For EU AI Engineering Teams · GDPR-native · Self-hosted

# LLM Observability
that stays in your cloud

Catch quality drops before users do, debug agent failures in seconds, and control costs — without prompts ever leaving your infrastructure.

Book a Demo See it live →

Self-hosted · MIT License · GDPR Article 28 ready · 2-line integration

import llm_observe
# Full setup. Nothing else needed.
llm_observe.init("https://agentlens.your-company.com")
llm_observe.patch_openai() # every call tracked automatically
The Problem

## You're flying blind

Every LLM app in production has the same three problems — and most teams don't notice until users complain.

🔥

### Silent quality drops

A prompt change tanks your output quality. You find out via user churn, not alerts.

💸

### Runaway costs

One bad loop in an agent burns $200 in 10 minutes. No one notices until the invoice arrives.

🕵️

### Agent black boxes

Your 5-step agent fails on step 3. Good luck figuring out which step, why, and how long it took.

🔒

### GDPR exposure

User prompts and outputs in a third-party SaaS. Legal says no. No audit trail either.

Solution

## Full visibility — self-hosted

Everything you need to understand, debug, and improve your LLM app. Your data stays on your server.

Core

### Auto Quality Scoring

Every response gets a 0–1 quality score automatically. Heuristic-based or powered by Claude as judge.

Core

### Hallucination Detection

Flags responses with confident-sounding false claims, repetition, refusals, and empty outputs.

Core

### Cost Tracking

Per-call cost calculated from token counts. Daily budget alerts via webhook or email before you overspend.

New v0.2

### Agent Debugger

Waterfall timeline of every agent step. See which span is slow, expensive, or failing — at a glance.

Core

### Regression Alerts

Compares current quality window vs previous. Alerts when quality drops more than your threshold.

Core

### GDPR Compliance

Export all data as JSON/CSV. Set retention policies. Delete by request ID. Full audit log.

Proof

## Real results from a production deployment

A 12-person legal tech team in Germany. AI contract analyzer. Three problems they couldn't solve with LangSmith or Helicone.

90%
faster agent debugging
€1,200
in API costs prevented
3 days → 90 min
to detect quality regressions
0
GDPR audit findings

"We had a prompt change tank quality by 22% on a Friday afternoon. We found out on Monday via support tickets. With AgentLens, we would have caught it in 90 minutes — automatically."

CTO · German Legal Tech SaaS · 12-person team
Read the full case study →
How we compare

## Built for teams that own their data

AgentLens is designed around one constraint: your LLM data never leaves your infrastructure. That shapes everything — from how it deploys to how it's priced.

Capability | AgentLens | LangSmith | Helicone
--- | --- | --- | ---
Self-hosted deployment | ✓ default | Enterprise plan only | Cloud only
EU data residency / GDPR DPA | ✓ Team plan+ | Enterprise plan only | Not available
Automatic quality scoring | ✓ zero config | Manual eval setup required | Not available
Hallucination detection | ✓ built-in | Not available | Not available
Agent waterfall debugger | ✓ | ✓ | Not available
2-line integration | ✓ | ✓ | ✓
Managed hosting — entry price | €299 / mo | from $39 / seat / mo | from $0 / mo (cloud)

Comparison based on publicly available information as of April 2026. Features and pricing may have changed — verify at langchain.com/pricing and helicone.ai/pricing. "Enterprise plan only" indicates the feature requires a paid enterprise contract with the respective vendor.

Detailed comparisons: AgentLens vs LangSmith · vs Langfuse · vs Helicone · vs Datadog LLM
Pricing

## Pricing that scales with your team

Self-host free forever. Upgrade for managed hosting, compliance packages, and dedicated support.

Starter
€299 / month
One team shipping one LLM product.

- Managed hosting (we run it)
- 1M calls / month
- 1 project
- Quality scoring + hallucination detection
- Agent debugger
- Email support (24h)
- Onboarding call included

Get Started →
Best for EU Teams
Team
€999 / month
For EU teams shipping LLM features that need GDPR-grade audit trails, not a SaaS in Virginia.

- Everything in Starter
- 10M calls / month
- 5 projects
- GDPR DPA (Art. 28) + AVV on request
- Data residency in EU (Frankfurt / Amsterdam)
- Audit log + compliance CSV exports
- Custom retention policies (delete after N days)
- Slack support + monthly review call
- 14-day trial, no credit card

Book a Demo →
Scale
€2.999 / month
Multiple products, dedicated deployment.

- Everything in Team
- 50M calls / month
- Unlimited projects
- Dedicated cloud instance (your region)
- 99.9% SLA
- Security package (pen test results)
- Custom integrations
- Dedicated Slack channel

Book a Demo →
Enterprise
€5.000+ / month
On-premise on your own cloud infrastructure.

- Deploy on AWS / GCP / Azure
- Unlimited calls & projects
- Data never leaves your VPC
- Custom SLA + dedicated engineer
- Invoice billing
- Security review + compliance audit
- Custom model support

Talk to Us →
Add-ons available on any plan: Extra projects (+€99/project/mo) · Extra call volume (+€49/1M calls) · Compliance report package (+€299/mo) · Priority SLA (+€199/mo)
Open Source forever: Self-host the full stack for free. MIT License. GitHub →

### See it live — no signup needed

The full dashboard is running with demo data. Click around, explore the Agent Debugger, try the filters.

Main Dashboard Agent Debugger Prompt Debugger Compliance

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