1. Creating an Anthropic account
- Go to console.anthropic.com and sign up with an email address
- Verify your email
- Add a small top-up under "Billing" (a $5 top-up covers thousands of Haiku 4.5 messages as a rough guide)
Signing up itself is free. Since you can only spend up to what you've topped up, there's no risk of runaway charges.
2. Generating an API key
- Open "API Keys" in the console's left-hand menu
- Click "Create Key" and give it a descriptive name (e.g. "For TOKENSE")
- Copy the key shown (a string starting with sk-ant-...)
3. Pasting it into TOKENSE
- Open tokense.net
- Paste your copied API key into the settings screen
- Save it, and you can start chatting immediately
The pasted key is stored only in this device's browser (localStorage) and is never sent to TOKENSE's servers. The only outbound traffic is to Anthropic's API (plus one daily exchange-rate lookup for currency display).
4. Common errors and fixes
| Error | Cause and fix |
|---|---|
| invalid x-api-key | Usually a copy-paste mistake (stray whitespace or line break). Copy the key again from the console |
| credit balance is too low | Your top-up balance ran out. Add more under "Billing" in the console |
| rate limit exceeded | Happens after a burst of requests in a short time. Wait a moment and retry |
5. Managing keys across multiple devices and apps
If you plan to use Claude on both your phone and your laptop, or alongside other BYOK-compatible apps besides TOKENSE, it's worth generating a separately named key for each device or app rather than reusing one key everywhere. Doing so gives you a few concrete benefits:
- The console's Usage view lets you see exactly how much each device or app has consumed
- If unusual activity shows up on one key, you can revoke just that one without affecting anything else
- You can clean up and delete keys for apps you've stopped using, individually
It's a bit more setup work, but generating a key only takes a few seconds. Treating it as "one key per device, one key per app" from the start makes everything easier to manage later.
FAQ
FAQ
- Q. Do I need a credit card to get an API key?
- A. You need to register a card when you add a small top-up under Billing. Creating the account itself is free.
- Q. Can I reuse the same key in multiple apps?
- A. Technically yes, but it's harder to track usage and revoke access selectively. It's safer to generate a separately named key per use case.
- Q. What if I accidentally exposed my key?
- A. Immediately revoke it from the "API Keys" section in the Anthropic console and generate a new one.
- Q. Is there a limit on how many keys I can create?
- A. The console allows multiple keys, though any specific limit is subject to change — check the Anthropic console for the current policy.
- Q. Can I rename a key after creating it?
- A. The console's management screen typically lets you edit a key's label. Giving keys clear, descriptive names makes it much easier to tell them apart later.