpenAI-compatible REST API at https://api.inference.nebul.io/v1. If your code talks to OpenAI, point it at Nebul, swap the key and model ID, and it runs: chat, reasoning, vision, embeddings, audio, and image generation, on GPU clusters in EU data centers. Your data never trains the models; see Privacy & Security.
Requests are billed per token in EUR. Every model's input and output price, context window, and capability flags are listed in the Model Catalog.
Make a request now
Create an API key in Nebul AI Studio and export it:
export NEBUL_API_KEY="sk-your-key"import os
from openai import OpenAI
client = OpenAI(
api_key=os.environ["NEBUL_API_KEY"],
base_url="https://api.inference.nebul.io/v1",
)
response = client.chat.completions.create(
model="zai-org/GLM-5.3",
messages=[{"role": "user", "content": "Say OK"}],
)
print(response.choices[0].message.content)You should see the model's answer to your message. The Quick Start covers key setup and the first request in eight languages; the SDKs page has the same setup for Python, TypeScript, JavaScript, Go, Rust, Java, C++, and the shell.
What you can call
| Capability | Endpoints | Guide |
|---|---|---|
| Chat, reasoning, vision, tools, structured output | /v1/chat/completions, /v1/responses, /v1/messages | Chat Completions, Responses, Messages |
| Embeddings and reranking | /v1/embeddings, /v1/rerank | Embeddings, Reranking |
| Speech to text, text to speech | /v1/audio/transcriptions, /v1/audio/speech | Speech to Text, Text to Speech |
| Image generation and editing | /v1/images/* | Image Models |
| OCR | /v1/ocr | OCR |
| Files for prompts and fine-tuning | /v1/files | Files API |
Everything speaks OpenAI-shaped JSON, so the official OpenAI SDKs work with a two-line change. /v1/messages is the exception: it speaks the Anthropic Messages format, so the Anthropic SDKs work against it directly. See SDKs for both.
Where to go next
- Quick Start: key setup, first request in your language, full endpoint list
- Examples: streaming, vision, tools, and reasoning code
- Model Catalog: every model with pricing, context windows, and capability flags
- Errors: status codes, response shapes, and retry rules
- API Reference: full OpenAPI specification