OpenRouter: sign up & create a key

What is an API key?

In this workshop, you will build your workflow in Sim and get AI responses through OpenRouter. Sim needs a private code that gives it permission to use AI through your OpenRouter account. This is an API key.

API keys also connect other programs and services, not just Sim. A key is different from your login password, but someone with it could use your account’s allowance or credits. Keep it safe like a password and do not share it.

If you already have a usable OpenRouter API key, you can register it in step 3 without creating another.

Create an API key

If you have just created an account: OpenRouter may already show an automatically created default key. Leave that key as it is and create a separate workshop key using the steps below. Do not delete the default key.

1. Open OpenRouter (new tab) and sign up or sign in.
2. If email verification is requested, complete it using the message in your inbox. Check spam or junk if the message is missing.
3. While signed in, open the API Keys page (new tab).
4. Select Create API Key (or the option to create a new key) and give it a name you will recognize later, such as polyu-workshop. This is just a label to distinguish your keys, so you can choose any name.
5. Create the key and select its copy button. Copy the generated long code, not the name you gave the key.
6. Keep this screen open until you have registered the key in Sim in the next step.

Security note: Do not send your API key to others or include it in screenshots. If you need to keep it for later, use a secure personal storage method such as a password manager.