aster-work: $0.40 input / $0.80 output per million tokens. aster-code: $0.80 input / $1.60 output per million tokens. No subscription or seat fees. Prepaid credits start at $5 with no expiry. Routing included in product rates.
Key features
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
Task-aware model routing
Curated model collection
What makes it different
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
Reinforcement learning router trained on real task data