Best AI API Gateways in 2026: OpenRouter, Together, Helicone, Portkey & Celedog Compared
One API key, every model — but the gateways that promise it differ a lot. Here's how the main options actually compare in 2026.
An AI API gateway sits between your application and the underlying model providers (OpenAI, Anthropic, Google, DeepSeek and others). Instead of integrating each provider separately — different SDKs, keys, billing accounts and error shapes — you call one endpoint and switch models by changing a single string. The trade-offs between gateways come down to four things: how many models they reach, whether they route intelligently, how they bill, and how cleanly they drop into your existing SDK.
At a glance
| Gateway | Models | Auto-routing | Billing | Best for |
|---|---|---|---|---|
| Celedog | 200+ curated | Yes (5 capability routes) | PAYG + monthly packs, USD/CNY/IDR | Multi-provider access with China/Indonesia payment rails |
| OpenRouter | 300+ broad | No built-in | PAYG, USD only | Widest open-source catalog |
| Together AI | Open-source hosted | No | PAYG, USD | Hosting + fine-tuning open models |
| Helicone | Proxy to providers | No | Usage-based, observability tiers | Logging & observability |
| Portkey | Proxy to providers | Configurable | Per-seat + usage | Guardrails & governance |
| LiteLLM | Self-hosted proxy | Configurable | Free (you host) | Teams that want to self-host |
| Cloudflare AI Gateway | Front of your providers | No | Free tier + usage | Caching & analytics at the edge |
Celedog
Celedog is a developer-first gateway aggregating 200+ curated models from 30+ providers behind one OpenAI-compatible endpoint. Its differentiators are intelligent auto-routing (meta-models like celedog/auto-cheapest, celedog/auto-coding, celedog/auto-reasoning, celedog/auto-chat, celedog/auto-chinese that resolve to a concrete model per request), native passthrough for both the OpenAI and Anthropic protocols (so Claude Code and the official SDKs work unchanged), and multi-currency billing in USD, CNY and IDR with local payment rails (Stripe, Alipay, WeChat Pay, Xendit). Pricing is pay-as-you-go with optional monthly packs for the best per-token rate. It's the strongest fit if you need cross-border access — especially China-compliant routing or Indonesian payment methods — without stitching providers together yourself.
OpenRouter
OpenRouter has the broadest catalog (300+ models, heavy on the open-source long tail) and a clean OpenAI-compatible API. It's USD-only and has no built-in cost/quality auto-routing — you pick the model. If raw breadth of the open-source catalog is your priority and you bill in USD, it's a solid default.
Together AI
Together AI runs its own GPU infrastructure, hosts open-source models, and offers fine-tuning — but it does not resell proprietary models like GPT, Claude or Gemini. Choose Together when you want to host or fine-tune open-weights models; choose a gateway when you need proprietary models behind the same API.
Helicone
Helicone is primarily an observability proxy: it sits in front of your existing provider keys and gives you logging, cost tracking, caching and tracing. It's complementary to a gateway rather than a replacement — great when your main need is visibility into an existing OpenAI/Anthropic integration.
Portkey
Portkey focuses on governance: guardrails, prompt management, fallbacks and per-team controls on top of a provider proxy. It shines for enterprises that need policy enforcement and request governance more than raw model breadth.
LiteLLM
LiteLLM is an open-source proxy you self-host. It normalizes 100+ providers to the OpenAI format and supports routing rules you configure. It's free (you run the infrastructure and absorb the ops burden), which suits teams that want full control and have the engineering capacity to operate it.
Cloudflare AI Gateway
Cloudflare AI Gateway adds caching, rate-limiting and analytics at the edge in front of your own provider accounts. It doesn't aggregate or resell models — you still bring your own provider keys — but it's a low-friction way to add edge caching and observability.
How to choose
- Need proprietary + open models behind one key, billed in your local currency? A reselling gateway like Celedog or OpenRouter.
- Operating in or selling to China / Indonesia? Celedog's compliant routing and local payment rails are the clearest fit.
- Want automatic cost optimization? Look for built-in auto-routing (Celedog) rather than a plain proxy.
- Mainly need logging/observability over an existing integration? Helicone or Cloudflare AI Gateway.
- Want to self-host and control everything? LiteLLM.
If you want to try a multi-provider gateway with auto-routing and multi-currency billing, create a Celedog account — signup credit covers the first few thousand requests — or browse the full model catalog and live pricing.
Written by Celedog Team · Last updated June 3, 2026
Where to go next
- Try Celedog — free credits on signup, no card required.
- API documentation
- Per-model pricing
- More Celedog Comparison Hub