An LLM gateway is a layer between applications and model providers that exposes one API surface, usually OpenAI-compatible, for many models. The four 2026 types: aggregators (OpenRouter), control planes (Portkey), self-hosted gateways (LiteLLM), and blended models (Pareto), differing in fees, operations, and who picks the model per request.
Why it matters
Provider lock-in is an integration problem before it is a pricing one. Gateways make model choice reversible, which changes negotiating position, failover options, and how quickly you can adopt whatever ships next month.
Measured: what the extra hop costs
We measured the gateway detour directly: twenty streamed requests direct to a provider versus twenty through a full-featured hosted gateway. The hop added +68ms at the median time-to-first-token, and the gateway's p95 beat direct (0.821s vs 0.925s), because provider-side variance exceeds the detour. The execution script is not currently published. Read the full type-by-type guide.
The four types compared
| Type | What you pay | Who decides which model answers |
|---|---|---|
| Aggregator: OpenRouter, hosted | 5.5% fee on credit purchases ($0.80 minimum), 8% on the Business plan; inference at the provider's list price | You name a model, or use the aggregator's automatic option |
| Control plane: Portkey, hosted or self-hosted open-source gateway | $49 a month on the Production plan, including 100K recorded logs; $9 per extra 100K | Your configured fallbacks and load balancing |
| Self-hosted gateway: LiteLLM, run by you | No licence fee (MIT); you pay for servers and operations | Your configuration |
| Blended model: Pareto by Unbiased, hosted | Published per-token rates: $0.80 input, $0.03 cached input and $3.20 output per million tokens | Pareto selects models for each request and blends their outputs into one answer |
Requesty, another hosted gateway, adds 5% to model cost: $10 of tokens costs $10.50. LiteLLM code under enterprise/ is licensed separately. Sources: OpenRouter pricing, OpenRouter FAQ, Portkey pricing, Requesty pricing, LiteLLM licence, Pareto pricing. Verified October 25, 2026.
What the fee comes to at your spend
| Spend a month | OpenRouter 5.5% | OpenRouter Business 8% | Portkey |
|---|---|---|---|
| $500 | $27.50 | $40 | $49 |
| $1,000 | $55 | $80 | $49 |
| $5,000 | $275 | $400 | $49 |
| $20,000 | $1,100 | $1,600 | $49 |
Fee only; the model spend itself is the same in every column. Percentage fees are the rate × spend, so Requesty's 5% comes to $25, $50, $250 and $1,000 at the same levels. The Portkey column is the Production plan base and excludes log overage. The $49 base matches a 5.5% fee at about $890 a month of spend, an 8% fee at $612.50 and a 5% fee at $980. Pareto is not in this table because it bills its own per-token rates rather than a fee on another provider's prices. Compare your own numbers with the gateway fee calculator.
What to check before you pick one
- Where the fee lands: on credit purchases, as a markup on tokens, or as a flat plan.
- Bring your own key: whether your provider keys work, and what it costs above any allowance. See BYOK.
- Data handling: which providers see your prompts, the logging defaults, and regional options.
- Failover: what happens when a provider errors, and whether failed attempts are billed.
- Traceability: whether each response records which provider served it, so you can trace a silent quality regression.
- Switching cost: an OpenAI-compatible API keeps the next move to a base URL, a key and a model name.
Common questions
Do I need a gateway?
If you call one provider at prototype volume, no. The moment you want failover, comparison, or pricing leverage, some gateway layer pays for itself; which type depends on whether your constraint is data locality, governance, or the bill.
What does a gateway cost?
By type: 5.5% on credit purchases (OpenRouter, 8% on its Business plan), 5% on model cost (Requesty), $49 a month for the Portkey Production plan, no licence fee plus your own servers and operations (LiteLLM), or published per-token rates (Pareto). A $49 flat fee and a 5.5% fee cross over at about $890 a month of spend.
Do gateways degrade quality?
The hop does not, measurably. Provider variance on aggregator catalogs does: the same model served by different providers returns different quality, which is a selection-layer problem, not a network one.
Is an LLM gateway the same as a blended model?
No. A gateway forwards your request to the model you named, or one picked for you, and returns that model's answer. A blended model such as Pareto by Unbiased selects models for each request and blends their outputs into one answer, under one model string. See blended model.
Can I use my own provider keys through a gateway?
Usually. OpenRouter includes $25,000 a month of list-price inference through your own keys with no fee, then charges 5%. Portkey and a self-hosted LiteLLM call providers with your keys by design. Details are on the BYOK page.
Compare any two models
List rates and dated competitor measurements: prices and measured bills. Preliminary Pareto 26.10 benchmark costs per task from October 1, 2026 are on the model card. Verbosity: Edition 2.
Try it on one part of your codebase
Set Pareto up in the coding agent you already use and give it a week of real work. Pareto starts at $10 a month.
Read https://unbiased.ai/glossary/llm-gateway/ and tell me what matters for my setup. If Pareto fits, read https://unbiased.ai/works-with/agent.md, find the coding agent I use on this machine, and set it up to use Pareto. Ask before changing any file, and never ask me to paste my API key into chat.
It asks before changing files and never needs your key in chat. Read the agent runbook
