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OpenRouter gives developers a single API to route requests across hundreds of models, helping them cut costs, improve performance, and avoid being locked into any model.
To help you start routing LLM requests through OpenRouter, you’ll need to generate a unique API key.
This guide helps you do just that.
You’ll be prompted to log in. You can do so through OAuth, with your email and password, or through a passkey.
You can also create an account at this step if you don’t have one set up.

Related: How OpenRouter works
You’ll see a pop-up that asks for specific information on your API key.

Through the pop-up, you can:
Your API key should now be generated!

Copy it and save it in a password manager like 1Password. Fortunately, OpenRouter lets you do this with a few clicks.
Related: The best alternatives to OpenRouter
Gateway is Merge’s control layer for running LLMs in production.
It uses a single API that sits between your product and multiple model providers, and lets you centrally route requests, enforce budgets/policies, and keep AI features reliable (via fallbacks) with request-level visibility.

Unlike OpenRouter, it offers:
Start testing Merge Gateway today by signing up for a free account.
In case you have any more questions on OpenRouter’s API, we’ve addressed several more common questions below.
Yes, since it’s free to create an account, anyone can create an API key without incurring any costs. That said, once you start using the API key, you can be charged by OpenRouter and the LLMs you route requests to.
You're billed per token (input and output are priced separately) at each model provider's own rates. OpenRouter passes those rates through with no markup, so you pay the provider's cost.
However, OpenRouter charges a platform fee on spend, (e.g., 5.5% on Pay-as-you-go), which can quickly increase as you scale usage.
OpenRouter supports hundreds of models from closed and open-sourced providers.
Commonly-used models include DeepSeek V4 Flash, MiniMax M3, Claude Opus 4.7, and Claude Sonnet 4.6.
Your rate limit depends on whether you’re calling free or paid models and, if you're calling free models, how many credits you've purchased on your account.
Free models have a fixed per-minute cap, plus a daily cap that scales with your lifetime credit purchases:
Paid models aren't bound by those free-tier daily caps. Their usage is limited by your credit balance and the provider's capacity. And if your balance goes negative, requests return a 402 Payment Required error until you top up.
You can always check your rate limit remaining credits on your API key by making a GET request to this endpoint: https://openrouter.ai/api/v1/key