Developer plan is free for solo users with up to 5k base traces per month, then pay-as-you-go. Plus plan costs $39/seat/month with 10k base traces included. Enterprise plan offers custom pricing with advanced options.
Not given
Key features
Agent observability with step-by-step tracing
Agent evaluation and scoring
Agent deployment infrastructure
Production monitoring with online evaluations
Autonomous agent improvement with Engine
Secure sandbox execution for agent-generated code
LLM Gateway for model call control
No-code agent builder Fleet
Open source frameworks for agent development
Hierarchical traces capture every LLM call, tool invocation, and retrieval step
LLM-as-a-judge, heuristic functions, or human review evaluations
Prompt management with one-click deployments and rollbacks
Playground to test prompts on real production inputs and compare models
Experiments with test cases and side-by-side comparison
Human annotation and collaborative human-in-the-loop workflows
Cost and latency monitoring with dashboards and alerts
REST APIs and Query SDK for data access
Langfuse Assistant to automate the AI engineering loop
What makes it different
Comprehensive platform covering the entire agent development lifecycle from building to monitoring
Open source frameworks with options from quick-start to low-level control
Built-in observability and evaluation capabilities integrated into the platform
Support for long-running autonomous agents with Deep Agents framework
MIT licensed open source platform with no data lock-in
Enterprise scale architecture handling billions of monthly events
Works with any language and framework with no framework lock-in
Async by default so tracing never blocks your application