LangWatch
Open-source agent testing and observability built around the Scenario simulation framework, covering text, voice and adversarial tests.
| Category | Evals & Testing |
| Open source | Yes |
| Self-hostable | Yes |
| Pricing model | freemium |
| Pricing notes | OSS self-host; cloud free tier + paid plans |
| Framework integrations | openai-sdk, langchain, dspy, opentelemetry, vercel-ai |
| Funding / ownership | Netherlands-based; seed stage |
| GitHub stars | 3,299 |
| Maintenance | active (commit 2026-06-13) |
| License (GitHub) | Apache-2.0 |
| Open issues | 721 |
| Maturity signal | 93/100 (Mature) — computed from public GitHub signals, see methodology |
Pricing/feature source: https://langwatch.ai/pricing
Maturity signal is computed from public GitHub data only. How it is calculated.
Frequently asked questions
Is LangWatch open source?
Yes. Licensed under Apache-2.0.
Can I self-host LangWatch?
Yes — LangWatch can run in your own infrastructure.
How much does LangWatch cost?
Freemium. OSS self-host; cloud free tier + paid plans