Top 5 AI Gateways for Tackling Rate Limiting in GenAI Apps

TL;DR

Rate limiting is critical for controlling costs and preventing abuse in production AI applications. This guide compares five leading AI gateways: Bifrost (Maxim's unified gateway with advanced governance), Cloudflare AI Gateway (edge-based with free tier), LiteLLM (developer-focused proxy), Kong AI (enterprise API management), and Helicone (Rust-based with GCRA limiting). Each offers distinct approaches to managing LLM traffic, from simple request caps to sophisticated token-based budgets and semantic routing.

Why Rate Limiting Matters for GenAI Apps

Production AI applications face unique challenges that make rate limiting essential:

Cost Control: A single GPT-4 call can cost $0.03+ depending on tokens. Without limits, runaway requests can drain budgets in hours. LLM cost tracking becomes critical at scale.

Provider Quotas: OpenAI enforces tier-based rate limits (requests per minute/tokens per minute). Exceeding these results in 429 errors that break user experiences.

Abuse Prevention: Public-facing AI apps are targets for prompt injection and denial-of-service attacks. Rate limiting by user ID or API key prevents single actors from monopolizing resources.

Multi-Model Complexity: Modern apps use 5+ models across providers. Each has different limits, pricing, and reliability profiles, requiring coordinated traffic management.

The 5 AI Gateways

1. Bifrost (by Maxim AI)

Platform Overview

Bifrost is Maxim's production-grade AI gateway that unifies 12+ providers (OpenAI, Anthropic, AWS Bedrock, Google Vertex) through a single OpenAI-compatible API. It combines intelligent routing with enterprise governance features designed for teams shipping reliable AI agents.

Core Rate Limiting Features

• Hierarchical Budget Management: Set spend limits at virtual key, team, and customer levels. Budgets cascade down, enabling org-wide controls with granular overrides.
• Usage Tracking: Real-time cost and token monitoring across all providers. Track spending by user, team, or project with built-in analytics.
• Request Quotas: Configure RPM (requests per minute) and TPM (tokens per minute) limits per virtual key. Prevents quota exhaustion before hitting provider limits.
• Cost-Based Limits: Unique to Bifrost: set dollar-denominated budgets ($500/month per customer) that work across all providers. The gateway tracks cumulative spend and blocks requests when thresholds are exceeded.

Advanced Governance

• Semantic Caching: Cache similar requests based on meaning, not exact matches. Reduces effective rate limit pressure by serving cached responses for 30-50% of traffic.
• Automatic Failover: When primary provider hits rate limits, Bifrost automatically routes to fallback providers without code changes. Maintains uptime during quota exhaustion.
• Load Balancing: Distribute requests across multiple API keys for the same provider. Multiplies effective rate limits by N keys.

Integration

Bifrost is a drop-in replacement for OpenAI/Anthropic SDKs. Change the base URL, and existing code works unchanged with full governance features.

Best For: Teams building production AI agents who need unified governance across multiple providers, hierarchical budgets, and seamless failover when rate limits are exceeded.

2. Cloudflare AI Gateway

Platform Overview

Cloudflare AI Gateway is an edge-based proxy that adds observability and rate limiting to AI requests. Part of Cloudflare's broader platform, it leverages their global network for low-latency traffic management.

Key Features

• Fixed and Sliding Windows: Choose between fixed time windows (resets every N minutes) or sliding windows (continuous tracking). Sliding windows prevent burst abuse.
• Global Request Caps: Set limits like "100 requests per 60 seconds" that apply across all traffic using your gateway ID. Returns 429 errors when exceeded.
• Free Tier: Core features (analytics, caching, rate limiting) are free. Ideal for startups testing multi-provider strategies.

3. LiteLLM

Platform Overview

LiteLLM is an open-source proxy that translates requests to 100+ LLM providers. Popular with developers for its flexibility and customization options.

Key Features

• Multi-Level Limits: Set RPM/TPM limits at global, team, user, and virtual key levels. Supports per-model quotas (e.g., 10 GPT-4 requests/min, 100 GPT-3.5 requests/min).
• Dynamic Rate Limiting: Priority-based allocation reserves capacity for production traffic vs. development. Example: 90% reserved for prod keys, 10% for dev.
• Redis-Based Enforcement: For multi-instance deployments, LiteLLM uses Redis to sync rate limit counters. Prevents quota overruns when running multiple gateway instances.

4. Kong AI Gateway

Platform Overview

Kong AI extends Kong's enterprise API gateway with AI-specific plugins. Strong integration with existing Kong deployments.

Key Features

• Token-Based Limiting: The AI Rate Limiting Advanced plugin uses actual token counts from LLM responses, not just request counts. More accurate cost control.
• Provider-Specific Policies: Set different limits per LLM provider (e.g., 1000 Azure tokens/min, 2000 Cohere tokens/min). Prevents single provider from dominating quota.
• Sliding Windows: Track usage over rolling time periods with adaptive strategies (local, cluster, redis) for different accuracy needs.

5. Helicone

Platform Overview

Helicone is a Rust-based AI gateway focused on observability and performance. Recently launched their open-source gateway with built-in rate limiting.

Key Features

• GCRA Algorithm: Uses Generic Cell Rate Algorithm for smooth traffic shaping with burst tolerance. More sophisticated than simple token bucket approaches.
• Multi-Scope Policies: Apply different limits at API key, user, or custom property levels. Example: "10,000 requests/hour globally, 1,000/day per user."
• Custom Headers: Configure limits via Helicone-RateLimit-Policy header (e.g., "10000;w=3600" for 10K requests per hour). Flexible per-request overrides.

Comparison Table

Choosing the Right Gateway

Start with Bifrost if you need production-ready governance across multiple providers. The combination of hierarchical budgets, semantic caching, and automatic failover addresses rate limiting holistically.

Choose Cloudflare for edge deployments where you're already on their platform and need basic request caps.

Pick LiteLLM if you have engineering resources for self-hosting and want maximum configuration flexibility.

Use Kong AI when integrating AI into existing enterprise API infrastructure with Kong Gateway.

Consider Helicone if observability integration and Rust-based performance are priorities.

For teams building reliable AI agents, the gateway is just one piece. Combine it with comprehensive AI observability and evaluation workflows to ship with confidence.

Get started: Try Bifrost with zero configuration, or book a demo to see how Maxim's full platform handles rate limiting, evaluation, and observability end-to-end.