With over 43,000 GitHub stars and adoption by companies including Nasdaq, Samsung, and Expedia, Kong Gateway is the world's most deployed open-source API gateway, processing billions of API requests daily across hybrid-cloud and multi-cloud architectures. Built on the battle-tested NGINX engine with OpenResty's LuaJIT runtime, Kong delivers sub-millisecond proxy latency while supporting REST, gRPC, GraphQL, WebSocket, SOAP, and Kafka protocols. The plugin architecture includes authentication via JWT, Basic Auth, HMAC, key authentication, OAuth 2.0, and LDAP, alongside rate limiting with configurable windows per consumer, IP address, or API key. The AI Proxy plugin provides a universal LLM API that routes across OpenAI, Anthropic, Google Gemini, AWS Bedrock, Azure AI, Databricks, Mistral, and Hugging Face through a single standardized interface, while MCP proxy capabilities convert REST APIs into MCP tools and provide traffic governance for AI agents. Kong supports declarative configuration via YAML for GitOps workflows, a RESTful Admin API for dynamic configuration, and decK CLI for version-controlled infrastructure-as-code management. Upstream health checking with active and passive probes enables automatic failover, and the ring balancer distributes traffic across upstream targets with consistent hashing, round-robin, or least-connections algorithms. The Kong Plugin Hub hosts over 100 community and official plugins covering logging, monitoring, transformation, security, and traffic control. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

KrakenD processes over 18,000 requests per second on a single instance while consuming under 50MB of RAM at 1,000 concurrent connections, operating as a stateless API gateway that requires no database whatsoever. The Community Edition has earned over 2,600 GitHub stars by outperforming database-dependent alternatives like Kong and Tyk in independent benchmarks. Written entirely in Go, it uses declarative JSON or YAML configuration files that integrate directly into GitOps workflows for version-controlled infrastructure management. The gateway aggregates responses from multiple backend services into a single API call, transforms request and response payloads with field filtering, grouping, and mapping, and applies zero-trust security policies including JWT validation, OAuth 2.0, CORS, HSTS, clickjacking protection, and XSS prevention. Traffic management features include multi-layer rate limiting at both the router and proxy levels, circuit breakers for backend fault isolation, spike arrest policies, and concurrent call support that requests the same data from multiple backends in parallel for improved response times. Telemetry integrates with OpenTelemetry, Prometheus, Grafana dashboards, Datadog, Zipkin, and Jaeger for distributed tracing and metrics collection. The gateway extends through Go plugins, Lua scripting, Martian modifiers, and Google CEL expressions for custom request processing logic. AI workload routing supports OpenAI, Anthropic, Gemini, and other model endpoints with built-in fallback, retries, and load balancing. Deploy via Docker with the devopsfaith/krakend image as a single binary. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

Backed by the Linux Foundation with contributions from AWS, Cisco, IBM, Microsoft, Red Hat, and Shell, Agentgateway is the first data plane built from the ground up for AI agent workloads — providing a unified Rust-based proxy that handles conventional HTTP and gRPC traffic alongside MCP tool servers, A2A agent communication, and LLM inference endpoints through a single deployment. The LLM gateway routes requests to OpenAI, Anthropic, Gemini, AWS Bedrock, and other providers through an OpenAI-compatible unified API with per-tenant budget controls, spend tracking, prompt enrichment, load balancing across multiple model endpoints, and automatic failover when providers experience outages. The MCP gateway federates multiple tool servers behind one endpoint, supporting stdio, HTTP/SSE, and Streamable HTTP transports with built-in OAuth authentication compliant with the MCP auth specification, integrating Auth0 and Keycloak out of the box. OpenAPI integration exposes existing REST APIs as MCP-native tools without code changes, enabling legacy services to participate in agent workflows. Policy-based RBAC controls which agents access which tools, while OpenTelemetry integration provides distributed tracing across agent communication chains. Deploy as a standalone binary with flat YAML configuration or on Kubernetes using the built-in controller with Gateway API support for declarative infrastructure-as-code management. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

Unkey is the open-source platform that unifies API key management, rate limiting, deployment, and observability into a single control plane. The Go API service validates keys with sub-millisecond latency using regional Redis caches and MySQL 8.0 persistent storage, while ClickHouse captures every verification event for per-key and per-keyspace analytics with filterable time-series charts, request counters, and active key tracking. Keyspaces organize API keys by product, environment, or tier, each configurable with custom prefixes, byte lengths, IP whitelists, encrypted key recovery, and delete protection. Per-key settings include expiration dates, rate limit quotas with configurable windows, RBAC roles and permissions, owner identities linking multiple keys to a single user or organization, and key rotation with grace periods from immediate revocation through 24-hour overlap. The deployment pipeline connects GitHub repositories for automatic Docker container builds, generates preview environments per commit, promotes tested versions to production, and validates releases with OpenAPI diff detection flagging breaking changes before production. The edge gateway authenticates and rate-limits requests at the closest region before routing to the nearest API instance. Immutable audit logs track every key creation, verification, deletion, and configuration change with actor, timestamp, and event metadata. The CLI provides terminal access to key management, analytics queries, and deployment operations. On RepoCloud, deploy Unkey on a dedicated VPS with Docker, root SSH access, and complete control over your API infrastructure, all under the AGPL license.

With 17,000 GitHub stars, 460+ contributors, and deployments across telecommunications, automotive, and financial services running on over 10,000 CPU cores at the largest known installations, Apache APISIX delivers a fully dynamic API gateway achieving 140,000 QPS on eight cores with sub-millisecond latency through NGINX's event-driven architecture and LuaJIT-compiled plugin execution. The 100+ open-source plugins cover authentication (JWT, OAuth 2.0, OIDC, Keycloak, LDAP), observability (Prometheus, Datadog, SkyWalking, OpenTelemetry), traffic management (rate limiting, circuit breaking, canary releases, traffic splitting), and security (CORS, IP restriction, CSRF protection) — all hot-reloadable without process restarts via etcd-based real-time configuration synchronization. Multi-protocol support handles HTTP, gRPC, MQTT, TCP, UDP, and WebSocket traffic for both north-south API access and east-west service mesh communication. AI gateway capabilities proxy requests to 20+ LLM providers with semantic caching, token-aware rate limiting, provider failover routing, and content moderation. Custom plugins extend the gateway in Lua, Go, Java, Python, or WebAssembly. Radixtree route matching handles 100,000+ routes without performance degradation. Functions as a Kubernetes ingress controller with native service discovery for Consul, Nacos, and Eureka. Deploy via Docker or Helm charts with horizontal scaling through etcd cluster coordination. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.