In the GenAI gold rush, Every developer, startup, and enterprise is scrambling to build the next killer AI-powered application. But beneath the shiny surface lies a messy, complex, and expensive reality: connecting to Large Language Models (LLMs) is a infrastructural nightmare.
Traditional API gateways, the trusted gatekeepers of the cloud-native world, are buckling under the punishing demands of AI traffic, here lets explore this problem of making AI models accessible anywhere at scale with Envoy AI Gateway & learn the shift in how we manage, scale, and control the flow of AI, built on the foundation of popular cloud-native proxy, Envoy.
Problem: Why Your Old Gateway Can’t Handle New AI
Managing GenAI traffic isn’t just about routing requests; it’s a whole new set of challenges:
The Fractured Model Universe: Your app might want to use GPT-4 for complex reasoning, Claude 3 for long-context tasks, and a self-hosted Llama 3 for cost-efficiency. Each has a different API schema, different authentication, and different performance characteristics, making application code a tangled mess of SDKs and conditional logic.
Cost is Unpredictable and Explosive: Unlike a API call, the cost of an LLM request isn’t flat rate, but based on tokens—the number of words or parts of words in both input and the model’s output. A long, complex request can cost hundreds of times more than a short one. Traditional rate-limiting (e.g., 100 requests/minute) is no longer useful for budget control.
Latency is Long and Variable: LLMs think rather than just fetching data. A response can take many seconds or even minutes to generate. This requires a completely different approach to timeouts, retries, and user experience, often involving streaming responses token-by-token.
The Resilience Roulette: When model provider has an outage or is running at full capacity? Your application experiences same, for fallback you need to incorporate more intelligent, cross-provider workloads to maintain high availability, but building this is a significant engineering effort.
Security and Safety are Paramount: Managing dozens of API keys securely. More importantly, to filter both prompts and responses for harmful content, PII, and other sensitive data in real-time.
Doing this in every single application is redundant, insecure, and unscalablem needing a solution to this at the infrastructure layer.
What is Envoy AI Gateway? How does it solve problem?
Envoy AI Gateway is an open-source, AI-native gateway designed to solve the challenges of GenAI traffic. It’s a sub-project of the Envoy Proxy ecosystem with mission to act as a universal translator and an intelligent control point for all your AI services.
Envoy AI Gateway builds on the robust, high-performance, and incredibly extensible foundation of Envoy Proxy, extending its popular filter chain mechanism to handle AI-specific tasks.
Core Features of Envoy AI Gateway
Unified API: Speak One Language to All LLMs
Application can speak a single, standardized API format (e.g., the OpenAI API format) to the gateway. Envoy AI Gateway then transparently transforms that request into the specific format required by the backend, whether it’s Azure OpenAI, AWS Bedrock, Google’s Gemini, or a self-hosted model completely decoupling application from the backend model.
Switch from GPT to Claude can be achieved with simple configuration change in the gateway, with zero changes to your application code.
Cost-Based Rate Limiting: Finally, Control Your AI Budget
Envoy AI Gateway understands the concept of „token usage“ enabling to set rate limits based on cost, not just request counts.
An example AIGatewayRoute CRD :
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: AIGatewayRoute
metadata:
name: azure-gpt4o
spec:
# ... other routing config
limitRequestCosts:
# A CEL expression calculating cost based on tokens
- cel: 'input_tokens / 1.0 + output_tokens * 3.0'
# Metadata key to store the calculated cost
metadataKey: tokenCost
# ... more routing config
In the above policy, we defined a flexible cost formula.
The gateway can enforce rules like „Allow 500,000 cost units per minute,“ providing precise control over spending across different user tiers.
Intelligent Load Balancing and Fallbacks
The gateway is capable of managing traffic with priority-based routing.
# ...
rules:
- backendRefs:
- name: azure-backend
priority: 0 # Highest priority
- name: openai-backend
priority: 1 # Fallback
# ...
When the primary backend (azure-backend) becomes unavailable or runs out of capacity, the gateway will automatically and seamlessly spill over the traffic to fallback backend (openai-backend) providing critical resilience for applications without complex client-side logic.
Centralized Security and Credential Management
Stop scattering API keys across applications and environment variables. With BackendSecurityPolicy CRD, manage all credentials in one secure, central place.
Even supporting advanced mechanisms like OIDC Federation, allowing the gateway to use its own identity to securely exchange temporary credentials with cloud providers like AWS and Azure eliminating the need for long-lived static keys and automates credential rotation, dramatically improving your security posture.
How It Works: A Glimpse Under the Hood
Envoy AI Gateway’s architecture leverages the existing Envoy Gateway project for its control plane and introduces its controller.
Users define AI-specific needs using simple CRDs like AIGatewayRoute.
The Envoy AI Gateway controller translates these into standard Gateway API resources.
It then uses Envoy’s powerful External Processing (ExtProc) extension to inject AI-specific logic.
An ExtProc sidecar runs alongside the main Envoy pod, handling tasks such as token counting, request/response transformation, and content moderation keeping the core Envoy proxy lean and fast while allowing for rich, AI-specific functionality to be developed and deployed independently.
Envoy AI Gateway kind of projects are laying the foundation for a more standardized, secure, and cost-effective MLOps and LLMOps landscape. By solving complex problems at the infrastructure level, freeing developers to continue to build amazing applications.
Ready to tame your AI traffic?
GitHub: github.com/envoyproxy/ai-gateway
Web : aigateway.envoyproxy.io
More : https://youtu.be/xk1HsvVHMtA?si=WzyJHxKzpKDVf5Sp