8 Best AI Gateway Alternatives in 2026 (Open Source)

AI Gateway — A blazing fast AI Gateway with integrated guardrails. Route to 200+ LLMs, 50+ AI Guardrails with 1 fast & friendly API. vs LiteLLM: production-focused with guardrails, caching, and MCP Gateway; vs OpenRouter: self-hostable with enterprise governance and conditional routing rather than just model access

These 8 open-source tools do the same job. They are ordered by how closely they match AI Gateway, with live GitHub data so you can see which projects are actively maintained.

By package downloads LiteLLM is the most used here (89.4M in the last 30 days), even though OmniRoute has the most GitHub stars. See all agent tools by downloads.

1. 1. LiteLLM

   Open-source Python SDK and AI gateway for calling 100+ LLMs through a unified OpenAI-compatible interface

   What sets it apart: Unlike OpenRouter (hosted-only routing), LiteLLM is self-hostable and provides a full gateway with per-user spend tracking, virtual keys, and A2A/MCP protocol support — making it the enterprise LLM traffic controller

   Best for: ML platform teams managing multi-provider LLM access with centralized cost tracking and auth; Developers switching between LLM providers without changing application code

   ⭐ 60.1kAI Gateway vs LiteLLM →Full profile →

2. 2. Bifrost AI Gateway

   Fastest enterprise AI gateway (50x faster than LiteLLM) with adaptive load balancer, cluster mode, guardrails, 1000+ models support & <100 µs overhead at 5k RPS.

   What sets it apart: Fastest AI gateway with 11us overhead at 5k RPS — built in Go for extreme performance vs LiteLLM/Portkey's Python-based proxies

   Best for: High-throughput production AI gateways needing sub-millisecond overhead; Multi-provider failover with zero-downtime requirements

   ⭐ 8.5kAI Gateway vs Bifrost AI Gateway →Full profile →

3. 3. TensorZero

   TensorZero is an open-source LLMOps platform that unifies an LLM gateway, observability, evaluation, optimization, and experimentation.

   What sets it apart: Only LLM gateway that combines inference, observability, evaluation, and optimization in one Rust-based system with data flywheel — vs LiteLLM (routing only) or Langfuse (observability only)

   Best for: Teams wanting a unified LLM gateway with built-in optimization feedback loop; Production systems needing <1ms latency overhead at scale; Organizations wanting to continuously improve LLM performance from production data

   ⭐ 11.7kAI Gateway vs TensorZero →Full profile →

4. 4. OmniRoute

   OpenAI-compatible gateway for multi-provider routing, retries, fallbacks, caching, and observability

   What sets it apart: It combines an OpenAI-compatible endpoint with broad provider routing, quota-aware failover, token compression, and a maintained free-tier catalog.

   Best for: Developers building agents or coding workflows across multiple model providers; Teams seeking a single OpenAI-compatible endpoint with provider failover; Users managing multiple provider quotas and free tiers

   ⭐ 72.5kAI Gateway vs OmniRoute →Full profile →

5. 5. Manifest

   Smart LLM Routing for OpenClaw. Cut Costs up to 70% 🦞🦚

   What sets it apart: Free, open-source, local-first LLM router with transparent scoring — vs OpenRouter which is a cloud proxy with 5% fee and no routing transparency

   Best for: Reducing LLM API costs by routing to cheapest capable model; Teams using multiple LLM providers who want automatic failover

   ⭐ 7.6kAI Gateway vs Manifest →Full profile →

6. 6. NadirClaw

   Open-source LLM router and cost optimizer with an OpenAI-compatible proxy

   What sets it apart: Local-first LLM cost optimizer — classifies prompt complexity in 10ms and routes simple requests to 10-20x cheaper models, with no third-party proxy or middleman

   Best for: Teams spending heavily on LLM APIs wanting 40-70% cost reduction; AI coding assistants (Claude Code, Cursor) with mixed complexity prompts; Budget-conscious developers using multiple LLM providers

   ⭐ 655AI Gateway vs NadirClaw →Full profile →

7. 7. helicone

   🧊 Open source LLM observability platform. One line of code to monitor, evaluate, and experiment. YC W23 🍓

   What sets it apart: vs LangSmith/Braintrust: Combined AI Gateway + Observability platform with one-line integration, generous free tier, unified access to 100+ models, and built-in prompt versioning - Y Combinator backed

   Best for: Teams needing unified observability across multiple LLM providers; Production AI apps requiring cost tracking and prompt management; Developers wanting a single API gateway for 100+ models

   ⭐ 6.2kAI Gateway vs helicone →Full profile →

8. 8. OpenLIT

   Open-source platform for AI agent tracing, evaluations, guardrails, prompts, and GPU monitoring

   What sets it apart: Most comprehensive open-source AI engineering platform — combines observability, 11 evaluation types, rule engine, prompt hub, secret vault, playground, and fleet management in one tool

   Best for: Teams wanting all-in-one LLM platform (observability + eval + prompts + secrets); Organizations needing self-hosted AI engineering platform; Multi-language teams (Python/TS/Go SDK support)

   ⭐ 2.8kAI Gateway vs OpenLIT →Full profile →