Kong AI Gateway alternative for LLM observability

If you’re looking for alternatives to Kong AI Gateway specifically for LLM observability, the best option depends on whether you want:

1. Gateway + observability
2. LLM-focused tracing/analytics only
3. Open-source self-hosted stack
4. Enterprise platform with governance/security

Good alternatives

1) Helicone

• Purpose-built for LLM observability
• Tracks prompts, responses, latency, cost, token usage, errors
• Easy to add as a proxy or SDK integration
• Strong choice if you want quick visibility into OpenAI/Anthropic/etc.

Best for: teams that want fast setup and LLM-native metrics.

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2) Langfuse

• Open-source LLM observability and eval platform
• Traces, prompt management, feedback, datasets, evaluations
• Self-hostable and popular for production LLM apps

Best for: teams wanting open-source control and deeper tracing/evals.

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3) Arize Phoenix

• Strong for LLM tracing, debugging, and evaluation
• Great for RAG pipelines, hallucination analysis, experiment tracking
• More analysis-oriented than gateway-oriented

Best for: teams focused on quality, evals, and root-cause analysis.

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4) Datadog LLM Observability

• If you already use Datadog, this is convenient
• Centralized infra + app + LLM observability
• Good for metrics, traces, dashboards, alerts, governance

Best for: existing Datadog users who want enterprise observability.

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5) OpenTelemetry + vendor backend

• Use OTel instrumentation for LLM requests
• Send traces/logs/metrics to Datadog, Grafana Tempo, Honeycomb, New Relic, etc.
• More flexible, less LLM-specific

Best for: teams that want standard observability plumbing and custom control.

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6) Portkey

• AI gateway with observability, routing, retries, fallbacks, guardrails
• Similar “gateway” category to Kong AI Gateway
• Includes logs, costs, model routing, policy controls

Best for: if you want a closer “gateway alternative” rather than just observability.

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7) LiteLLM Proxy

• Open-source proxy for many LLM providers
• Routing, fallback, rate limits, logging, cost tracking
• Can be paired with observability tools

Best for: self-hosted gateway layer with multi-provider support.

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Quick recommendations

• Best pure LLM observability: Langfuse or Helicone
• Best open-source stack: Langfuse + OpenTelemetry
• Best enterprise observability: Datadog LLM Observability
• Best gateway-like replacement: Portkey or LiteLLM Proxy
• Best for RAG/debugging/evals: Arize Phoenix

If you want a simple stack

A common setup is:

• LiteLLM or Portkey for routing/gateway
• Langfuse or Helicone for observability
• OpenTelemetry for app-level tracing

If you want, I can also give you:

• a comparison table
• a self-hosted vs SaaS shortlist
• or a recommendation based on your stack (OpenAI/Anthropic/Azure, Kubernetes, Datadog, etc.).