LangSmith Alternative · Self-hosted · MIT Licensed

# AgentLens vs LangSmith
Same visibility. Your infrastructure.

LangSmith is powerful — but self-hosting is locked behind Enterprise, and every prompt your users send flows through LangChain's US cloud. AgentLens gives you the same tracing, evals, and agent debugging, self-hosted by default.

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Quick Comparison

## Feature-by-feature

Capability | AgentLens | LangSmith
--- | --- | ---
Self-hosted (free tier) | ✓ default, MIT | Enterprise plan only
EU data residency / GDPR DPA | ✓ Team+ plan | Enterprise plan only
Automatic quality scoring | ✓ zero config | Manual eval setup
Hallucination detection | ✓ built-in | ✗
Agent waterfall debugger | ✓ | ✓
Framework-agnostic SDK | ✓ any Python | LangChain-native
Cost tracking + budget alerts | ✓ | ✓
2-line integration | ✓ | ✓
Starting price (managed) | €299 / mo flat | $39 / seat / mo + usage
Starting price (self-hosted) | Free (MIT) | Enterprise contract

Based on public LangSmith pricing as of April 2026. Verify at langchain.com/pricing.

When to choose what

## Honest recommendation

### Choose LangSmith if…

- Your team is deeply invested in the LangChain ecosystem
- You're fine with data flowing through US cloud
- You have budget for Enterprise self-hosting (~$5k+/mo)
- You need tight coupling with LangChain Hub + LangGraph tooling

### Choose AgentLens if…

- Your prompts contain user data that can't leave EU / your VPC
- You want self-hosting without a 5-figure contract
- You want quality scoring + hallucination detection out of the box
- You use multiple frameworks (LangChain + raw OpenAI + custom)
- You want flat pricing — no per-seat billing

Migration

## Switching from LangSmith takes ~30 minutes

Both tools use a decorator/patch model. The SDK surface is different, but the migration is mechanical.

# Before (LangSmith)
import os
os.environ["LANGCHAIN_TRACING_V2"] = "true"
os.environ["LANGCHAIN_API_KEY"] = "..."
# After (AgentLens)
import llm_observe
llm_observe.init("https://agentlens.your-company.com")
llm_observe.patch_openai() # or patch_anthropic()
FAQ

## Common questions

Is AgentLens a drop-in LangSmith replacement?

Not API-compatible — but the mental model (traces, spans, evals) is identical and the dashboard is familiar. Most teams migrate in under an hour.

Can I self-host LangSmith?

LangSmith self-hosting is restricted to LangChain's Enterprise plan. AgentLens is self-hosted by default and MIT licensed — you can run it on a €5 VPS.

Does AgentLens work without LangChain?

Yes. Framework-agnostic. Works with plain OpenAI/Anthropic SDKs, LangChain, LlamaIndex, CrewAI, AutoGen, and custom agents.

How much does AgentLens cost compared to LangSmith?

LangSmith Plus starts at $39/seat/month plus usage. AgentLens Starter is €299/month flat for 1M calls (no seat limits), or free when self-hosted.

Is there a GDPR DPA available?

Yes, included on Team plan (€999/mo) and above. LangSmith's DPA is Enterprise-tier only.

### Ready to own your LLM data?

15-minute migration call. We'll map your LangSmith setup to AgentLens and get you running.

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