Full Agent simulation testing suite
Scenario-based testing framework that simulates real user interactions to validate complex agent behaviors and multi-step workflows before they reach production environments.
Eval library +
Strong pre-built Evaluations. LangWatch eval quality is one of its strongest features of the platform. Whether you run Evals via code or run experiments online and offline via the platform
Open source + Self-Hosted availability
Full platform is open source. Audit every component. Zero vendor lock-in at any tier.
Flexible collaboration model
Friendly platform UI for domain experts to create scenarios while providing powerful APIs and SDKs for developers to build complex workflows.
Voice-native simulation
Full STT → LLM → TTS pipeline simulation with real audio in and out. Unique in the LLMOps category.
Not available
Braintrust generates eval datasets from existing traces. No pre-production simulation with tools, state, or virtual user
Auto-evals
Braintrust has a pretty strong Evaluation section in there platform, predominantly used by developers, who come to LangWatch when they want to hand it over to less technical people
Proprietary SaaS
Closed codebase. You cannot inspect what processes your trace data or how it is stored.
Technical team focus
Built for engineers. Human review queues exist but non-technical stakeholders have no real seat at the quality table.
Not Available
Text-only platform. Teams building voice AI products have no testing path in Braintrust.
LangWatch lets you run thousands of realistic, multi-turn conversations against your full agent stack tools, persistent state, a configurable virtual user, and a judge before a single real user interaction happens. You catch hallucinations, tool failures, reasoning drift, and out-of-policy behavior in a safe sandbox.
Stop scoring failures. Start preventing them.
LangWatch is free to start. Connect in minutes — any framework, any LLM provider. Agent simulation included on day one.
