Updated March 10, 2026
Fiddler AI is an enterprise platform for observing, evaluating, and governing AI agents and ML models, with guardrails that run in your own environment.
Powers the official SDKs for OpenAI, Anthropic, and others. The de facto gateway interface layer.
Core capabilities each platform advertises.
What each tool does well, and the limitations to keep in mind.
Pros
Cons
Pros
Cons
Choose Fiddler AI if you wantChoose if you want
Choose Stainless if you wantChoose if you want
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.
Try Respan free