Opper
Swedish EU-hosted AI gateway with logs, span-level traces and per-call checks
Quick Overview
| Company | Opper Technology AB |
|---|---|
| Category | LLM Observability and Evaluation Tools |
| Headquarters | Sweden, Sweden |
| Founded | Not stated |
| EU Presence | Yes - Sweden (EU) |
| Data Location | EU-hosted API with EU routes; zero data retention by default |
| Open Source | No |
| GDPR Compliant | Yes |
| Self-Hosting | No |
| Main Features | 700+ models, EU enforcement, call logs, traces and span tree, trace replay, custom spans, events and feedback, rules, flag/redact/block/score checks |
| Pricing | Pay as you go: 3% platform fee (Gateway), 5.5% (Control Plane); Enterprise custom |
| Best For | Teams that want an EU gateway first and basic trace debugging with it |
| Replaces | Helicone, LangSmith (tracing only) |
Detailed Review
Opper is an AI gateway first. Its documentation has an Observe and Control section where every call is logged, and tracing records a tree of spans for model calls, tool calls and the rules that fired. A trace can be replayed in the playground and custom spans can be added.
The terms name Opper Technology AB, registered in Sweden under organisation number 559446-3720. By default calls are logged as metadata only and inputs and outputs are not stored.
Logs and traces
Logs list every provider call with model, provider, status, tokens, cost, latency and region. Without a retention rule Opper records usage metadata but does not store traces, so storing inputs, outputs and spans is a deliberate setting.
Checks and rules
Pricing lists LLM checks that flag, redact, block or score a call, billed at a flat rate per check on top of the platform fee. Control Plane adds org budgets, role-based limits and rules.
Pricing
Gateway is pay as you go with a 3% platform fee, Control Plane 5.5%, both with 700+ models from 50+ providers. Full traces with 1 to 30 days of retention are listed under Control Plane.
Limitations to Consider
Opper is not an evaluation workspace: the pages checked show traces, logs and scoring checks but no dataset or experiment tooling, so it complements rather than replaces Giskard or Galtea. Storing traces needs a retention rule and the Control Plane tier. It is proprietary and has no self-hosted edition.
Who Should Use Opper
Teams that want an EU-operated gateway with zero data retention routes and enough tracing to debug agent calls.
Pros and Cons
Pros
- EU-hosted gateway under a Swedish company
- Span-level traces with replay
- Zero data retention by default
- Per-call flag, redact, block or score checks
- Pay as you go
Cons
- Gateway-first, limited evaluation tooling
- Traces need a retention rule and Control Plane
- Percentage fee on model spend
- No self-hosted edition
Alternatives to Opper
Other European llm observability and evaluation tools worth comparing before you decide:
LangWatch
Netherlands · Open-source agent tracing, evaluations and simulations from Amsterdam
Latitude
Spain · Open-source agent observability that groups failures into issues
Galtea
Spain · Test generation, simulation and evaluation for regulated industries
Giskard
France · Red teaming and evaluation for LLM agents before release
See all European llm observability and evaluation tools or compare them directly against Helicone on our alternatives page.
Frequently Asked Questions
By default calls are logged as metadata only; inputs and outputs appear only when a retention rule stores them.
Yes. The documentation describes traces as a tree of spans, with a trace explorer, span tree, replay in the playground and custom spans.
The pricing page lists a 3% platform fee for Gateway and 5.5% for Control Plane, with Enterprise on a custom contract.