LangWatch

LangWatch belongs in the catalog because it addresses a broader quality workflow than simple tracing alone. The official site positions it around traces, evaluations, agent simulations, prompt management, prompt optimization, and collaborative debugging for agentic systems. That makes it especially relevant for teams who want one platform to move from production traces into test cases, experiments, and release gating instead of stitching together separate tools for each layer.

It also deserves inclusion because the official pricing page is specific enough to compare meaningfully. LangWatch publishes a free Developer plan, a public Launch plan at €59/month, pay-as-you-go overage for additional events, and an Enterprise/Regulated tier for controlled environments. That is a stronger buying signal than many AI quality vendors that remain mostly quote-led.