LLM Gateway

Switch between AI models in one line of code

The EU-hosted LLM gateway for production AI. Access 300+ AI models through one API with instant switching, automatic fallbacks, and cost optimization. No vendor lock-in.

Your App

// OpenAI SDK compatible
const res = await client
.chat.completions
.create({
model: "anthropic/claude-sonnet-4.6"
});

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Challenge

Why is managing multiple AI providers so hard?

Direct model integrations lock you into single providers with no failover, waste budget on expensive models for simple tasks, and can't adapt to regional compliance needs.

Vendor Lock-in

Hard-coded model providers make it impossible to switch when better models emerge or when you need regional compliance.

No Fallback Strategy

A single API outage or rate limit can bring your entire application down. No built-in redundancy means lost revenue.

Cost Inefficiency

Using expensive flagship models for simple tasks wastes budget. No easy way to route different workloads to cost-optimal models.

Regional Limitations

Data sovereignty requirements force complex infrastructure. Can't easily use EU-hosted models when needed for compliance.

The Opper Way

One API. Every model. Zero lock-in.

Build once, run anywhere with intelligent model routing

Instant model switching

The Opper LLM router switches between 300+ models with one line of code. Test OpenAI, Anthropic, Google, and others without rewriting your application. Deploy the best model for each task.

  • Zero downtime
  • 300+ models
Browse all 300+ models
from openai import OpenAI

client = OpenAI(
  base_url="https://api.opper.ai/v3/compat",
  api_key=OPPER_API_KEY,
)

response = client.chat.completions.create(
  model="openai/gpt-4o-mini",
  messages=[...]
)

# Same SDK, 300+ models, automatic fallbacks

Automatic fallbacks

Configure backup models that activate instantly if your primary fails. Built-in retry logic and error handling keep your application running through outages and rate limits.

  • 99.9% uptime guarantee
  • Zero config required
See our JSON API with structured retries
claude-sonnet-4.5
AWS Bedrock
Timeout
Auto-retry in 180ms
claude-sonnet-4.5
Anthropic Direct
Success
Total latency: 0.9s

Cost optimization

Route simple tasks to fast, cheap models and complex ones to premium models. Track spend per model and optimize your AI budget automatically.

  • Intelligent routing by complexity
  • Real-time cost tracking
75%avg. cost reduction
Simple queries (80%)
gemini-2.5-flash
$0.30/1M input tokens
Complex queries (20%)
gpt-5
$1.25/1M input tokens

Regional compliance

Access EU-hosted models from AWS, Azure, GCP, and providers like Berget AI for GDPR compliance. Switch regions as easily as switching models.

  • GDPR-compliant EU data centers
  • One-line region switching
Same models, different regions:
US Region
claude-sonnet-4.5
Anthropic
EU Region
claude-sonnet-4.5
AWS Bedrock
US Region
gpt-5
OpenAI
EU Region
gpt-5
Azure

Full audit trail

Every call logged. Every token tracked. Every dollar accounted for. Searchable logs for every model interaction with user attribution, cost breakdowns, and policy enforcement — ready for SOC 2, GDPR, and internal audits.

  • Complete request and response logging
  • Export-ready compliance reports
See full observability features
claude-sonnet-4.6
2.3s · 1,847 tokens
User: felix@acme.comCost: $0.0092Region: EU
gpt-5
1.8s · 2,104 tokens
User: sara@acme.comCost: $0.0263Region: EU
gpt-5
PII blocked
User: dev@acme.comPolicy: no-pii-euRegion: EU
Showing 3 of 12,847 events today

Model catalog & pricing

Access the latest AI models from leading providers with unified pricing per million tokens.

All prices are per 1M tokens • EU and US regions available • Prices subject to change, see docs for latest

ProviderModelRegionInput (1M tokens)Output (1M tokens)
Loading models...

Custom Models & BYOK

Bring your own API keys or add custom model deployments using the Opper CLI or API.

opper models create example/my-gpt5 azure/gpt5-production YOUR_API_KEY

Looking for a specific model? View complete model list →

FAQ

LLM gateway & AI gateway FAQ

What is an LLM gateway?

+
An LLM gateway is a unified API layer that routes requests across multiple large language model providers. It handles authentication, rate limiting, fallbacks, cost optimization, and audit logging — so your application can switch between OpenAI, Anthropic, Google, and others without rewriting code. Opper's LLM gateway is OpenAI SDK-compatible and routes across 300+ models, with EU-hosted regions on AWS Bedrock, Azure, GCP, and Berget AI.

Is an LLM gateway the same as an AI gateway?

+
Closely related but not identical. LLM gateways focus on text models (chat, completions, embeddings). AI gateways extend the same architecture to multimodal workloads — image generation, voice, video, and other AI APIs. Most production AI gateways today are primarily LLM gateways with multimodal support added. Opper covers both: text, image, voice, and video models through one OpenAI-compatible API.

How does Opper's gateway handle model fallbacks?

+
Configure backup models that activate instantly if your primary fails. Built-in retry logic detects timeouts, rate limits, and provider outages, then routes the request to your configured fallback within roughly 180ms. Zero downtime, no code changes, no extra infrastructure to run.

Is Opper's LLM gateway EU-hosted and GDPR-compliant?

+
Yes. Opper's control plane runs in the EU by default, and the LLM gateway can pin every request to EU regions on AWS Bedrock, Azure, GCP, or providers like Berget AI. Audit logs and traces stay in EU storage. GDPR-ready, with a DPA and sub-processor list published.

How is Opper's LLM gateway different from OpenRouter, Vercel AI Gateway, or Cloudflare AI Gateway?

+
OpenRouter and Vercel/Cloudflare AI Gateways are inference routers — they switch models. Opper does that, plus adds the layers production deployments need: built-in observability with LLM-as-a-judge scoring, a structured-output JSON API, guardrails, EU residency by default, and pay-as-you-go pricing with no subscription. Think of it as a router with an AI agent control plane built in.
How GetTested delivers personalized health insights

Case Study

How GetTested delivers personalized health insights

GetTested uses Opper's LLM Gateway to translate biomarker data into personalized health recommendations at scale — serving 10,000+ customers monthly across 60 countries with reliable, fact-checked AI insights.

Ready to access 300+ AI models?

Start building with flexible model routing today

Get startedBrowse models