Welcome to Opper

The European AI gateway for agents. 700+ models from 50+ providers through one EU-hosted API. Drop-in OpenAI, Anthropic, and Google AI SDK compatible. GDPR-compliant.

Opper is one API in front of every major AI model, hosted in the EU. Drop in your existing OpenAI, Anthropic, or Google AI SDK and keep your code — you get text, multimodal, and voice, plus observability, governance, and one sub-processor for every model. Not writing code? Point an app you already use, like Claude Code or Cursor, at Opper instead — see Integrations.

Agent Assisted Development

Use curl to download, read and follow: https://skills.opper.ai

Paste this into your coding agent — Claude Code, Cursor, Codex, and more — and it will set up and build with Opper for you.

Start here

Quickstart

Five minutes to your first call.

What is Opper?

The product tour: Gateway, Rules, traces, and how they fit.

AI Gateway

One API, 700+ models, routing, and EU enforcement.

Security

Hosted in Stockholm. One sub-processor for every model. No prompts or responses stored by default.

Build

Drop-in SDKs

Use the OpenAI, Anthropic, or Google AI SDK you already have.

Structured output

Constrain any response to a JSON Schema. Great for parsing and extraction.

Realtime

Two-way voice over WebSocket. OpenAI, xAI, and Gemini behind one protocol.

Models

The full catalog. EU-hosted models marked.

Govern and improve

Observe & Control

Inspect calls and manage the rules Opper enforces.

Rules

Set budgets, model access, retention, and routing, enforced at the gateway.

Checks

Score every response against criteria you write.

Concepts

Gateway, projects, Rules, and what happens on a call.