Guide, updated Oct 16, 2026
Best observability and eval tools for AI agents
Tracing, debugging, and evals for agents in production. We list 5 observability and eval tools, 2 open source. Summaries come from each vendor's own site and every link was checked on or before Oct 16, 2026.
Shortlist
All 5 at a glance
Alphabetical. Nothing in this guide is a paid placement.
| Tool | What it does | Open source | More |
|---|---|---|---|
| AgentOps | Tracing and debugging for AI agents. | No | Alternatives |
| Braintrust | Observability and evals platform for production agents. | No | Alternatives |
| Helicone | AI gateway with routing and LLM observability. | Yes | Alternatives |
| Langfuse | Open-source tracing, evals, and observability for agents. | Yes | Alternatives |
| LangSmith | LangChain's tracing and monitoring platform for agents and LLM apps. | No | Alternatives |
How to choose
What to check before you pick
- Tracing depth: full agent runs with tool calls, not just single LLM calls.
- Evals: offline test sets, online scoring, and human review.
- Hosting: open source and self-hostable, or managed only.
- Integrations: OpenTelemetry and your agent framework.
- Pricing unit: per trace, per event or per seat. Check each vendor's pricing page.
This checklist is general advice. Check each vendor's docs and pricing page for current details.
The tools
Each option in one paragraph
AgentOps
agentops.aiTracing and debugging for AI agents.
In their words: “AgentOps”
Braintrust
braintrust.devObservability and evals platform for production agents.
In their words: “Braintrust - The active observability platform for agents”
Helicone
helicone.aiAI gateway with routing and LLM observability.
In their words: “Helicone / AI Gateway & LLM Observability”
Langfuse
langfuse.comOpen-source tracing, evals, and observability for agents.
In their words: “Langfuse: Open Source Agent Evals & Observability”
LangSmith
langchain.comLangChain's tracing and monitoring platform for agents and LLM apps.
In their words: “LangSmith: Agent & LLM Observability Platform”
Head to head
Compare them side by side
FAQ
Questions
Which observability and eval tools does Agent Stack Directory list?
5: AgentOps, Braintrust, Helicone, Langfuse, LangSmith.
Which of them are open source?
Helicone, Langfuse are marked open source in our data.
How is this list ordered?
Alphabetically. No placement in this guide is paid. Sponsored and featured tools are labeled elsewhere on the site and never reordered here.
More guides:Best cloud browsers for AI agentsBest code sandboxes for AI agentsBest memory layers for AI agentsBest search and web data APIs for AI agentsBest email APIs for AI agentsBest tool integration platforms for AI agentsBest payment tools for AI agentsBest voice agent platformsBest AI agent frameworksBest open-source infrastructure for AI agents