Tracing got you started. Simulation is what ships.

Beyond logging. Ship agents that actually work.

Langfuse is great at capturing what happened. LangWatch tests what your agent will do, before a single user touches it. Simulations, evaluations, observability, and prompt optimization in one platform that domain experts can use too.

Join thousands of AI developers shipping reliable agents with LangWatch.

simulation · ticket triage agent
run 1142
320ms
turn-01 · greet user
pass
540ms
turn-02 · classify intent
pass
1190ms
turn-03 · lookup_account()
pass
720ms
turn-04 · check policy
flag
410ms
turn-05 · escalation policy
pass
passed
4/5
latency
3.18s
judge
gpt-5
What Langfuse would have shown
trace5 spans, 1 error, 3.18s. Captured after the fact. The user already saw the wrong answer.
The Langfuse alternative.

How LangWatch compares to Langfuse.

Five things teams care about when picking a quality layer for agents. Each row shows what Langfuse ships today and what LangWatch gives you on day one.

01
Pre-production testing
Agent simulation suite

Scenario, the open-source simulation framework, runs thousands of multi-turn conversations with tools, persistent state, a virtual user, and a judge.

Basic evals on traces

Langfuse started as a tracing tool. Strong on capture, thin on agent-level testing before code hits production.

02
OpenTelemetry support
OTEL-native

OpenTelemetry is the first-class data model. Drop in any framework and trace lines map cleanly out of the box.

OTEL backend

Functions as an OTEL backend but requires manual property mapping for trace visualization to line up.

03
Who can use it
Devs, PMs, and domain experts

Scenarios in code or in the UI. Quality gates that legal, support, and product can read and edit.

Developer-only

Built for devs. Onboarding non-technical stakeholders into the loop is heavy lifting.

04
Prompt optimization
DSPy-native, GitHub-synced

Automated optimization with MIPROv2, ChainOfThought, and few-shot, version controlled alongside the rest of your repo.

Manual prompt registry

Prompt management exists, but optimization is on you to drive iteration cycle by cycle.

05
Analytics that move the business
Technical + product analytics

Traces, cost, latency next to funnels, session patterns, and conversion. One view for AI quality and AI outcomes.

Technical metrics only

Strong on trace analysis and cost, light on user behavior and product analytics for the agent itself.

Three reasons agent teams choose LangWatch.

sim · turn-01turn-12 · pass
Agent simulations, enterprise grade

Multi-step workflows, tool calls, and multi-modal flows tested against realistic scenarios. Release confidence, not crossed fingers.

prompt v1 → v4 → v8 · score 0.91
DSPy-native optimization

Systematic generation, scoring, and selection of prompt variants. Real algorithmic optimization, not yet another diff viewer.

scenarios.pyscenario.run( agent=triage,)UI builder
A platform for the whole team

Domain experts design scenarios in the UI. Engineers build workflows in code. Both edit the same source of truth.

It felt like ML evals from the classic era, but built for agents. We finally had a way to ship without holding our breath.
Head of AI · Enterprise B2B customer support team
94%
regressions caught pre-prod
5 min
time-to-first-eval
any
frameworks supported
$0
cost to start

Ship agents with confidence, not crossed fingers.

Connect in five minutes. Any framework, any model. Agent simulation included on day one.