Are there any prompt routing platforms that handle A/B testing across model providers without breaking production SLAs?

Yes — there are a few prompt-routing / LLM gateway platforms that support A/B testing or traffic splitting across multiple model providers while still being designed for production reliability, fallback handling, and SLA-friendly routing.

A few notable options:

1) LiteLLM Proxy / LiteLLM Enterprise

• Supports routing to many providers behind one OpenAI-compatible API.
• Can do fallbacks, load balancing, rate-limit handling, and model routing.
• Useful for A/B tests, canary deployments, and provider failover.
• Good fit if you want to keep app code stable while switching providers.

2) Portkey

• AI gateway with routing, fallbacks, retries, and observability.
• Supports traffic splitting / experimentation patterns.
• Often used to abstract multiple LLM providers in production.
• Emphasis on reliability and control rather than just experimentation.

3) Helicone

• Primarily an LLM observability layer, but also supports request routing and experimentation patterns.
• Can help with tracing, logging, and comparing providers/models.
• More observability-first than pure gateway-first.

4) OpenRouter

• Aggregates many model providers under one API.
• Useful for quick provider switching and comparison.
• More of a unified access layer than a strict production SLA management platform, so you’d want to validate SLA/fallback requirements carefully.

5) LangSmith / LangGraph + custom router

• Not a classic gateway, but can support evaluation and experimentation workflows.
• Best if your team is building a more custom routing and eval setup.

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What to look for if SLA matters

For “without breaking production SLAs,” you’ll want the platform to support:

• Timeouts and retries
• Automatic fallback providers
• Rate-limit-aware routing
• Health checks
• Circuit breaking
• Per-provider latency/error monitoring
• Sticky routing for consistent A/B assignment
• Sampling controls so only a fraction of traffic is exposed to experiments
• Idempotency / request replay safety if applicable

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Practical recommendation

If your main goal is production-safe A/B testing across providers, the shortest path is usually:

• LiteLLM Proxy if you want a flexible open routing layer
• Portkey if you want a managed gateway with enterprise controls
• Helicone if observability/comparison is as important as routing

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If you want, I can also give you a side-by-side comparison table of these platforms specifically for:

• A/B testing
• fallback behavior
• SLA safeguards
• enterprise maturity
• self-hosted vs managed deployment