8 Best TensorZero Alternatives in 2026 (Open Source)
TensorZero is an open-source LLMOps platform that unifies an LLM gateway, observability, evaluation, optimization, and experimentation. 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)
Short answer
- Closest match to TensorZero: AI Gateway.
- Most actively developed: LiteLLM (13,191 commits in the last 90 days).
- Fastest growing: OmniRoute (+11,258 GitHub stars in the last 30 days).
These 8 open-source tools do the same job. They are ordered by how closely they match TensorZero, with live GitHub data so you can see which projects are actively maintained.
| Tool | GitHub stars | Stars / 30d | Last commit |
|---|---|---|---|
| TensorZero(original) | 11.7k | +89 | 2026-06-04 |
| AI Gateway | 13.1k | +325 | 2026-05-25 |
| LiteLLM | 60.0k | +2,991 | 2026-10-02 |
| Bifrost AI Gateway | 8.5k | +832 | 2026-10-02 |
| OmniRoute | 72.2k | +11,258 | 2026-10-02 |
| Agenta | 4.8k | +130 | 2026-10-02 |
| Langfuse | 35.3k | +1,812 | 2026-10-02 |
| Pezzo | 3.3k | +10 | 2026-08-21 |
| OpenLIT | 2.8k | +77 | 2026-10-01 |
1. AI Gateway
A blazing fast AI Gateway with integrated guardrails. Route to 200+ LLMs, 50+ AI Guardrails with 1 fast & friendly API.
What sets it apart: 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
Best for: Teams using multiple LLM providers needing unified routing; Production AI apps requiring reliability (retries/fallbacks); Organizations wanting centralized LLM cost and access control
2. 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
3. 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
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
5. Agenta
The open-source LLMOps platform: prompt playground, prompt management, LLM evaluation, and LLM observability all in one place.
What sets it apart: Unified open-source LLMOps platform combining prompt playground, version control, 20+ evaluators, and OTel-native observability in one tool — vs separate tools for each
Best for: Teams needing integrated prompt management + evaluation + observability; Product teams collaborating with SMEs on prompt engineering; Organizations wanting open-source LLMOps alternative
6. Langfuse
Open-source LLM engineering platform for observability, evaluation, prompt and dataset management
What sets it apart: Unlike LangSmith (LangChain-specific) or Helicone (proxy-based), Langfuse is fully open-source, framework-agnostic, and self-hostable, combining tracing, prompt management, evaluations, and datasets in a single platform built on ClickHouse for scalable production use.
Best for: Teams operating production LLM applications who need tracing, prompt management, and evaluation in one platform; Organizations requiring self-hosted LLM observability for data privacy compliance
7. Pezzo
🕹️ Open-source, developer-first LLMOps platform designed to streamline prompt design, version management, instant delivery, collaboration, troubleshooting, observability and more.
What sets it apart: Pezzo combines open-source prompt management and delivery with observability, troubleshooting, and caching in one LLMOps platform.
Best for: Developers operating LLM applications; Teams collaborating on prompts; Teams seeking a self-hosted LLMOps stack
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)
FAQ
- What are the best alternatives to TensorZero?
- The closest open-source alternatives to TensorZero are AI Gateway, LiteLLM and Bifrost AI Gateway, followed by OmniRoute, Agenta and Langfuse. They are ranked by how closely they match what TensorZero does.
- Which TensorZero alternative is the most popular?
- OmniRoute has the most GitHub stars among TensorZero alternatives, with 72,229 stars.
- Which TensorZero alternative is the most actively maintained?
- By recent activity, LiteLLM (13,191 commits in the last 90 days) is the most actively developed alternative.