langfuse alternatives

Langfuse, AgentOps and Helicone record and trace what your agents did, so they suit teams that debug prompts and review cost after the fact. Stopping a run before it overspends takes something in the request path, which is what a proxy like RelayPlane does, and many teams run both.

We make RelayPlane, a free open source proxy that caps agent spend, so we say where the other options fit better.

How we compared them

People search for Langfuse alternatives for different reasons: a different price, a different hosting model, or a gap in what it does. We used four criteria, in the words below, and we judge each option on them for a named type of buyer.

  • Where it sits, meaning whether it records what happened after the call or sits in the request path and can refuse a call.
  • Cost model, meaning what the free tier covers and what a paid plan costs, from the vendor page.
  • Hosting and lock-in, meaning whether it is open source, self-hostable, and how much code you change to adopt it.
  • Spend control, meaning whether it only tracks spend or can also stop a run that is overspending.

Every fact about another company below comes from a page we fetched on 2026-10-07, linked in the Sources section. Opinions are marked as ours.

Langfuse, the baseline

Langfuse is an open source LLM engineering platform. It helps teams collaboratively develop, monitor, evaluate, and debug AI applications. It also manages prompts and runs evaluations, so its scope is wider than cost.

On cost, its pricing page lists a free Hobby plan with 50k units / month included, and a Core plan at $29 / month with 100k units / month included, additional: $8/100k units. You can use Langfuse Cloud or self-host it, and the README says it can be self-hosted in minutes with Docker Compose.

The drawback for this search: it traces and counts. In our view it is a record of what happened, not a gate on the next request. You instrument your app, then read the result.

AgentOps

AgentOps helps developers build, evaluate, and monitor AI agents. Its README lists step by step agent execution graphs for replay and debugging, and cost management that lets you track spend with LLM foundation model providers. The AgentOps app is open source under the MIT license, and the README says you can self-host the dashboard and API backend.

It fits teams building multi-agent systems in Python who want session replay. The README lists native integrations with CrewAI, AG2 (AutoGen), Agno, LangGraph, and more. The adoption path is an SDK: you add pip install agentops and initialize it in your program. We read its spend feature as tracking. We did not find a per-run limit on the pages we fetched, so check its docs if you need one. See also our AgentOps comparison.

Helicone

Helicone describes itself as an AI Gateway and LLM Observability Platform for AI Engineers. You change the base URL in your OpenAI client, and the README says you can access 100+ AI models with 1 API key. That makes it the closest option to a proxy on this list, and the right pick if a hosted gateway with logging in one product is what you want.

The README mentions a generous monthly free tier (10k requests/month), and the pricing page lists a Hobby plan with 10,000 free requests and a Pro plan at $79 per month. It can be self-hosted with Docker, though the README calls manual deployment not recommended. Read the Helicone comparison for the details we have on it.

RelayPlane, a proxy that caps spend

RelayPlane is not an observability suite. It is a free, open source (MIT) proxy that runs on your own machine, meters what each agent run costs, and reacts when a limit is hit by blocking, downgrading or warning, per the budget cap docs. The cap is checked before a request is forwarded, so the request that would cross the limit is the one that gets stopped.

It will not replace Langfuse for prompt management, datasets or evaluation. If you want those, keep Langfuse and put a proxy in front of your agents. The tradeoff is that you route traffic through a local process, which is one more moving part. The docs give this command for a daily cap.

relayplane cap set --day 10

For a single job, the per-task cap guide shows the run header. The LLM proxy page covers installing it, and the Langfuse comparison sets the two side by side.

Which fits whom

We do not rank these, because they answer different questions. In our view, a team working on prompts and output quality should stay with Langfuse, or look at AgentOps if session replay for agent frameworks is the pull. A team that wants a hosted gateway with logging in one product should look at Helicone.

A team whose worry is a runaway loop on the monthly bill needs a hard stop, and that is a proxy such as RelayPlane, run next to whichever tracer you already use.

Sources

Vendor prices and features change. Check the linked page before you decide.