Kong AI Gateway vs Apache APISIX: Streaming LLM Proxy

Kong AI Gateway excels at providing a mature, plugin-rich ecosystem purpose-built for API management, now extended to AI. Its strength lies in its vast library of over 200 plugins and deep enterprise integrations, allowing teams to apply existing API security, rate limiting, and observability policies directly to LLM traffic. For example, Kong's ai-proxy plugin can enforce token-level rate limits and PII redaction on streaming responses with sub-millisecond overhead, leveraging its Lua-based runtime for high-performance inline transformations.

Apache APISIX takes a different approach by prioritizing raw performance and flexibility through a multi-language plugin architecture. Its core is built on NGINX and etcd, delivering exceptionally low latency and high throughput for routing decisions. APISIX allows custom streaming processing plugins to be written in Go, Python, or WebAssembly, which can result in more efficient connection pooling and load balancing for long-lived SSE connections. This architecture is particularly advantageous for teams that need to implement custom, non-standard streaming logic without the constraints of a Lua-only environment.

The key trade-off: If your priority is a turnkey, enterprise-grade solution with pre-built AI governance plugins and seamless integration with existing Kong deployments, choose Kong AI Gateway. If you prioritize maximum throughput, minimal routing latency, and the flexibility to build custom streaming logic in languages like Go or Rust, choose Apache APISIX. Consider Kong when you need to enforce a unified API management strategy across all services, including AI. Choose APISIX when raw proxy performance and customizability for high-scale streaming are your primary architectural drivers.

Kong AI Gateway excels at providing a mature, enterprise-grade API management ecosystem with a specific, rapidly evolving AI plugin suite. Its strength lies in the breadth of its over 200 plugins and deep integration with the CNCF ecosystem, making it a natural choice for organizations already standardized on Kong for north-south traffic. For streaming LLM workloads, Kong's ai-proxy plugin provides a unified interface for multiple LLM providers, handling SSE connection management with features like rate limiting and prompt templating out-of-the-box. This results in a faster time-to-market for teams who value a curated, commercially-backed experience, with Kong Konnect reporting a 60% reduction in time to deploy new AI services for existing customers.

Apache APISIX takes a fundamentally different, performance-first approach, built on a data-plane-first architecture with a custom, low-latency LuaJIT core. This design choice results in a significantly smaller performance overhead, with benchmarks showing APISIX handling over 180,000 requests per second with a p99 latency under 2ms on commodity hardware, compared to Kong's ~50,000 RPS in similar tests. For streaming LLM proxies, this translates to a more efficient handling of long-lived SSE connections, where APISIX's non-blocking I/O model minimizes CPU context switching. Its plugin ecosystem, while smaller, is entirely open-source and leverages a hot-reloading mechanism that allows for dynamic updates to routing and security policies without dropping active connections.

The key trade-off: If your priority is a fully integrated, enterprise-supported platform with a rich set of pre-built AI governance and security plugins, choose Kong AI Gateway. If your absolute priority is raw, high-throughput, low-latency performance for a massive number of concurrent streaming connections with a fully open-source core, choose Apache APISIX. Consider Kong when you need to buy a comprehensive solution; choose APISIX when you need to build a high-performance, customizable proxy layer.